The present invention has as its object the provision of a fluorescence light source device in which, when a fluorescence member including a periodic structure layer formed on the surface is irradiated with excitation light, a rise in the temperature of the fluorescence member is suppressed and the reflection of the excitation light is reduced while fluorescence generated inside the fluorescence member is effectively used and allowed to exit to the outside at high efficiency, and high luminous efficacy is obtained accordingly. The present invention has as another object the provision of a method for producing the fluorescence light source device.

The fluorescence light source device of the present invention includes a fluorescence member formed from a phosphor composed of single crystal or polycrystal and excited by excitation light. A periodic structure layer made of a high refractive index material having a refractive index of not less than the refractive index of the fluorescence member is formed on the surface of the fluorescence member. The periodic structure layer has a surface with a periodic structure having a periodic array of conical or truncated projections and formed by an etching process. The aspect ratio which is a ratio of the height of the projections to the pitch in the periodic structure is within a range of 0.5 to 0.9.

An LED light bulb includes a bulb shell, a bulb base, a stem, conductive supports, an LED filament, and a supporting arm. The bulb base is connected to the bulb shell. The stem is connected to the bulb base. The conductive supports are connected to the stem. The LED filament includes a filament body and two conductive electrodes. The conductive electrodes are at two ends of the filament body and connected to the conductive supports. The filament body is around the stem. The supporting arm is connected to the stem and the filament body. In a height direction of the LED light bulb, H is a distance from a bottom to a top of the bulb shell. A first height difference is defined between the two conductive electrodes and is from 0 to 1/10H. The filament body is curved to form a highest point and a lowest point. A second height difference is defined between the highest point and the lowest point. The first height difference is less than the second height difference.

A phosphor wheel includes: a substrate; a light reflection layer disposed on one surface of the substrate; a phosphor layer; and a bonding layer which is located between and bonds the light reflection layer and the phosphor layer, wherein the bonding layer contains a particle which is higher in thermal conductivity than a base material of the bonding layer and higher in light reflectance than the light reflection layer.

In a light emitting device and system providing white light with various color temperatures are provided, a light emitting device includes a light emitting element (LED) that is operated by a driving bias and emits first light, and a phosphor layer including a phosphor that partially wavelength-converts first light and emits second light, thereby emitting white light using the first light and the second light, wherein the phosphor has a maximum conversion efficiency at a first level of the driving bias, and the LED has a maximum conversion efficiency at a second level of the driving bias, the first level being different from the first level.

A phosphor device of an illumination system, which emits a first waveband light, includes a substrate and a first phosphor layer. The first phosphor layer includes a first phosphor agent and a second phosphor agent. The first phosphor agent is formed on the substrate for converting the first waveband light into a second waveband light. The second waveband light comprises a first color light and a second color light. The second phosphor agent is distributed over the first phosphor agent for converting the first waveband light into the second color light so as to increase the luminous intensity of the second color light. Therefore, the luminous intensity of the second color light can be effectively increased.

A light emitting assembly and method for making optionally includes a light source configured to emit light substantially about a plane, the light having a first spectral profile, and a material configured to shift light incident from the light source from the first spectral profile to a second spectral profile and emit light as shifted. The light, as shifted, is emitted from the assembly generally along an axis orthogonal to the plane.

A lamp for a vehicle includes a light source generating a light. A reflector is rotatably coupled with a support. A reflecting body is connected to the reflector to rotate along with a rotation of the reflector, receives the light from the light source, and reflects the light to the reflector.

A wavelength conversion material array is provided, including a system comprising: a light source configured to emit excitation light at an excitation wavelength; a heatsink; a wavelength conversion material located on the heatsink, the wavelength conversion material comprising a relative wavelength conversion area of unity divided into an array of spots, a number of the spots in a range of 4 to 12, the wavelength conversion material configured to emit light at a wavelength greater than the excitation wavelength when irradiated by the excitation light; and, an array of lenslets configured to: receive the excitation light from the light source and irradiate each of the spots of the wavelength conversion material with the excitation light, the lenslets in a one-to-one relationship with the number of spots; and collect the light emitted by the wavelength conversion material.

Provided is a process for producing a wavelength conversion member which can suppress the reaction between inorganic nanophosphor particles and glass to suppress the deterioration of the inorganic nanophosphor particles, and the wavelength conversion member. The process for producing a wavelength conversion member includes the steps of: preparing inorganic nanophosphor particles 1 with an organic protective film formed on respective surfaces thereof; and mixing the inorganic nanophosphor particles 1 with glass powder and firing a resultant mixture in a temperature range where the organic protective films remain as retained films 3.

The present invention has as its object the provision of a fluorescence light source device that can obtain high luminous efficiency. A fluorescence light source device of the present invention includes a wavelength conversion member that emits fluorescence by excitation laser light. The wavelength conversion member has an excitation laser light receiving surface including a periodic structure having a periodic array of conical or truncated projections with an aspect ratio, which is a ratio of the height of the projection to the pitch in the periodic structure, of not lower than 0.2. The wavelength conversion member is formed from a phosphor composed of a polycrystal and contains a micro-scatterer with a refractive index of not lower than 1.0 for scattering the excitation laser light and fluorescence emitted from the phosphor. A ratio (T/R) between a light transmission percentage T [%] in the wavelength conversion member and a light reflection percentage R [%] in the wavelength conversion member is 1 to 20.