Abstract: The UV light irradiation device includes a chamber having a space for accommodating therein an irradiation target, and a plurality of light-emitting diodes provided at an inner surface of the chamber. A controller is configured to control lighting of the plurality of light-emitting diodes. The light-emitting diodes include a plurality of first light-emitting diodes, each having a peak wavelength in a range of 280 nm to 310 nm, and a plurality of second light-emitting diodes, each having a peak wavelength in a range of 310 nm to 405 nm. The controller includes a lighting control section that is configured to light up the first light-emitting diode before lighting up the second light-emitting diode.

Abstract: The UV light irradiation device includes a chamber having a space for accommodating therein an irradiation target, and a plurality of light-emitting diodes provided at an inner surface of the chamber. A controller is configured to control lighting of the plurality of light-emitting diodes. The light-emitting diodes include a plurality of first light-emitting diodes, each having a peak wavelength in a range of 280 nm to 310 nm, and a plurality of second light-emitting diodes, each having a peak wavelength in a range of 310 nm to 405 nm. The controller includes a lighting control section that is configured to light up the first light-emitting diode before lighting up the second light-emitting diode.

Abstract: A phosphor composition contains phosphor particles and a water-soluble rare earth compound uniformly covering the surfaces of the phosphor particles. The rare earth compound is present in an amount of from 0.001 to 5% by weight in terms of the corresponding rare earth oxide, based on the weight of the phosphor particles.

Abstract: A phosphor composition contains phosphor particles and a water-soluble rare earth compound uniformly covering the surfaces of the phosphor particles. The rare earth compound is present in an amount of from 0.001 to 5% by weight in terms of the corresponding rare earth oxide, based on the weight of the phosphor particles.

Abstract: A phosphor composition and a lamp having a phosphor film formed of the composition. The composition contains red, green and blue luminescence components. The blue component emits blue light by the excitation of 253.7-nm ultraviolet light. It has a main luminescence peak wavelength of 460 to 510 nm, and a half width of the main peak of a luminescence spectrum of not less than 50 nm. The color coordinates of the luminescence spectrum of the blue component falls within a range of 0.15.ltoreq.x.ltoreq.0.30 and of 0.25.ltoreq.y.ltoreq.0.40 based on the CIE 1931 standard chromaticity diagram. The blue component has a spectral reflectance of not less 80% at 380 to 500 nm, assuming that a spectral reflectance of a smoked magnesium oxide film is 100%.

Abstract: A light-emitting composition includes a phosphor material, and an inorganic white powder material. The inorganic powder material is doped with a dopant of Ti, Ce, Cd, Cs, Sb, K, Sc, Zr, Ge, Al, Lu, La, Gd, Tb, B and/or Si. The light-emitting composition can be applied to the inner surface of a bulb of a fluorescent lamp.