Patent ID: 7658866
Filing Date: 2010-02-09
Classification: C09K,H01L,H05B

Abstract:
1. A fluorescent material comprising a first phosphor that at least partially converts energy emitted by an excitation source to a first emission spectrum that is different from the energy, and a second phosphor that at least partially converts the first emission spectrum to a second emission spectrum that is different from the first emission spectrum, wherein the first phosphor is a light-storing phosphor, which is a phosphor which is represented by the general formula: wherein M is at least one type selected from the group consisting of Mg, Ca, Ba, Sr and Zn; Q is at least one type selected from the group consisting of Pr, Nd, Dy, Er and Ho; a is a number that satisfies 0.0001≦a≦0.5 and b is a number that satisfies 0.0001≦b≦0.5, a peak wavelength of the emission spectrum of the first phosphor and a peak wavelength of the emission spectrum of the second phosphor have a relation of complementary colors, so that when the light created due to the peak wavelength of the first phosphor and the light created due to the peak wavelength of the second phosphor are mixed, the resulting light is in the white region, and the first and second phosphors are configured and arranged so that, when the fluorescent material is excited for about 15 minutes by ultraviolet irradiation having about 365.0 nm wavelength using a black light lamp with an intensity of 0.5 mW/cm