Method for emitting multicolored light

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PROBLEM TO BE SOLVED : To provide a light emitting method for emitting a multicolored light at an excellent light emitting efficiency. SOLUTION : When an LED element 20 emits a blue light, a part of the energy is absorbed by a phosphor 10 to excite a rare-earth or transition metal element added to a green fluorescent layer 13G and a red fluorescent layer 13R, respectively. At the same time, the rare-earth or transition metal element is excited by energy generated by recoupling carriers confined in each fluorescent layer by the energy also. Thus, a green light and a red light are emitted at a high efficiency from the green fluorescent layer 13G and the red fluorescent layer 13R. As the composition of the fluorescent layer has no electric restraints, more rare-earth or transition metal elements can be added than in the case where an electric field is afforded. This point can contribute to enhancements in the light emitting efficiency. By mixing a blue light emitted from the LED element 20 with a green light and a red light emitted from the phosphore 10, the light emission of a white light by three-color mixture which is more excellent in color development properties than two-color mixture is materialized at a low cost. COPYRIGHT : (C)2005, JPO&NCIPI