Patent ID: 7830077

Claim:
A light-emitting device comprising: a first insulator, including a plurality of portions that are arranged so as to face each other; an emitter, which includes fluorescent particles and which is arranged in a space that is defined by those portions of the first insulator, wherein the emitter has a porous surface layer and is configured to emit light by a creeping discharge of the emitter, the creeping discharge being an electrical discharge that is produced in the porous surface layer of the emitter; a second insulator, which functions as a base for the first insulator and the emitter; a plurality of electrodes to generate an electric field in the space and the porous surface layer of the emitter; and a substrate, which faces the second insulator with the emitter interposed between them, wherein the ratio A 2 /A 1 of the cross-sectional area A 2 of the emitter to the cross-sectional area A 1 of a range surrounded with the first and second insulators and the substrate is greater than 0.4 but less than 1, the cross-sectional area A 2 of the emitter and the cross-sectional area A 1 of the range being on a plane that is perpendicular to the surface of the second insulator and that passes the center of the space.