Patent ID: 8128268
Filing Date: 2012-03-06
Classification: F21V,F21Y

Abstract:
1. A light-emitting device, comprising: a rod-shaped light-emitting element; an LED light source; and a lens converging light from the LED light source to an end face of the rod-shaped light-emitting element; wherein the lens comprises a scattering area around a centerline of an extremity of the lens, and the scattering area scatters light in a proximity to the centerline to irradiate an inner peripheral surface of the rod-shaped light-emitting element with the light passed through an end face of the rod-shaped light-emitting element, and wherein the scattering area has a curved surface formed such that the light passed through a refraction plane of the scattering area is refracted toward the centerline, and such that the light passes through a point in the centerline that becomes further distant from the extremity of the lens with respect to a point on the refraction, plane by the light, becomes further distant from the centerline in a radial direction of the lens, with respect to a point on the refraction plane passed by the light becomes further distant from the centerline in a radial direction wherein a profile of the scattering area in a direction y perpendicular to a direction x of the centerline of an extremity of the lens is such that y changes with a fourth power of x.