| 摘要 |
<P>PROBLEM TO BE SOLVED: To efficiently take out light from a light-emitting device while realizing miniaturization. <P>SOLUTION: The light-emitting device 2 is a light-emitting element radiating light from its upper surface 20 to an optical component 3. The optical part 3 is connected with the light-emitting device 2, so that light from the light-emitting device 2 is made incident from an incident surface 30, and the light which is made incident from the incident surface 30 outgoes from an outgoing surface 31 to the atmosphere. The outgoing surface 31 is a nearly elliptically spherical surface whose focal points are endpoints A and B maximizing a distance therebetween at the periphery of the light-emitting area of the light-emitting device 2. At the outgoing surface 31, an angle θ2 is made to be not larger than double of a critical angle θc decided based on the ratio of the refractive index n1 of the optical component 3 to the refractive index n2 of the atmosphere, so that a maximum incident angle θimax is not larger than the critical angle θc. The light radiated from the upper surface 20 of the light-emitting device 2 is incident from the incident surface 30 of the optical component 3, passes through the inside of the optical component 3, and reaches the outgoing surface 31 with an incident angle θi. The incident angle θi is not larger than the critical angle θc, most of the light having reached the outgoing surface 31 outgoes to the atmosphere without being reflected entirely. <P>COPYRIGHT: (C)2007,JPO&INPIT |
