| 摘要 |
PROBLEM TO BE SOLVED: To further improve the using efficiency of light from an optical semiconductor device. SOLUTION: This light-emitting element is provided with a surface light source 100 in a light-diffusing type and a structure 102 formed near the outer periphery of the surface light source, so that an arbitrary space can be surrounded by reflecting faces, and the inside part is packed with a medium 103 having arbitrary refractivity in an arbitrary range, and when the refractivity of the medium 103 to be packed is defined as N, the size of the outgoing face of the medium is set so as to be not less than N/Nx(Nx: the refractivity of a medium brought into contact with the medium to be packed at the outgoing face) times as large as the size of the incident face of the medium. |
