| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light source of high output which is improved in light extraction efficiency in such a configuration that a plurality of light emitting elements are laminated through an adhesion layer. <P>SOLUTION: Refractive indexes of the adhesion layer 21, an insulating protection layer 26, and a substrate 13 are so selected as to satisfy (n2×n3)<SP>1/2</SP>-0.05≤n1≤(n2×n3)<SP>1/2</SP>+0.05, wherein n1 is the refractive index of the adhesion layer 21; n2 is the refractive index of the insulating protection layer 26; and n3 is a bonding layer of the substrate 13. <P>COPYRIGHT: (C)2009,JPO&INPIT |
