| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a wavelength conversion element in which etendue as a light source can be suppressed, and high light usage efficiency is achieved by suppressing optical loss in a projector illumination system in a succeeding stage. <P>SOLUTION: In a circular wavelength conversion element 901 having a substrate 3 and a phosphor layer 2 emitting phosphor light of a wavelength range different from excitation light, the phosphor layer 2 is formed on a side face 3a of the substrate 3. <P>COPYRIGHT: (C)2012,JPO&INPIT |
