| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical element which has a high curvature and is excellent in antireflection property entirely inside a lens effective diameter region to the light of a wide wavelength band. <P>SOLUTION: The optical element comprises a lens 1 in which the projection area S of a part where a surface inclination angle inside the effective diameter region E of the lens is ≥50° is ≥10% of the projection area S<SB>0</SB>of the effective diameter region E, and an antireflective film 2 formed on the surface of the lens. The antireflective film 2 has fine roughness whose three-dimensional average surface roughness is 5 to 100 nm on the surface. <P>COPYRIGHT: (C)2007,JPO&INPIT |
