| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain an optical system which has a superior antireflection effect and hardly generates a ghost and from which high optical performance can easily be obtained without sacrificing the image formation performance or total miniaturization thereof, even when a substrate having a small wavelength dispersion value and a low refractive index is used. <P>SOLUTION: The optical system is provided with: the substrate consisting of optical glass exhibiting ≤1.65 refractive index to the d-line; and at least one optical element constituted so that an antireflection structure, which is formed by using an inorganic material as a construction material and composed of a plurality of structure parts having the average pitch smaller than the wavelength to be used, is formed on at least one optical surface among light entrance/emission optical surfaces of the substrate. <P>COPYRIGHT: (C)2011,JPO&INPIT |
