| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an eyepiece optical system that is easy to manufacture, able to restrain occurrence of flare, is inexpensive, is satisfactorily corrected in various aberrations such as chromatic aberration of magnification, and has a long eye relief, and to provide an optical device having this eyepiece optical system. <P>SOLUTION: An eyepiece optical system 3 used for the optical device such as a telescopic optical system TS comprises, in order from an observation eye side, a first lens group G1 having a lens with positive refractive power; a second lens group G2 that has a diffractive optical element GD formed from two diffraction element components L22 and L23 and two optical members L21 and L24 joined to one sides of these two diffraction element components, and having a diffractive optical surface D in which diffraction grating grooves are formed in the other sides of the two diffraction element components L22 and L23 and they are arranged opposite to each other; and a third lens group having a cemented lens composed of a positive lens 31 and negative lens L32 cemented together and having positive refractive power as a whole. At least the optical members L21 or L24 of the diffractive optical element GD is a parallel flat plate. <P>COPYRIGHT: (C)2012,JPO&INPIT |
