Patent attributes
An eyepiece lens with protected Fresnel and diffractive surfaces. An eyepiece is provided with a first element having an optical axis and a diffractive structure comprising a plurality of diffraction facets formed on at least one surface of a first element, and a second element having a Fresnel structure comprising a plurality of Fresnel facets formed on at least one surface thereof, the respective draft angles of the Fresnel facets relative to the optical axis being proximate the respective incidence angles of their respective adjacent incident light rays of a nominal design so as to minimize light obscuration and scatter, the first element and the second element having essentially the same optical axis, the diffractive surface of the first element being adapted to compensate for chromatic dispersion introduced by the refractive properties of said first and second elements.
