CPC Subgroup
G02B 3/08 with discontinuous faces, e.g. Fresnel lens
Full Title
Simple or compound lenses > with non-spherical faces (G02B3/10 takes precedence) > with discontinuous faces, e.g. Fresnel lens
G02B 3/08 Simple or compound lenses > with non-spherical faces (G02B3/10 takes precedence) > with discontinuous faces, e.g. Fresnel lens