Patent ID: 6937396

Claim:
A hybrid lens comprising a refractive surface that refracts incident light and a diffractive surface that diffracts light exiting the lens, the diffracting surface designed by a sag satisfying the following Equation, s ⁢ ⁢ a ⁢ ⁢ g = f D + m ⁢ ⁢ λ - f D ⁢ 2 + r ⁢ 2 n - 1 , wherein f D is a distance from a center peak to a focal point of the hybrid lens, r is a height from a center axis to each peak of the hybrid lens, n is the refractive index of the hybrid lens λ is the wavelength of incident light, and m is an integer, and wherein the refractive surface has a low-order aspheric profile z satisfying the following Equation: z ⁡ ( r ) = c ⁢ ⁢ r 2 1 + 1 - ( 1 + k ) ⁢ c 2 ⁢ r 2 + Ar 4 + Br 6 + Cr 8 + Dr 10 , wherein c is a curvature of the refractive surface, k is a conic coefficient greater than O representing a shape of the refractive surface, and A, B, C and D are fourth, sixth, eighth and tenth aspheric coefficients respectively.