Patent ID: 7362518

Claim:
A wide angle lens having an optical axis, the wide angle lens comprising, in order from an object side: a first positive convex lens element made of an optical glass, the first positive convex lens element defining: a first convex aspheric surface on the object side; and a second aspheric surface approximating a plane; a second concavo-convex negative lens element made of an optical plastic, the second concavo-convex negative lens element defining: a third concave aspheric surface on the object side; and a fourth convex aspheric surface; and a third lens element made of an optical plastic, the third lens element defining: a fifth high-aperture convex aspheric surface on the object side; and a sixth aspheric surface being wave-shaped; wherein, each of the lens elements is disposed approximately symmetrically about an optical axis of the lens, and the lens elements statisfy the following data: Description R d D k First surface 2.184347 0.8588545 1.910503 0 Second surface 10.81372 0.7662999 2.074914 0 Third surface −1.22888 0.749922 2.074216 0 Fourth surface −1.500726 0.5489361 2.736669 0 Fifth surface 5.441956 1.257498 5.240696 0 Sixth surface 4.590265 0.8093014 5.700535 0 where: R is the curvature radius of the surface's optical center; d is the thickness of the lens element or space between surfaces of two adjacent lens elements; D is the effective aperture of the surface; and k is the conic constant, wherein the conic constant and the aspheric surfaces of the lens are defined by the equation, z = cr 2 1 + 1 - ( 1 + k ) ⁢ c 2 ⁢ r 2 + a 1 ⁢ r 2 + a 2 ⁢ r 4 + a 3 ⁢ r 6 + a 4 ⁢ r 8 + a 5 ⁢ r 10 + a 6 ⁢ r 12 ⁢ ⁢ ⋯ where: z is the surface sag; c=1/R, where R is the curvature radius of the surface's optical center; k is the conic constant; r is the distance from the optical axis; and a 1 , a 2 , a 3 , a 4 , a 5 , and a 6 are the aspheric coefficients; and surface data for the aspheric lenses are as follows: Description a 1 a 2 a 3 a 4 First surface 0 −0.0030892391 −0.0071110815 0.0011161245 Second surface 0 −0.025799536 −0.022383266 −0.012802254 Third surface 0 −0.0032416416 0.047130855 −0.0040239483 Fourth surface 0 0.03585162 0.032241911 0.0048140776 Fifth surface 0 −0.012922311 0.0014449276 −0.00006741227 Sixth surface 0 −0.02613585 0.0012729715 −0.000049252884 Description a 5 First surface −0.0037678149 Second surface −0.0015873624 Third surface 0.0080725451 Fourth surface 0.0044346914 Fifth surface −0.0000010470078 Sixth surface −0.0000016094932.