Patent ID: 7760450

Claim:
A lens system comprising, in order from the object side: a first lens comprising a first optical portion and a first mounting portion surrounding the first optical portion; and a second lens comprising: a second optical portion with a convex object side surface, the convex object side surface comprising an optical surface at the center thereof and a first connecting surface surrounding the optical surface; and a second mounting portion surrounding the second optical portion, the second mounting portion comprising a second connecting surface surrounding the first connecting surface, wherein the lens system satisfies the following condition: tan - 1 ⁡ ( D ⁢ ⁢ 1 sag ⁢ ⁢ 1 ) ≤ θ ⁢ ⁢ 1 ≤ tan - 1 ⁡ ( D ⁢ ⁢ 1 sag ⁢ ⁢ 1 ) × ( 1 + Da - D ⁢ ⁢ 1 D ⁢ ⁢ 2 - D ⁢ ⁢ 1 ) wherein D 1 is the semi-diameter of the optical surface, sag1 is the height of the optical surface along the axis of the lens system, θ1 is an angle measured anti-clockwise from the first connecting surface to the axis of the lens system, Da is the outer semi-diameter of the first connecting surface, and D 2 is the outer semi-diameter of the second connecting surface.