Patent ID: 8009370

Claim:
A lens with an extended depth of focus, comprising: a plurality of first lens layers, each of the plurality of the first lens layers located outside of a predetermined radius from an optical axis and focusing light onto a corresponding linear region formed a predetermined distance from both ends of a focal curve located on the optical axis; and a plurality of second lens layers located within the predetermined radius from the optical axis, wherein each of the plurality of the first lens layers and each of the plurality of the second lens layers is axially symmetric and a surface of each of the plurality of the first lens layers and each of the plurality of the second lens layers satisfies the equation: ⅆ x ⅆ y = y β i - x - n ϕ n θ ⁢ ( β i - x ) 2 + y 2 , x ⁡ ( 0 ) = 0 , wherein n φ , n θ and β i represent a refractive index at an angle of incidence, a refractive index at an angle of refraction, and a focal length for i-th curved segments, respectively.