Patent ID: 6844989

Claim:
A lens system installed in a mobile communication terminal, comprising: a first lens including at least one aspherical plane and having a positive refractivity; a perforated iris separated from the first lens by a designated distance for preventing unnecessary incident light from being incident onto an optical system; a second lens separated from the perforated iris by a designated distance, including at least one aspherical plane and having a positive refractivity; and a third lens separated from the second lens by a designated distance, including at least one aspherical plane 15 and having a negative refractivity; wherein the first lens, the perforated iris, the second lens and the third lens are arranged sequentially from a subject, and the perforated iris is located between the first lens and the second lens; and wherein the first lens satisfies the following expression (1) in terms of Dower for obtaining good aberration characteristics of the optical system, and the following expression (2) so as to define a shape thereof for preventing spherical aberration and distortion from occurring in the optical system; 0.5 <f 1 /f< 3.5 (1) 0.3 <r 1 /f< 1.0 (2) here, f1 is a focal distance of the first lens, f Is a focal distance of the entire optical system, and r1 is a radius of curvature of a first aspherical plane of the first lens.