Abstract: An illumination optical system of a 3-dimensional (3D) image acquisition apparatus and a 3D image acquisition apparatus including the illumination optical system. The illumination optical system of a 3D image acquisition apparatus includes a beam shaping element which outputs light having a predetermined cross-sectional shape which is proportional to a field of view of the 3D image acquisition apparatus. The beam shaping element may adjust a shape of illumination light according to its cross-sectional shape. The beam shaping element may uniformly homogenize the illumination light without causing light scattering or absorption.

Abstract: Provided is a zoom lens. The zoom lens includes a first lens group with a positive refractive power, a second lens group with a negative refractive power, a third lens group with a positive refractive power, a fourth lens group with a negative refractive power, and a fifth lens group with a positive refractive power. The first through fifth lens groups are sequentially arranged toward an image side from an object side, and the second, fourth, and fifth lens groups move long the optical axis during zooming.