A 3-dimensional image acquisition apparatus comprising: an objective lens for focusing an image of an object; an image processing unit for processing the image focused by the objective lens to generate a depth image signal using time of flight technology; an illumination optical system for illuminating the object to acquire depth information about the object; the illumination optical system comprising: a plurality of light sources; a beam shaping element for homogenizing light emitted from the light sources and changing a cross-sectional shape of the light; and a lens apparatus for focusing light emitted from a light-exit surface of the beam shaping element on an object, wherein a beam cross-sectional shape of the light emitted from the light-exit surface of the beam shaping element is the same as a cross-sectional shape of the beam shaping element, and a field of illumination of the illumination optical system coincides with a field of view of the 3D image acquisition apparatus; wherein the beam shaping element comprises an integrator rod; wherein the 3D image acquisition apparatus further comprises a control unit for controlling operations of the objective lens, the image processing unit, and the illumination optical system; and wherein the cross-sectional shape of the beam shaping element is the same as that of the field of view of the 3D image acquisition apparatus: further comprising a plurality of optical waveguides that guides the light emitted from the light sources into the beam shaping device, wherein a first end of each optical waveguide is attached to a respective light source, and a second end of each optical waveguide is attached to a side of the beam shaping element. an objective lens for focusing an image of an object; an image processing unit for processing the image focused by the objective lens to generate a depth image signal using time of flight technology; an illumination optical system for illuminating the object to acquire depth information about the object; the illumination optical system comprising: a plurality of light sources; a beam shaping element for homogenizing light emitted from the light sources and changing a cross-sectional shape of the light; and a lens apparatus for focusing light emitted from a light-exit surface of the beam shaping element on an object, a plurality of light sources; a beam shaping element for homogenizing light emitted from the light sources and changing a cross-sectional shape of the light; and a lens apparatus for focusing light emitted from a light-exit surface of the beam shaping element on an object, wherein a beam cross-sectional shape of the light emitted from the light-exit surface of the beam shaping element is the same as a cross-sectional shape of the beam shaping element, and a field of illumination of the illumination optical system coincides with a field of view of the 3D image acquisition apparatus; wherein the beam shaping element comprises an integrator rod; wherein the 3D image acquisition apparatus further comprises a control unit for controlling operations of the objective lens, the image processing unit, and the illumination optical system; and wherein the cross-sectional shape of the beam shaping element is the same as that of the field of view of the 3D image acquisition apparatus: further comprising a plurality of optical waveguides that guides the light emitted from the light sources into the beam shaping device, wherein a first end of each optical waveguide is attached to a respective light source, and a second end of each optical waveguide is attached to a side of the beam shaping element.