Stereo endoscope has played an important role in video 3-dimensional laparoscopy system. This paper presents the design principle of the stereo endoscope applying in minimal invasive surgery (MIS). Optical imaging technologies and instrument designs are discussed in relation to their current and future use in MIS procedures, then this paper analyses and compares three design methods of optical system, technical limitations in imaging technology are described along
with potential solutions. We put forward to a new optical design methods, namely, the system adopts two optical channels stereoscopic-imaging technique to replicate human binocular vision. A stereoscopic system for video endoscopes includes objective lens system, relay system, eyepiece system and the focused lens between eyepiece and
CCD. This paper present equal-angle pairs from symmetrically disposed object points to the system. This equal-angle property enables accurate object/image mapping onto the final stereo image pair. And the doctors can watch the true stereo image on the screen. This optical system has common characteristic compare to the common laparoscopy with long work distance-300mm and wide field-70 degree, as a result, the optical system have serious aberration related field, especially in distortion, the distortion can reduced from 15% to 5%.