Design of an Objective Lens for Womb Electronic Endoscope with High Definition, Non-blind Spot and Thinner Outer Diameter
高清晰低畸变细径化电子内镜物镜设计

An electronic endoscope objective lens with a field-of-view of 74° was designed for medical application. The electronic endoscope is with an outside diameter of 8 mm that makes the anaesthesia avoidable, and a flexible head that realizes non-blind spot diagnosis. The effective focus length of the objective is 4 mm while the back working length is 4.8 mm. The maximum distortion of the system is less than 4% and the maximum field curvature is 0.27 mm. In order to improve the imaging performance, the aspheric surface into the system of 5 elements was introduced. The designed optical system especially matches the requirements of a CCD detector with 0.25 inches and SVGA display model.