一款超小型广角医用内窥镜镜头的设计

Design of an Ultra-Small Wide-Angle Medical Endoscope Lens

为了满足现代医疗内窥镜对小型化、便携性以及广角的需求,结合现代塑胶非球面和注塑成型技术,使用Zemax光学设计软件设计了一款超小型医疗用广角内窥镜镜头。该镜头使用了两片塑胶非球面,其光学结构为负正结构形式且分别位于孔径光阑的两侧。设计结果显示:该镜头的F数为6.0,全视场角为150°,系统总长为3.38 m,镜头外径为2 mm。该设计在1/2奈奎斯特频率处,各视场均大于0.45。通过对该镜头的测试,其图像清晰,能够较好地观察到人体内部组织的细节,满足医疗使用的要求。

In order to meet the miniaturization, portability and wide-angle needs for modern medical endoscopes, an ultra-small medical endoscope lens with a wide angle is designed combining with modern plastic aspherical and injection molding technology and using Zemax optical design software. The lens uses two plastic aspheric lens, whose optical structure is in the form of a negative-positive construction and are located by the sides of the stop. The design result shows that F number is 6.0,the field of view is 150° , the total length of the lens is 3.38 m and the lens diameter is 2 ram. The modulation transfer function （MTF） of all fields at half of Nyquist frequency are more than 0.45. Through the test of the lens, the image is clear and the detail of human internal organization can be well observed, which meets the requirement of medical application.