电子内窥镜光学系统设计

Optical System Design of Electronic Endoscope

内窥镜观察范围大,并且观察系统多与手术器械相配合,具有广角长工作距的特点,因此物镜采用非对称反远距结构。设计的光学系统采用尺寸为3.30mm×2.95mm CCD接收成像,像元大小为3.275μm,实现了短焦距(1.7mm)、细径化(Φ=5.5mm)、大视场(100°)、长工作距(50mm)的光学特性。由于该系统为大视场光学系统,会有较大畸变,针对反远距物镜分析了其结构特点和像差特性,通过计算得出系统各个参数,并合理的引用非球面,达到了提高系统成像质量并且降低系统畸变的目的,利用ZEMAX光学设计软件给出了设计实例,并已经应用到实际生产中。

The objective in this paper is an electronic endoscope,to meet the requestment of wide range for endoscopic obser-vation and observation system more compatible with surgical instruments, thus it is characterized by a wide-angle and long working distance, so the objective lens adopt structure of asymmetrical inverse distance. The optical system adopts 3.30 ＆#215; 2.95mm CCD as receiver. The pixel size is 3.275μm,which realizes the optical properties of short focal length（1.7mm）,small diameter,a large field of view（100 degrees）and long working distance（50mm）. Since the system is a large field optics sys-tem, there will be a larger distortion. For the inverted telephoto objective in this paper, the structure characteristics and the optical aberration are analyzed,and the example is presented by ZEMAX software,through the calculation,system parame-ters are obtained,Adopting the aspheric surface reasonably can enhance the imaging quality of system,reduce the system dis-tortion,and the example has been applied to actual production.