为了实现高清数字化医疗内窥成像,使用成像质量良好的耦合透镜系统耦合内窥镜目镜和CCD相机,成为高清视频内窥镜。基于实际应用的要求,设计了一个适用于耳鼻喉科内窥镜耦合CCD相机的透镜系统,该系统可以用于1/1.8 in(1 in=25.4 mm)、200万像素的CCD相机成像,并且具有12°视场角,4.4的F数。在调制传递函数(MTF)大于0.1判据下,透镜系统各视场的分辨率都在111 lp/mm以上,在全视场范围都能取得很好的成像效果。实际测试表明,该系统光学成像清楚,图像细节表现明显,分辨率达到了高清成像的要求,虽然结构简单,但达到了预期的设计目标,不但有利于加工和装配,而且降低了大量的成本。

In order to achieve high-definition digital medical endoscopic imaging,a coupling lens system with high imaging quality is needed to couple the eyepiece of an endoscope and the camera.According to the clinical application requirements,one coupling lens system suitable to otolaryngology was designed for a CCD camera with 1/1.8 inch imaging area and 2 megapixels.The coupling lens system has a 12° angle of field and F number of 4.4.Under the criterion of the modulation transfer functions(MTF) of the coupling lens system in each field are greater than 0.1,and the resolution is better than 111 lp/mm so that it can achieve excellent imaging quality in the whole field of view.The testing results have shown that the designed coupling lens system is able to obtain a high-definition resolution imaging with uniform illumination.Although it is very simple in the structure,the expected results have been accomplished.It is not only better to manufacture and assemble but also save a lot of cost.