为了获得高质量的虹膜图像,采用光学设计软件ZEMAX设计了一款手机虹膜识别镜头,该镜头由4片塑料非球面透镜组成,工作距离为200~330 mm,总长为4.09 mm,F数为2.4。设计结果显示,工作距离为275 mm时,镜头在1/2奈奎斯特频率处的调制传递函数大于0.4,光学畸变小于0.6%,相对照度大于83%。通过像质评价及公差分析可知,该光学系统的畸变小,可变工作距离大,像质优异且性能稳定,可以满足虹膜识别镜头的加工要求。

To obtain high-quality iris images, a phone iris-recognition lens is designed using the optical design software ZEMAX in this study. The phone lens comprises four plastic aspheric lenses. The total working distance, total length, and F number of the phone lens are 200--330 mm, 4.09 mm, and 2.4, respectively. In the design results, the modulation transfer function at 275 mm exceeds 0.4 at one-half the Nyquist frequency of the lens. The distortion is lower than 0.6%, and the relative illumination exceeds 83%. Image evaluation and tolerance analysis confirm that the system has small distortion, a large variable working distance, excellent image quality, and stable performance, thus meeting the processing requirements of iris recognition lenses.