基于谐衍射的液体透镜变焦系统设计

Design of liquid lens zoom system based on harmonic

设计了一套基于谐衍射的液体透镜变焦系统。系统对可见光波段成像,视场角2ω为150°,焦距f′为20～120mm,可实现6~X变焦。采用两片液体透镜,利用电润湿原理,无需改变透镜间距,只需调整施加于之上的电压即可实现变焦,同时引入一个谐衍射面来校正大视场所引入的色差。系统的调制传递函数曲线在奈奎斯特频率60lp/mm时,短焦高于0.7,长焦高于0.6,成像质量很好。系统的设计既保证了成像的高清晰度,又减小了系统体积,可广泛应用于内窥镜和智能手机等微型变焦系统领域。

A liquid lens zoom system based on harmonic diffraction is designed.This system images in the visible waveband,the field angle 2ω=150°,the focal length f′=20-120 mm,and realizes six zoom.The system uses two liquid lenses,and the zoom can be realized by adjusting the voltage applied to them without changing the distance between the lenses.At the same time,a harmonic diffraction surface is introduced to correct the chromatic aberration introduced in the large field of view.When the Nyquist frequency of the system modulation transfer function curve is at 60lp/mm,short focal length is higher than 0.7,long focus is higher than 0.6,the imaging quality of the system is very good.The design of the system not only ensures the high definition of the imaging,but also reduces the volume of the system.It can be widely applied to the field of micro zoom system such as endoscope and smart phone.