目前国内用于激光标刻机的F-Theta镜头的工作面积一般不超过420 mm。国外虽有面积较大的F-Theta镜头,但结构复杂。通过初级像差分析,确定了镜头的初始结构参量,利用光学设计软件优化得到了工作面积为680 mm的F-Theta镜头,它由四片两种普通玻璃球面透镜构成,光学筒长不到100 mm,具有结构简单紧凑,聚焦性能接近衍射极限、线性畸变小的优点,满足大工作面打标的使用要求。

The working area of F-Theta lens is generally not larger than 420 mm in diameter interiorly when used in laser marking system. F-Theta lenses with larger working areas overseas are of complicated structures. F-Theta lens with its working area as large as 680 mm in diameter is obtained by determining the parameters of initial structure through analysis of the primary aberration and optimizing the initial structure with optical design software. The designed system is compact and composed of only four spherical lenses made up of two kinds of common optical glasses. Its tube length is less than 100 mm. But its focusing performance is diffraction-limited and its distortion relative to the F-Theta linear relation is small. The system satisfies the requirements of marking on a large area.