大视场自由曲面复眼设计研究

Study and Design on Freeform Surface Compound Eye with Large Field of View

在大视场小体积的人造复眼结构中,倾斜的边缘子眼成像时存在较大的轴外像差。提出一种复眼结构,利用光线在子眼中的折转与自由曲面矫正像差,提高了边缘子眼的成像质量,进而增大了复眼结构的视场角。设计出5组子眼对180°视场成像,每组对应特定的视场范围。利用光学仿真软件CodeV对5组子眼分别做了光学仿真,得到了各组子眼的像差曲线,光学传递函数MTF曲线。结果表明,在整个180°视场范围内,频率为100 lp/mm时,MTF值均大于0.2,畸变在30%以内,复眼具有良好的成像质量。

The ommatidia arranged at the edge have great off-axis aberrations in artificial compound eye structure with wide Field of View （FOV） and small volume. A new compound eye structure is presented, where the ommatidia are designed as freeform prisms. With the light passing through the freeform surface and folding in the ommatidium, the off-axis aberrations are well corrected. Therefore, the image quality of the ommatidia arranged at the edge is improved, and the FOV of the structure is enlarged. To image 180° FOV, this structure contains 5 groups of ommatidia with a particular FOV correspondingly. The model of each group is designed and the ray trace is completed based on the optical simulation software codeV. The results demonstrate that the compound eyes structure has high image quality for the entire 180° FOV. On the one hand, the modulation transformation function MTF is greater than 0.2 at the frequency of 100lp/mm, and on the other hand, the distortion is less than 30%.