Fig. 1. Schematic of overall system structure

Fig. 2. Schematic of lighting lightpath

Fig. 3. Schematic of analysis principle of collimating lens

Fig. 4. Design of microlens array. (a) Schematic of design principle of microlens; (b) schematic of ray tracing of microlens array

Fig. 5. Structure diagram of lighting system

Fig. 6. Output light intensity curves of collimating lens

Fig. 7. Illumination of target surface in lighting system. (a) Schematic of plane distribution; (b) schematic of distribution curve

Fig. 8. Schematic of inverse telephoto principle

Fig. 9. Initial structure of double Gaussian imaging system

Fig. 10. Field curvature and distortion of double Gaussian structure after focal length scaling

Fig. 11. Half structure of double Gaussian structure

Fig. 12. Point plot and field distortion of 35° field. (a) Point plot; (b) field distortion

Fig. 13. Diagram of ray tracing

Fig. 14. Image quality results. (a) Transfer function diagram; (b) field curvature and distortion; (c) mesh distortion; (d) vertical axis chromatic aberration