Fig. 1. Composition diagram of collimating lens

Fig. 2. Arithmetic design principle of negative focal distance transmission structure

Fig. 3. Arithmetic design principle of virtual light source

Fig. 4. Arithmetic design principle of reflection structure

Fig. 5. Angles of incidence on S5

Fig. 6. Collimating lens. (a) Discrete point matched curve; (b) 3D solid model

Fig. 7. Numerical relationship between refraction angle and incidence angle

Fig. 8. Volumes of different range of reflection collimating angles

Fig. 9. Ray tracing results of collimating module

Fig. 10. Light spot before collimating module optimization

Fig. 11. Photomatric data before collimating module optimization

Fig. 12. Light spot after collimating module optimization

Fig. 13. Photomatric data after collimating module optimization