Fig. 1. Spatial distribution of incident light

Fig. 2. Principle diagram of retroreflective ray formation. (a) Representation of single CCR element in X'Y'Z' coordinate system; (b) mirror path of retroreflective ray formation; (c) required areas for retroreflective ray formation

Fig. 3. Coordinate system transformation diagram. (a) X'Y'Z' coordinate system of CCR element; (b) X''Y''Z'' coordinate system of CCR element; (c) inclined angle of CCR element

Fig. 4. CCR classification diagram

Fig. 5. Schematic diagram of ray simulation

Fig. 6. CCR array modeling diagram. (a) α = 0°; (b) α = 5°; (c) α = 10°; (d) α = 15°

Fig. 7. Simulation results of retroreflection efficiency of CCR arrays with different α. (a) α = 0°; (b) α = 5°; (c) α = 10°; (d) α = 15°

Fig. 8. Influence of inclination angle on retroreflection efficiency

Fig. 9. Micro morphology of reflective film

Fig. 10. Measurement results of retroreflection coefficient of reflective film

Fig. 11. Results contrast of simulation and testing. (a) θ = 25°; (b) θ = 30°

Fig. 12. Splicing modeling of CCR array with α = 0°

Fig. 13. Retroreflection efficiency of splicing structures of CCR arrays with different refractive indexes. (a) Refractive index is 1.50; (b) refractive index is 1.58

Fig. 14. Comparison of different CCR arrays splicing modeling

Fig. 15. Splicing modeling of CCR arrays with α = 10° and α = -4°

Fig. 16. Simulation results of retroreflection efficiency. (a) CCR array with α = -4°; (b) splicing by CCR arrays with α= 10° and α = -4°; (c) different CCR arrays with ϕ = 0°; (d) different CCR arrays with ϕ = 90°; (e) different CCR arrays with θ= 25°