Fig. 1. Irradiation diagram of LED lamp beads

Fig. 2. Schematic diagram of free-form surface design of transmission part

Fig. 3. Schematic diagram of free-form surface design of reflection part

Fig. 4. Lens fitting bus

Fig. 5. Determination process of S₃ position

Fig. 6. Free-form lens simulation

Fig. 7. LED light source with and without lens light tracing before and after comparison

Fig. 8. Irradiation diagram of target receiving surface after lens correction

Fig. 9. Cartesian distribution diagram of rectangular coordinate system before and after lens addition

Fig. 10. Light panel layout design and light tracing diagram

Fig. 11. Irradiation diagrams of free-form lens and honeycomb lens

Fig. 12. Influence of surface machining errors of free-form lens on illuminance