Fig. 1. Light path of zoom projection lens under different focuses. (a) Long focus; (b) short focus

Fig. 2. Opto-mechanical structure of zoom projection lens. (a) General structure; (b) lens structure

Fig. 3. Mesh model of zoom projection lens

Fig. 4. Temperature field distribution of zoom projection lens under different temperature variations. (a) 13.1 ℃ (b) 21.3 ℃

Fig. 5. Displacement nephogram when temperature variation is 25 ℃

Fig. 6. Schematic of deformation based on vector height

Fig. 7. Fitting results of thermal deformation of aspheric surfaces. (a) Aspheric surface 1; (b) aspheric surface 2

Fig. 8. MTF curves of long-wave wide field under different temperatures. (a) 10 ℃; (b) 35 ℃

Fig. 9. MTF curves of long-wave small field under different temperatures. (a) 10 ℃; (b) 35 ℃

Fig. 10. MTF curves of medium-wave wide field under different temperatures. (a) 10 ℃; (b) 35 ℃

Fig. 11. MTF curves of medium-wave small field under different temperatures. (a) 10 ℃; (b) 35 ℃