Fig. 1. Structure diagram of the focusing mechanism

Fig. 2. Structure diagram of drive-transmission component

Fig. 3. Structure diagram of sensor component

Fig. 4. Schematic diagram of displacement measurement

Fig. 5. Diagram of experimental scene

Fig. 6. (a) Relative displacement curves and (b) residual error curves of focusing mechanism

Fig. 7. Sway precision curves of focusing mechanism while stepping motor rotates (a) clockwise and (b) anticlockwise