YANG Yu, ZHAO Yu, YANG Ming, MENG Chuan rui

 

(Mechanical and Electrical College, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China)

 

 

Abstract: Aiming at the problem about fast, large quantities of automatic image acquisition, a method of hardware focusing was researched. The system detect the position through a PSD (Position Sensitive Detector) combined with principles of optics. The PSD conversion circuit was designed to convert from position to voltage. The electronic components used in this circuit were selected to meet the system requirement of and the accuracy. Correspondences between the change of position and the output data of PSD conversion circuit were obtained. The precise position of the focus was obtained through experimental data linearization. The results indicate that this hardware automatic focusing system have obvious advantages in precision and speed.

 

Key words: hardware automatic focusing; PSD sensor; PSD conversion circuit; linearization