Title :
An autofocusing measurement system with a piezoelectric translator
Author :
Zhang, Ji-hua ; Cai, Lilong
Author_Institution :
Dept. of Mech. Eng., Hong Kong Univ., Hong Kong
fDate :
9/1/1997 12:00:00 AM
Abstract :
An autofocusing system that consists of a compact disc (CD) optical head and a piezoelectric translator (PZT) is developed for measuring the displacement or profile of a tested surface. The displacement or the profile of the tested surface can be obtained with varying accuracy by measuring the curve of the driving voltage to the expansion distance of the PZT or by using a secondary sensing device of displacement. The resolution of the system can reach 10 nm and the accuracy is 0.05 μm. Some design considerations, such as the control algorithm of the focus servo and error analysis of the system, are addressed in this paper
Keywords :
error analysis; feedback; lead compounds; measurement by laser beam; optical self-focusing; photodetectors; piezoceramics; servomechanisms; spatial variables measurement; compact disc optical head; error analysis; feedback; laser autofocusing system; optical transducer; piezoelectric translator; servomechanism; Actuators; Displacement measurement; Laser feedback; Microscopy; Optical feedback; Optical fiber devices; Optical fiber sensors; Optical interferometry; Optical sensors; Surface structures;
Journal_Title :
Mechatronics, IEEE/ASME Transactions on
DOI :
10.1109/3516.622974
