Design and implementation of a class of autofocus control systems

According to the inspection applications of TFT-LCD, the autofocus systems have been widely applied in some fields. The performance of systems will affect on the results of the inspection. In terms of the analysis of the related technology, the automated focusing system architecture is presented. An optoelectronic sensor is used to acquire the signal of autofocus position. In order to improve the response time of systems, an assembly of piezoelectric motor and stepper motor is used for the mechanical components. A set of mechanical components is proposed. A flexible control process can implement the autofocus functions. The experimental results show that the autofocus system based on ARM can efficiently improve the real time performance.