High-Speed Auto-Focusing Systemfor CCM Test Handlers

摘要

This paper proposes a new auto-focusing system imbedded at the test handler machine of compact camera module (CCM). The camera-link based interface board is designed for high-speed image transmission. The auto-focusing algorithm is also proposed to test and handle the lens position of CCM efficiently. The max-min-difference (MMD) method to compute a focus value and two-stage searching method to detect a best focus position are newly developed to reduce the computational time, which results in the improvement of productivity of test handler machine. Experimental results are presented to verify the usefulness of proposed system.