Title: CCD auto-focusing algorithm for board to board socket inspection

Authors: Yean-Ren Hwang, Mei-Chao Liu, Yi-Ming Chen

Addresses: Department of Mechanical Engineering, National Central University, Chung-Li, Taiwan, Republic of China. Department of Inspection and Quality Control, FoxConn International Incorporation, Tu-Cheng City, Taipei, Taiwan, Republic of China. Department of Mechanical Engineering, National University, Taiwan, Republic of China

Abstract: This paper presents a new auto-focusing algorithm for CCD cameras used for the on-line board-to-board socket inspection. There are two focusing procedures in this algorithm, i.e. rough focusing and accurate focusing. First, the cameras lens is quickly moved to a position close to the best focusing position in the rough focusing procedure. Secondly, the lens is adjusted with small step length to achieve the best focusing position in the accurate focusing procedure. Compared to the traditional mountain climbing method, experiment results show that our algorithm reaches the best focusing position in fewer steps.

Keywords: auto-focusing; CCD; image processing.

DOI: 10.1504/IJCAT.2000.000244

International Journal of Computer Applications in Technology, 2000 Vol.13 No.3/4/5, pp.237-243

Available online: 15 Jul 2003 *

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