Controlling a MEMS Deformable Mirror in a Miniature Auto-Focusing Imaging System

被引:10
作者
Wei, Hsiang-Chun [1 ]
Chien, Yuan-Heng [1 ]
Hsu, Wei-Yao [2 ]
Cheng, Yuan-Chieh [2 ]
Su, Guo-Dung J. [1 ]
机构
[1] Natl Taiwan Univ 1, Grad Inst Photon & Optoelect, Taipei 10617, Taiwan
[2] Instrument Technol Res Ctr, Hsinchu 300, Taiwan
关键词
Auto-focusing; camera system; deformable mirror (DM); focus value; microelectromechanical system (MEMS); AUTOFOCUS CAMERA;
D O I
10.1109/TCST.2011.2165543
中图分类号
TP [自动化技术、计算机技术];
学科分类号
0812 ;
摘要
Conventional auto-focusing camera modules adjust their optical focus bymoving lenses. Although motors, such as stepping motors or voice coil motors, can change the lens position with great precision and thus vary the image sharpness, large volume and excess power consumption remain critical issues for mobile device applications. This paper discusses an auto-focusing camera module that adopts a microelectromechanical system (MEMS) deformable mirror (DM) with variable focusing capability to replace mechanical motors. The DM used in this paper can provide 20 diopters of focusing capability, which is one order of magnitude higher than silicon-based DMs, so the autofocus module can be compact enough for mobile devices. Because of the characteristics of MEMS DMs, we proposed a "percentage-drop" searching algorithm to find a sharp image based on a focus value calculation. The average auto-focusing time is 45% faster than the global searching method.
引用
收藏
页码:1592 / 1596
页数:5
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