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★ 发芽土豆(金币+1):谢谢参与 2010-07-07 12:22:09 zhaoyan1989987(金币+15, 翻译EPI+1):非常感谢 2010-07-08 22:41:18
Cat-eye effect based surface damage effect detection of sensor in optical lens
It is the actuality that optical lens has to be disconnected before the surface damage effect of the sensor can be detected. In this work, a novel surface damage effect detection algorithm of sensor in optical lens based on cat-eye effect is proposed. As the damage regions of the sensor can be regarded as some anomalistic aperture diaphragms, the reflectivity model of the sensor can be established, where the optical path of the surface damage detection system can be taken as a propagate process for a plane wave through a defocused optical lens and is reflected back to the return place. Based on the theory of angular spectrum diffraction, the diffraction transmission formulas for a plane wave through the cat-eye system are derived by taking two-dimensional discrete Fourier transfer. Afterwards the regulations on the variation of the intensity distribution of the cat-eye reflected light with some different damage conditions of the sensor are given and then the effect of the focal shift is analyzed. Experiment results show the intensity distribution of the cat-eye reflected light has direct relationship with the profile of the damage region and the amplificatory effect for the small damage region is of direct ratio with the focal shift. Moreove, the proposed method can be straightforwardly utilized for the surface damage effect detection of the sensor in optical lens without disconnecting it. |
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