雷射掃瞄一維表面形貌之研究

Study on the laser scanning profilometer

林彥廷(Yen-Ting Lin)

指導教授 ： 邱銘宏

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2010年)

摘要

本論文主要研究是利用臨界角的特性，來進行一維掃描物體表面的高度差或位移量。此原理乃利用幾何光學光追跡法原理決定光線高度與其角度。若以一平行於光軸之光線入射一透鏡，經待測面反射後返回此透鏡，當待測面有位移現象或高低落差時，即當反射偏離透鏡焦平面時，此時光反射回透鏡後，光路會呈現偏離光軸的現象，而進入一稜鏡後，利用臨界角的特性，入射光偏離或接近臨界角時，稜鏡之反射光強度會有所改變；因此，藉由光強度的不同來計算出位移量或分析出物體表面的高低差，整個過程以掃描方式測出物體表面高低，並繪圖顯示結果。預計測量最小單位為1μm，最大位移量可大於±50μm。

關鍵字

臨界角

並列摘要

The thesis is based on the characteristics of the critical angle to carry out the laser scanning profile, the height difference or displacement. During the experiment, at first, the angle of reflection light from the test surface is calculated using the principle of geometric optics. A beam parallel to the optic axis passes through a lens with a height, and then it is focused on the test surface. If the test surface deviates from the focal plane and the reflected light is back to the lens, the angle of out going will be changed. Based on the critical angle characteristic, the deviation angle of the light causes the reflectance vary suddenly, thus, we should use a prism as an angular sensor to detect the reflectance at the critical angle nearby, the deviation angle is calculated. Therefore, we could calculate the defocus length or to analyze the surface profile using the change of the reflectance. Scanning the target, the surface profile is obtained. From our results, the precision of displacement is 1μm, and the maximum displacement can be greater than ± 50μm.

並列關鍵字

critical angle

參考文獻

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