本論文提出一套新的二維量測系統-「2D疊紋量測系統」，利用兩個線性光柵，配合光學系統以及待測物反射光的特性，得到其疊紋圖案。因其待測物位置的不同，得到的疊紋圖案也不同，因而藉由此現象，開發出一套2D疊紋量測系統。 疊紋現象是指兩個周期相近的光柵，所組成的低頻圖案。本論文研究方法如下:以一道準直雷射光通過第一道光柵，經由物鏡聚焦在待測物上，經由待測物反射後，回到其光學系統中，再通過第二道光柵形成疊紋。由於待測物位置不同，對焦、離焦、近焦三種位置，可產生不同的斜率的疊紋圖案。如此可藉由此現象，搭配疊紋判讀技術，以及兩個馬達的配合，逐步整個待測物，可得到其二維表面的三維圖。 根據實驗結果，其厚度的量測，在固定的物鏡情況下，光柵0.2mm時，工作距離內其靈敏度為約1.6(mm-1)，而光柵0.3mm時，工作距離內其靈敏度為約1.1(mm-1)。其長度的量測中，馬達的步數越小，取的數值越多，可以得到更精確的數值，使用者可依據不同的需求，來選擇所需要的規格與參數。 本系統利用疊紋方法，藉由差動訊號，並配合馬達，做出二維表面起伏的三維圖。於2D缺陷與尺寸與3D形貌量測技術的領域上，將是一套具有相當潛力的量測系統。 In this paper, a new two-dimensional measurement system which we call the 2D scanning system by using moir? have been presented. It uses two linear gratings、optical system、and the reflected light from the sample to get the moir? pattern. The different moir? patterns come from the different distances of the sample. We use that characteristic to develop the 2D scanning system. The moir? pattern refers to geometrical interference fringes, and is formed by two gratings that lie in contact, with small angle between two linear gratings. As a result, when a collimation laser goes through the first linear grating, it will be reflect by the sample. When it comes back to the optical system again, it will go through the second linear grating and become the moir? pattern. There are three kind of distance:focus、far focus、and near focus. They will decide the slope of moir? pattern. We use that characteristic to develop the moir? detect system. We combine the moir? detect system and two motors to scan the sample, and will get the three-dimensional pattern about two-dimensional surface. We control the experimental environment in the same objective. According to the experimental data, the sensitivity is 1.6(mm-1) when the grating pitch is 0.2mm in the work distance The sensitivity is 1.1(mm-1) when the grating pitch is 0.3mm in the work distance. The motor step distance is smaller, the experimental data will be more. We also can get more accurate datas. The users can decide the experimental specifications and parameters according to what you need. This system combines the moir? effect, differential signal and the motors to make the three-dimensional pattern about two-dimensional surface pattern. This system has great potential in defects and size of 2D and 3D measurement technique.
