本研究中應用雷射二極體和發光二極體作為光源，經光學系統成像於CMOS影像感測器上，擷取光點影像之後分析光點位置以推算待測系統之成像條件，並推算得欲測量之物理量，如距離、角度或水平傾角等等。 光電式水平儀使光源經過一組特殊設計之透鏡組，會聚光束並穿透液體後聚焦於互補性氧化金屬半導體影像感測器上。當系統傾斜時因液體也隨之傾斜而將光線會聚至其它位置，產生了成像光點之位移。推算此位移量即可計算得知系統之傾斜角度，精準度可達10秒角。另一設計係使用雷射二極體經透鏡會聚光束，照射液面反射至影像感測器上，當系統傾斜時光點位置產生位移，由於光槓桿原理可使感測精度達1秒角。以上二者皆具有靈敏度高、機構簡單、成本低且安裝容易的優點。 In this case we used laser diode and light emitter diode as light source of measurement systems. The light source will be focused on CMOS image sensor by the lens system and tilt angle will be measured by read the centriod position of light spot. We designed two tilt angle measurement systems which can be used to calibrate the level. The refraction leveler reached 10 sec of arc accuracy and the reflection leveler reached 1 sec of arc accuracy. By centriod method we can get the light spot position in subpixel accuracy. The method is high sensitive and simple to be calculated. The adventures of these two systems with simple structure are inexpensive and can be easily set.
