光學尺解析刻度細分割方法與實現

　　　　　光學尺在現今精密機械車床上使用廣泛，唯精密度高的光學尺，其光柵間距愈 小製造愈難，相對價格愈高，如何運用電子技術有效的提高光學尺的解析度，排除機械製作 上的困難，是目前業界尋求研究解決的課題。本文提出即時地指示光學尺在左、右位移第一 刻度的判斷方法，及解析刻度細分割方法，將一個刻度信號，可選擇地分割為 2、4、8、16 、32 倍解析度。依所提理論方法，以純硬體電路完成，可即時地指示光學尺位移方向，並 提高其解析度。經實際電路證明，確實可提升光學尺的解析度，供產業界實際應用。
　　　　　Linear scale has been widely adopted in the modern applications of mechanical lathe with high precision. However, expensive cost and the requirement with high precision for linear scale are still the main problems to be solved. Thus, the problem how to overcome the difficulties caused by high precision requirement encountering in mechanical manufacturing is an important research topic in improving the precision of linear scale. In this paper, we propose a method to judge the scaling movement of on unit in calibration when the linear scale shifts in left or right direction. In addition, a resolution division method which can optionally divide the calibration signal of scale grating into 2, 4, 8, 16 and 32 times the resolution is also provided. Based upon the proposed methods, the experimental results show that the resolution of linear scale can be improved significantly and thus the methods we described are effective for industry applications with high precision requirement.