field scan的用法和樣例：
例句
- In scanning, the technique of using more than one vertical scan to reproduce a complete image. In television, 2:1 interlace is used, giving two vertical scans(fields) per frame; one field scans odd lines, and one field scans the even lines of the frame.
利用多次垂直掃描來重顯一幅完整圖象的掃描技術。電視中使用2：1的交錯率，即每幀分兩場，垂直掃描兩次，一場掃描奇數行，另一場掃描偶數行。
