Guarded Capacity Proximity Sensor with One-Dimension Differentiation

• Main Authors: Shih-hong Liou, 劉士弘
• Other Authors: Jang-Zern Tsai
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/99102140430024645024

碩士 === 國立中央大學 === 電機工程研究所 === 97 === Capacitive proximity sensor offers the advantage that allows the relatively large sensing area with the same size of the single sensor. So it is difficult to detect position of the object with single sensor. The capacitive proximity sensor usually detects the character of the object like different thickness and different dielectric. It is also can detect proximity of the object. In this paper, we proposed and demonstrated a guarded capacitive proximity sensor with one-dimensional differentiation which includes a differential mode and a summation mode. The sensing probe uses two sensor planes to facilitate the differential mode to indicate relative location of the object on the sensor plane. The two sensor planes can be used as a sensing element to facilitate the summation mode to sense the property or the distance of the object. The two modes combined enable the one-dimensional differentiation. This sensor improves its sensing ability by incorporating a capaciflector to restrain stray capacity. The sensor can be used to detect either the one-dimensional position or the thickness of a target object.