CAPACITIVE SENSOR

• Main Author: SHIRAI MASARU
• Format: Patent
• Language: English; Japanese
• Published: 01.03.2018
• Subjects: MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To provide a capacitive sensor with which it is possible to suppress an output change caused by leakage.SOLUTION: A capacitive sensor 1 comprises a sensor circuit 30 including a first capacitor 31 and a second capacitor 32, a CV conversion circuit 40 and a control circuit. The control circuit switches the connection state of the first capacitor 31 and second capacitor 32 with the CV conversion circuit 40 between first to three connection states. In the first connection state, the two capacitors 31, 32 are connected, a potential between the two capacitors 31, 32 is set to a prescribed potential, and electrical continuity between the two capacitors 31, 32 and the CV conversion circuit 40 is cut off. In the second connection state, the two capacitors 31, 32 are connected, the setting of a potential between the two capacitors 31, 32 is cleared, and electrical continuity between the two capacitors 31, 32 and the CV conversion circuit 40 is cut off. In the third connection state, electrical continuity between the two capacitors 31, 32 is cut off and the second capacitor 32 and the CV conversion circuit 40 are connected.SELECTED DRAWING: Figure 5 【課題】リークに起因する出力変化を抑制できる静電容量センサを提供する。【解決手段】静電容量センサ１は、第１コンデンサ３１と第２コンデンサ３２とを含むセンサ回路３０と、ＣＶ変換回路４０と、制御回路とを備える。制御回路は、第１コンデンサ３１と第２コンデンサ３２とＣＶ変換回路４０との接続状態を第１〜第３接続状態の間を切り替える。第１接続状態では、両コンデンサ３１，３２が接続され、両コンデンサ３１，３２間の電位が規定電位に設定され、かつ両コンデンサ３１，３２とＣＶ変換回路４０との間の導通が遮断される。第２接続状態では、両コンデンサ３１，３２が接続され、両コンデンサ３１，３２間の電位の設定が解除され、かつ両コンデンサ３１，３２とＣＶ変換回路４０との間の導通が遮断される。第３接続状態では、両コンデンサ３１，３２間の導通が遮断されて、第２コンデンサ３２とＣＶ変換回路４０とが接続される。【選択図】図５