Position detector

Abstract

Abstract PURPOSE:To obtain a high-accuracy detector with superior linearity by superposing a triangular wave on two kinds of rectangular waves which differ in polarity and impressing two kinds of reference signals to two reference signal electrodes, and detecting variation in the electrostatic capacity between said electrodes and a detection signal electrode. CONSTITUTION:A reference signal generating circuit 11 superposes the triangular wave phi3 upon the rectangular waves phi1 and phi2 which differ in polarity to generate reference signals phi1+phi3 and phi2+phi3, which are impressed to the electrodes 26 and 27 respectively. Then, the electrostatic capacity between the electrodes is varied interlockingly with the displacement of a body to be detected, and a signal is detected by the electrode 28 provided opposite the electrodes 26 and 27. At this time, components of the rectangular waves phi1 and phi2 remain corresponding to the difference in opposition area between the electrode 28 and electrodes 26 and 27, and the signal generated by superposing the triangular wave phi3 thereupon is detected 28. Then this signal is inputted to a comparator circuit 41 and compared with a set value. At this time, the rectangular wave components are superposed upon the triangular wave phi3 in a balanced signal to remain and then the level increases or decreases, so that the period of the variation of the output of the circuit 41 varies. Namely, a phase information converting circuit 51 outputs a corresponding position electrically by the phase variation of the circuit 41.

Inventors

• 👤 Takaichi Maruyama
• 👤 丸山　貴市
• 👤 Osamu Watanabe
• 👤 修 渡辺
• 👤 Tomoo Fujimori
• 👤 知雄 藤森
• 👤 Shinji Iwanami
• 👤 岩波　新二
• 👤 Norikazu Yamaguchi
• 👤 山口　典一

Bibliographic Details