Patent ID: 6828806
Filing Date: 2004-12-07
Classification: G01D,H03K

Abstract:
An electrostatic capacitance sensor, comprisingan electrostatic capacitance detector, an operational amplifier in which a feedback impedance circuit is connected between an output terminal and an inverse input terminal of said operational amplifier, a signal line connected between said inverse input terminal of said operational amplifier and said electrostatic capacitance detector, an alternating-current signal generator connected to a non-inverse input terminal of said operational amplifier, and a shield for shielding at least a portion of said signal line, said shield being connected to said non-inverse input terminal of said operational amplifier and said alternating-current signal generator, wherein said electrostatic capacitance detector comprises a detecting electrode and a shield electrode, said detecting electrode comprises a detecting portion for detecting an object to be detected and an introducing portion for introducing an electrode to said detecting portion, said shield electrode is connected to said shield, and at least a portion of said introducing portion of said detecting electrode is shielded by said shield electrode.