Finnegan, Henderson, Farabow, Garrett & Dunner
Integration circuit
 An integration circuit comprises an operational amplifier with first and second input terminals and an output terminal, an integration capacitor connected between the first input terminal and the output terminal, an integration resistor connected at one end to the first input terminal, a switch connected at one end to the other end of said resistor, a voltage signal source to be integrated which is connected through the switch to the other end of the resistor, and a reference voltage signal source connected to the second input terminal. The integration circuit further comprises means which applies, at the same time as the switch is opened, a signal with the same potential as the signal derived from the reference voltage signal source to said other end of the resistor, thereby to prevent an output signal from being adversely affected by a parasitic capacitance of the switch. An integration method includes a first step for applying a voltage signal to be integrated to an input part of an integration circuit and a second step for stopping the application of the integration voltage signal to the input part, and further comprises a third step for applying a reference potential signal to the input part of the integration circuit at the same time as the voltage signal to be integrated stops. 
Tokyo Shibaura Denki Kabushiki Kaisha
G
G06G
inventional
Chikara Yasoji Eiji
Sato Suzuki Masuda