The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 16, 2019
Filed:
Apr. 06, 2016
Murata Manufacturing Co., Ltd., Kyoto, JP;
Masaaki Takata, Kyoto, JP;
MURATA MANUFACTURING CO., LTD., Kyoto, JP;
Abstract
An amplifier circuit converts a charge signal into a voltage signal. The charge signal indicates a detection result outputted from a piezoelectric device that detects a detection object as a change in an amount of a charge. The charge signal includes a displacement signal in a predetermined frequency band. The amplifier circuit includes an operational amplifier including an inverting input terminal receiving the charge signal and an output terminal for outputting the voltage signal, a resistor electrically connected between the inverting input terminal and the output terminal, and a capacitor connected in parallel with the resistor. A resistance value of the resistor and a capacitance value of the capacitor are set such that, in the frequency band of the displacement signal, an absolute value of an impedance of the resistor is lower than an absolute value of an impedance of the capacitor.