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:
Dec. 29, 2015
Filed:
Aug. 07, 2012
Akira Kumada, Nagaokakyo, JP;
Teruhisa Shibahara, Nagaokakyo, JP;
Kenji Tanaka, Nagaokakyo, JP;
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
A variable capacitance device that achieves a desired capacitance even when factors causing varied capacitances are generated is configured such that a capacitance detection pulse signal is applied from a capacitance detection signal generation unit to a driving capacitor and a reference capacitor of a MEMS mechanical unit. The device voltage of the driving capacitor based on the capacitance detection signal and a driving voltage is applied to the inverting input terminal of a comparator. The device voltage of the reference capacitor based on the capacitance detection signal and the driving voltage is applied to the non-inverting input terminal of the comparator. The comparator generates a comparison output signal including 'Hi' and 'Low' values from the difference between these device voltages, and applies the output signal to a driving voltage generation unit. The driving voltage generation unit increases or decreases the driving voltage based on the comparison output signal.