Title:
ELECTRIC POTENTIAL SENSOR AND ELECTRONIC DEVICE USING IT
Document Type and Number:
Japanese Patent JP3555518
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an electric potential sensor wherein the output signal is relatively stable even when the oscillation of in-phase mode is applies to a piezoelectric tuning fork under external factor.
SOLUTION: One arm 3 of a piezoelectric tuning fork 21 is provided with, facing a surface 8 which is to be detected, a detection electrode 7, a driving piezoelectric body 22, and a feedback piezoelectric body 24, while the other arm 4 is provided with a driving piezoelectric body 23 and a feedback piezoelectric 25. A detection circuit 12 is provided wherein the signal outputted from the detection electrode 7 is synchronized for detection with the signal wherein the signals outputted from two feedback piezoelectric bodies 24 and 25 are added together by an adder 26. Thus, even if the piezoelectric tuning fork is applied with the oscillation of in-phase mode under an external factor, the output signal is stable.
Inventors:
Kyoji Horiguchi
Application Number:
JP26237899A
Publication Date:
August 18, 2004
Filing Date:
September 16, 1999
Export Citation:
Assignee:
MURATA MANUFACTURING CO.,LTD.
International Classes:
G01R29/12; G01R29/24; H01L41/113; (IPC1-7): G01R29/12
Domestic Patent References:
| JP10339754A |