Capacitive physical quantity detection device
US6450029B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 2000 |
| Grant date | Sep 17, 2002 |
| Priority date | — |
| Expiry date | Mar 21, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P2015/0814
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A capacitive semiconductor acceleration sensor capable of efficiently performing a self-diagnostic procedure without having to provide any separate electrodes for self-diagnosis purposes. The acceleration sensor includes a beam portion that is deformable upon application of acceleration thereto in a direction at right angles to the elongate direction thereof to thereby exhibit a spring function. The sensor also includes a movable electrode and fixed electrodes which are integrally formed with the beam portion. The sensor is operable to detect the acceleration while applying between the movable electrode and fixed electrodes a periodically changeable signal to derive an output voltage variable in potential with a differential capacitance change of capacitors between the both electrodes. Here, a detection signal for detection of such acceleration and a self-diagnosis signal are selectively applied while permitting creation of quasi-acceleration at the movable electrode due to application of the self-diagnosis signal, wherein a ratio of a frequency of the self-diagnosis signal to a resonance frequency of the beam portion in its deformation direction is set so that the resultant resona…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.