Micro-miniature accelerometer
US4736629A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 20, 1985 |
| Grant date | Apr 12, 1988 |
| Priority date | — |
| Expiry date | Dec 20, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P2015/0831
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The accelerometer comprises a substrate (52), a metallic movable plate (50), and a mounting system (54) for mounting the movable plate such that it is positioned above the substrate and can rotate about a flexure axis (64) that is above and is substantially parallel to the substrate. The flexure axis divides the sensing element into first (66) and second (68) sections. The total moments of the first and second sections about the flexure axis are different, such that acceleration normal to the substrate tends to rotate the sensing element about the flexure axis. A first electrode (74) is mounted by the substrate adjacent the first section to form a first capacitor (C.sub.A), and a second electrode (76) is mounted by the substrate adjacent the second section to form a second capacitor (C.sub.B). A detector for measuring the relative capacitances of the first and second capacitors is provided comprising an integrator (166), an inverting amplifier (168), and switches (160, 162, 164) for periodically charging and discharging the capacitors in response to a clock signal. In one embodiment, the sensing element includes an internal opening (16, 56, 126) and the mounting system is positione…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.