| 摘要 |
Method and apparatus for sensing the displacements of micromachined devices and sensors. The method is referred to as the enhanced modulated integrative differential optical sensing (EMIDOS). The target micromachined proof-mass, for which displacements are measured, includes a grid of slits. The micromachined device is bonded to a CMOS chip containing a matching photodiodes array and their readout electronics. The grid is aligned with the photociiodes. An illumination source, such as an LED, is then mounted above the micromachined device. A model for the noise equivalent displacement (NED), including mechanical, electrical and optical domains, as well as all noise sources is derived. The model predicts that displacements below 10<SUP>-3 </SUP>[√{square root over (Hz] can be measured. The design comprises innovative inertial sensors, an accelerometer and a rategyroscope employing the EMIDOS. Performance models for the noise equivalent acceleration (NEA) and noise equivalent rate (NER) are also derived. The models show that an accelerometer with a very low NEA can be realized. |
