| 摘要 |
A three-axis acceleration sensor having a simple construction is provided for improving shock resistance without lowering sensor sensitivity. An acceleration sensor for detecting acceleration in three orthogonal directions comprises an electrode substrate pair including electrode substrates (4) opposed to each other, and each having fixed electrodes (4c, 4b, 4a) corresponding to three axes, respectively, a diaphragm (2) acting as a movable electrode, and an umbrella-like weight (3) mounted centrally of the diaphragm (2). Acceleration is detected based on variations in capacitance between the fixed electrodes (4c, 4b, 4a) and diaphragm (2). Each electrode substrate (4) has an electret layer (1) formed to cover surfaces of the fixed electrodes (4c, 4b, 4a). At least one of the electrode substrates defines, centrally thereof, a through hole (7). A shaft portion of the umbrella-like weight (3) extends through the through hole (7) from outside, and is connected to the diaphragm (2). |
