| 摘要 |
PURPOSE:To prevent clogging due to dust and to obtain a high-performance acoustic gyroscope by opening adjusting small holes at a part facing a substrate, and covering the outside of the substrate with a cover for protecting electronic parts. CONSTITUTION:Adjusting small holes 20, 20' and 20'' avoid a part of a detecting duct 17. The small holes are opened at a part where a substrate 16 faces a chamber 111. A cover 15 for protecting electronic parts on the substrate is attached to a case 11 at the four corners so as to hold the substrate 16. Therefore, the adjusting small holes 20, 20' and 20'' are communicated to the space in the chamber 111 and the inside of the cover 15. The time constant formed of the volume of the space in the inside of the cover 15 and the acoustic resistances of the small holes 20, 20' and 20'' is sufficiently larger than the inverse number of the driving frequency, i.e. the driving period, due to an acoustic speaker. Therefore, the adjusting actions of the small holes 20, 20' and 20'' are hardly changed from the case wherein the small holes are directly communicated to outer air. Meanwhile, since dust at the outside does not intrude into the inside, the small holes 20, 20' and 20'' are not clogged. |
