ACCELERATION SENSOR, GEOPHONE AND SEISMIC SURVEY SYSTEM

摘要

Provided are an acceleration sensor, a geophone and a seismic survey system which have high sensitivity and low power consumption. The acceleration sensor is provided with a mass body 11 which can be displaced relative to a rotating shaft 14. The mass body 11 includes a first movable portion 21 and a second movable portion 22 having a greater surface area than the first movable portion 21. The acceleration sensor includes a first AC servo control electrode 33 disposed facing a first symmetrical region 23 of the first movable portion 21, a second AC servo control electrode 34 disposed facing a second symmetrical region 24 of the second movable portion 22, and a DC servo control electrode 35 disposed facing an asymmetrical region 25 of the second movable portion 22. Furthermore, a first AC servo capacitative element (43) is formed from the first movable portion 21 and the first AC servo control electrode 33, a second AC servo capacitative element (44) is formed from the second movable portion 22 and the second AC servo control electrode 34, and a DC servo capacitative element 45 is formed from the second movable portion 22 and the DC servo control electrode 35.