To provide an inertia sensor provided with a beam compatible in both high sensitivity and impact resistance.
Easily deformable parts (thin thickness of recesses 15, holes or the like) are provided locally while avoiding a portion concentrated with a stress generated in the beam by impact. The recesses 15 are arranged line-symmetrically with respect to a straight line along an extension direction passing the center of the beam 13, and a straight line right-angled to the extension direction. A root part of the beam 13 is formed to form a gentle angle making the root part not contact with a weight 12 and a frame 14 at right angle. The sensitivity of the sensor is enhanced thereby without lowering the impact resistance of the sensor, and a stress concentrating area in the beam root part is dispersed to enhance the impact resistance without sacrificing the sensitivity of the sensor.
NAKAMURA YOSHITAKA
TOKUNAGA HIROSHI
NAGATA KENJI
FUJITSU LTD