PURPOSE: To prevent noise from occurring due to a pyroelectric effect, etc. by providing a compensating piezoelectric body made of the same material and having the same thickness as a film piezoelectric body for detecting acceleration in the vicinity of a detector.
CONSTITUTION: A film piezoelectric body 13 and a load 14 are laminated on a seat 11 to constitute a sensor A. The load 14 functions as an inertial mass part and, with acceleration applied, generates strain on the film piezoelectric body 13. A compensating piezoelectric body 15 made of a film piezoelectric body having the same thickness as the film piezoelectric body 13 is adhered to a side of the film piezoelectric body 13 of the sensor A on the upper face of the seat 11 so that a differential output of both piezoelectric bodies 13, 15 can be taken outside. Thus voltage generated due to a pyroelectric effect and other common mode noise can be eliminated.
NAKAYAMA SHIRO
KUNIMURA SATOSHI
TAKAHASHI KATSUHIKO
