ANGULAR ACCELERATION DETECTOR.

摘要

An angular acceleration detector (10) is provided with two slit-carrying discs (14, 15) mounted fixedly and coaxially in an opposed state on a rotary body (13), and a semiconductor position detecting unit (19) formed as a detecting means and consisting of a light emitting element (20) and a semiconductor position detecting member (21) which are disposed in an opposed state across the slits in these discs, the angular acceleration of the rotary body being detected by using this detecting unit. The slits (17) in the disc (15) cross at a predetermined angle the slits (16) in the disc (14). The disc (15) has an annular weight portion (15b) at the radially outer side of a slit-formed portion thereof, and a resiliently deformable spring portion (15c) circumferentially arranged at the inner side of the weight portion. The angular acceleration of the rotary body can be measured by detecting the movement of the crossing portions of the slits relatively moving due to the inertial force of the weight portion.