Patent ID: 8056414
Filing Date: 2011-11-15
Classification: G01C

Abstract:
1. An angular velocity sensor comprising: a fixed portion fixed to a support surface, a detection arm portion connected to the fixed portion and extending along a plane parallel to the support surface, and a drive arm portion connected to the fixed portion and extending along the plane parallel to the support surface, wherein the fixed portion includes two slits or trenches extending at least in a direction intersecting with an extending direction of the detection arm portion, the detection arm portion includes a first upper vibration arm and a first lower vibration arm respectively connected to the fixed portion on sides opposite to each other, the drive arm portion includes a second upper vibration arm and a third upper vibration arm connected to the fixed portion on one side in such a manner as to form a pair of arms, with the first upper vibration arm in between, and respectively extending along the plane parallel to the support surface in a same direction where the first upper vibration arm extends, connection points, where the fixed portion is connected to each of the first to third upper vibration arms, are linearly arranged in a straight line on one side of the fixed portion, each slit or trench is configured in the form of a consecutive U-shape and open sides of the U-shape are arranged toward a center of gravity of the angular velocity sensor, the two slits or trenches are arranged to face each other in the extending direction of the detection arm portion with the center of gravity in between and arranged symmetrically with respect to the detection arm portion, and when a length of the slit in a direction orthogonal to the extended direction of the detection arm portion or the first vibration arm is defined as x and a length of the fixed portion in the direction orthogonal to the extended direction of the detection arm portion or the first vibration arm is defined as W, the x and the W satisfy a relational expression of x/W>0.5.