Patent ID: 7397172

Claim:
A piezoelectric resonator element, comprising: a base made of a piezoelectric material; at least a pair of resonating arms provided in a unified manner with the base and extending in parallel with each other from the base; a portion defining a long groove provided to each of the resonating arms along a longitudinal direction; a driving electrode provided to the long groove; wherein each of the resonating arms includes a structure to adjust hardness balance between right and left structures with respect to a virtual central line extending in the longitudinal direction; and wherein a right constricted portion and a left constricted portion with respect to the virtual central line are provided to a base portion of each of the resonating arms so as to make a width of the resonating arms large on the base side and make the width sharply reduce toward each end portion, and the right constricted portion is made larger than the left constricted portion as the structure to adjust.