PIEZOELECTRIC VIBRATION PIECE, PIEZOELECTRIC VIBRATOR, OSCILLATOR, ELECTRONIC APPARATUS AND RADIO-CONTROLLED CLOCK

摘要

PROBLEM TO BE SOLVED: To provide a piezoelectric vibration piece which is capable of reducing a CI value while preventing rigidity reduction in a vibration arm part, improves vibration characteristics and impact resistance and can be small-sized.SOLUTION: A piezoelectric vibration piece 5 is provided which comprises: a pair of vibration arm parts 20, 21 disposed in parallel with each other while interposing a central axis O1 therebetween; and a base part 22 which integrally cantilever-supports proximal end portions of the pair of vibration arm parts in a length direction M1. On principal surfaces of the pair of vibration arm parts, a first groove portion 28 which is disposed at a distal end side of the vibration arm part in the length direction and has a groove width W1 along a width direction M3 orthogonal to the length direction and a thickness direction M2 of the vibration arm part, and a second groove portion 29 disposed closer to the proximal end portion than the first groove portion and having a groove width W2 along the width direction are formed, and a value (groove width W2 of second groove portion/groove width W1 of first groove portion) is set to 0.4 or more and less than 1.0.