Patent ID: 7071794

Claim:
A quartz crystal resonator capable of vibrating in a flexural mode of an inverse phase, the quartz crystal resonator comprising: a quartz crystal tuning fork base; first and second quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, each of the first and second quartz crystal tuning fork tines having a first main surface and a second main surface opposite the first main surface and a groove having a plurality of stepped portions formed in at least one of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; and an electrode disposed in the groove formed in at least one of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines so that a merit value M 1 of a fundamental mode of vibration of the quartz crystal tuning fork resonator is greater than a merit value M 2 of a second overtone mode of vibration thereof, the merit values M 1 and M 2 being defined by the ratios Q 1 /r 1 and Q 2 /r 2 , respectively, where Q 1 and Q 2 represent a quality factor of the fundamental mode of vibration and the second overtone mode of vibration, respectively, of the quartz crystal tuning fork resonator and r 1 and r 2 represent a capacitance ratio of the fundamental mode of vibration and the second overtone mode of vibration, respectively, of the quartz crystal tuning fork resonator; wherein a piezoelectric constant e 12 of the quartz crystal tuning fork resonator is within a range of 0.095 C/m 2 to 0.19 C/m 2 in the absolute value.