Patent ID: 7170218

Claim:
An electronic apparatus comprising: a display portion; and first and second quartz crystal oscillators comprised of first and second quartz crystal oscillating circuits each having a quartz crystal resonator, an amplifier, a plurality of resistors, and a plurality of capacitors, a mode of vibration of the quartz crystal resonator of the first quartz crystal oscillating circuit being different from that of the quartz crystal resonator of the second quartz crystal oscillating circuit; wherein the quartz crystal resonator of one of the first and second quartz crystal oscillating circuits comprises a quartz crystal tuning fork resonator capable of vibrating in a flexural mode of an inverse phase and having a fundamental mode of vibration and a second overtone mode of vibration, the quartz crystal tuning fork resonator being electrically connected to an amplification circuit having an amplifier and a feedback resistor and to a plurality of capacitors and a drain resistor of a feedback circuit having the quartz crystal tuning fork resonator, and the quartz crystal tuning fork resonator having a quartz crystal tuning fork base, a plurality of quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, the quartz crystal tuning fork tines having a first quartz crystal tuning fork tine and a second quartz crystal tuning fork tine, 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 at least one groove having 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; wherein a merit value M 1 of the fundamental mode of vibration of the quartz crystal tuning fork resonator is greater than a merit value M 2 of the 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; and wherein a ratio of an absolute value of negative resistance −RL 1 of the fundamental mode of vibration of the amplification circuit and a series resistance R 1 of the fundamental mode of vibration is greater than that of an absolute value of negative resistance −RL 2 of the second overtone mode of vibration of the amplification circuit and a series resistance R 2 of the second overtone mode of vibration.