A vibration element includes a crystal blank, a pair of excitation electrodes, and pair of extraction electrodes. The crystal blank is an AT cut crystal blank including a mesa part and an outer circumferential part which is thinner than the mesa part and surrounds the mesa part. The pair of excitation electrodes is provided on the two major surfaces of the mesa part. The pair of extraction electrodes include pad parts which are provided at the end parts of the crystal blank in the longitudinal direction on one major surface of the outer circumferential part and are connected to the pair of excitation electrodes. The length in the longitudinal direction of the crystal blank is less than 1000 m. When the resonance frequency is F (MHz) and t=1670/F, the distance y (m) between each of the pad parts and the mesa part satisfies 0.048F+1.18<y/t<0.097F+0.36.

An oven controlled crystal oscillator includes a crystal oscillator, a temperature control circuit, and a control integrated circuit. The crystal oscillator includes a crystal resonator and an oscillator circuit. The temperature control circuit includes a heater resistor, a thermistor, a first resistor, a second resistor, a third resistor, a differential amplifier, a thermosensor, and a fourth resistor. The thermosensor is disposed in parallel to the first resistor. The thermosensor has one end to which the supply voltage is supplied. The fourth resistor has one end connected to another end of the thermosensor and another end that is grounded. The control integrated circuit includes a digital variable resistor and a controller. The digital variable resistor is connected to the thermosensor in parallel. The controller adjusts a resistance value of the digital variable resistor based on a digital control signal input from outside.

A crystal oscillator device is disclosed. The crystal oscillator device includes a crystal piece provided in a casing; a pair of excitation electrodes provided for the crystal piece; a coil provided on the crystal piece; a magnetic flux generating member configured to generate magnetic flux passing through the coil; and an alarm generator configured to generate an alarm based on a signal whose amplitude is equal to or less than a reference value, the signal being generated in the coil.

A crystal unit includes a package, a crystal element, and a temperature sensor. The crystal element includes a crystal blank and a pair of excitation electrodes on a pair of major surfaces of the crystal blank and is air-tightly sealed in the package. The temperature sensor is mounted in the package. The crystal blank includes a crystal plane inclined relative to the major surfaces in at least a portion of the side surfaces.

A crystal unit includes an AT-cut crystal element that has a planar shape in a rectangular shape and a part as a thick portion. The crystal element includes a first end portion, a first depressed portion, the thick portion, a second depressed portion, and a second end portion in an order from a side of one short side in viewing a cross section taken along a longitudinal direction near a center of the short side. The first depressed portion is a depressed portion disposed from the thick portion toward the first end portion side, depressed with a predetermined angle a and subsequently bulged, and connected to the first end portion. The second depressed portion is a depressed portion disposed from the thick portion toward the second end portion side, depressed with a predetermined angle b and subsequently bulged, and connected to the second end portion.

A circuit device includes a digital interface, a processor, an oscillation signal generation circuit, a clock signal generation circuit that generates a clock signal having frequency obtained through multiplication of a frequency of the oscillation signal, and terminal groups of the digital interface and the clock signal generation circuit. The terminal group of the digital interface is disposed in a first region along a first side of the circuit device, and the terminal group of the clock signal generation circuit is disposed in any one of second, third and fourth regions of the circuit device.

An oscillator including a container, a first protrusion portion protruding from the container along a first direction, a second protrusion portion protruding from the container along the first direction, and a projection portion protruding from the container along the first direction. The second protrusion portion is shorter than the first protrusion portion in the first direction, and the projection portion is longer than the second protrusion portion and shorter than the first protrusion portion in the first direction.

A piezoelectric oscillator includes a base member on which a piezoelectric resonator is mounted, a first lid member that seals the piezoelectric resonator on the base member, and a second lid member that seals the first lid member on the base member. The first lid member and the second lid member are each joined to the base member.

An oscillator includes a resonator element provided with an excitation electrode, an oscillation circuit for oscillating the resonator element to generate an oscillation signal, a temperature sensor for generating a temperature signal for temperature compensation of the oscillation signal, a temperature control element for controlling temperature of the resonator element, and a container that houses the resonator element, the oscillation circuit, the temperature sensor, and the temperature control element, in which the temperature sensor and the temperature control element overlap the excitation electrode in plan view.

An oscillator including a container, a first protrusion portion protruding from the container along a first direction, a second protrusion portion protruding from the container along the first direction, and a projection portion protruding from the container along the first direction. The second protrusion portion is shorter than the first protrusion portion in the first direction, and the projection portion is longer than the second protrusion portion and shorter than the first protrusion portion in the first direction.