A vibration element includes a base and a vibrating arm extending from the base. The vibrating arm includes an arm positioned between the base and a weight. A weight film is disposed on the weight. The weight has a first principal surface and a second principal surface in a front and back relationship with respect to a center plane of the arm. A center of gravity of the weight is located between the first principal surface and the center plane of the arm. A center of gravity of the weight film is located between the second principal surface and the center plane of the arm.

An electrical field detector includes an electromechanical oscillator, part of which is included of a piezoelectric element, a frequency measuring device which is coupled to the oscillator so as to measure the oscillation frequency, and an electrical masking assembly. The electrical masking assembly is arranged close to the piezoelectric element so that, during an use of the detector, the piezoelectric element moves by vibrating relative to the electrical masking assembly. A variable part of the piezoelectric element is thus exposed to the electrical field to be measured. A change in the oscillating frequency then forms an electrical field measurement result.

A resonant member of a MEMS resonator oscillates in a mechanical resonance mode that produces non-uniform regional stresses such that a first level of mechanical stress in a first region of the resonant member is higher than a second level of mechanical stress in a second region of the resonant member. A plurality of openings within a surface of the resonant member are disposed more densely within the first region than the second region and at least partly filled with a compensating material that reduces temperature dependence of the resonant frequency corresponding to the mechanical resonance mode.

A resonant member of a MEMS resonator oscillates in a mechanical resonance mode that produces non-uniform regional stresses such that a first level of mechanical stress in a first region of the resonant member is higher than a second level of mechanical stress in a second region of the resonant member. A plurality of openings within a surface of the resonant member are disposed more densely within the first region than the second region and at least partly filled with a compensating material that reduces temperature dependence of the resonant frequency corresponding to the mechanical resonance mode.

A tuning fork-type vibration piece is provided, in which a cushioning portion is formed on the base of a package and allowed to contact parts for contact of arm portions which are any parts but their edges, and the parts for contact of the arm portions that contact the cushioning portion are electrodeless regions, which prevents the risk of frequency fluctuations caused by any electrode being chipped off by contact with the cushioning portion.

A tuning fork-type vibration piece is provided, in which a cushioning portion is formed on the base of a package and allowed to contact parts for contact of arm portions which are any parts but their edges, and the parts for contact of the arm portions that contact the cushioning portion are electrodeless regions, which prevents the risk of frequency fluctuations caused by any electrode being chipped off by contact with the cushioning portion.

A crystal resonator includes: lower glass plates on which first electrodes are formed so as to extend from side surfaces to a bottom surface of the lower glass plates; a crystal plate which is provided over the lower glass plates and on which second electrodes to be coupled to the first electrodes are formed on a surface in contact with the lower glass plates; and an upper glass plate which is provided over the crystal plate; wherein the side surfaces of the lower glass plates on which the first electrodes are formed are provided with a protrusion that extends in parallel with a top surface and the bottom surface of the lower glass plates and that extends from one end to the other end of each of the side surfaces, and wherein the first electrodes are formed on the side surfaces that include surfaces of the protrusion.

An oscillator includes: a resonator element; a circuit element configured to output a clock signal; and a container accommodating the resonator element and the circuit element and including a substrate having a first surface. The substrate includes a first electrode provided on the first surface and electrically coupled to the resonator element, a second electrode electrically coupled to the resonator element, and an output electrode configured to output the clock signal. The first electrode and the second electrode are disposed side by side in a first direction. The output electrode is disposed adjacent to the first electrode in a second direction orthogonal to the first direction. When an end portion of the first electrode on a side close to the second electrode is defined as a first end portion, the output electrode includes a first region disposed closer to the second electrode side than the first end portion in the first direction.

An oscillator includes: a resonator element; a circuit element; and a container including a substrate mounted with the circuit element, in which the circuit element includes a first coupling terminal coupled to the resonator element, a second coupling terminal coupled to the resonator element and aligned in a first direction with the first coupling terminal in the first direction, and an output terminal disposed adjacent to the first coupling terminal in a second direction orthogonal to the first direction, in the second direction orthogonal to the first direction, and in which the substrate includes a first surface mounted with the circuit element and a second surface, and the substrate includes a first coupling electrode provided on the first surface and coupled to the first coupling terminal, a second coupling electrode coupled to the second coupling terminal, an output electrode coupled to the output terminal, a first coupling wiring provided on the second surface and coupled to the first coupling electrode, a second coupling wiring coupled to the second coupling electrode, an output wiring coupled to the output electrode, and a shield wiring that is provided between the first coupling wiring and the output wiring and to which a direct-current potential is applied.

A crystal blank includes a vibrating arm which extends in a direction intersecting the polarization direction. In at least one of the upper surface and lower surface which are parallel to the direction of extension of the vibrating arm and run along polarization direction, the vibrating arm is provided with two recesses (grooves) in the width direction of the surface thereby having a pair of outer walls which are positioned on the two sides of the two recesses and a middle wall which is positioned between the two recesses. In the middle wall, the apex part is located at a position lower than the apex part of each of the pair of outer walls and is thinner than each of the pair of outer walls at the same heights.