Patent ID: 8766514

Claim:
A piezoelectric resonator element comprising: a piezoelectric substrate formed of an AT-cut quartz crystal substrate in which in an orthogonal coordinate system made up of the crystal axes of a quartz crystal, which are an X axis serving as an electrical axis, a Y axis serving as a mechanical axis, and a Z axis serving as an optical axis, an axis which is the Z axis tilted in a −Y direction of the Y axis about the X axis is a Z′ axis, and an axis which is the Y axis tilted in a +Z direction of the Z axis about the X axis is a Y′ axis, in which the AT-cut quartz crystal substrate is configured by a plane parallel to the X axis and the Z′ axis, and the thickness direction thereof is a direction parallel to the Y′ axis; and excitation electrodes disposed so as to face vibrating regions on both front and rear principal surfaces of the piezoelectric substrate, wherein the piezoelectric substrate includes a rectangular excitation portion in which sides parallel to the X axis are long sides thereof, and sides parallel to the Z′ axis are short sides thereof; and a peripheral portion having a smaller thickness than the excitation portion and formed around the long sides and the short sides of the excitation portion, wherein the excitation portion includes multiple steps placed between a center of the peripheral portion and the excitation portion extending in a direction parallel to the X axis, and wherein the excitation portion includes a single step placed between the center of the peripheral portion and the excitation portion extending in a direction parallel to the Z′ axis.