A vibration device includes: a piezoelectric unit including a piezoelectric element; a housing that holds the piezoelectric unit; a wiring member electrically connected to the piezoelectric unit; and a joining member that joins the housing to an external device. The housing includes a bottom surface portion to which the piezoelectric unit is fixed, and a side surface portion standing at an edge portion of the bottom surface portion. The side surface portion has a first surface formed on a top portion of the side surface portion, and a second surface that is one step lowered from the first surface by a cutout portion formed in the top portion. The joining member extends along the first surface to bridge over the cutout portion. The wiring member is joined to the joining member at a position of the first surface, and passes through the cutout portion in a state where the wiring member is not joined to the second surface.

A vibration device includes: a piezoelectric unit including a piezoelectric element; and a housing made of metal that holds the piezoelectric unit. The housing includes a bottom surface portion to which the piezoelectric unit is fixed, and side surface portions that stand at an edge portion of the bottom surface portion to surround the piezoelectric unit. The side surface portions are continuous with the bottom surface portion, and are inclined to open outward from the edge portion with respect to the bottom surface portion.

A vibration device includes: a piezoelectric unit including a piezoelectric element; and a housing made of metal that holds the piezoelectric unit. The housing includes a bottom surface portion to which the piezoelectric unit is fixed, and side surface portions that stand at an edge portion of the bottom surface portion to surround the piezoelectric unit. The side surface portions are continuous with the bottom surface portion, and are inclined to open outward from the edge portion with respect to the bottom surface portion.

A quartz crystal unit comprising a quartz crystal resonator having a base portion, and first and second tuning fork arms connected to the base portion, the base portion having a length less than 0.5 mm and greater than a spaced-apart distance between the first and second tuning fork arms, each of the first and second tuning fork arms having a width less than 0.1 mm and a length less than 1.56 mm, and a plurality of different widths including a first width and a second width greater than the first width, at least one groove being formed in at least one of opposite main surfaces of each of the first and second tuning fork arms so that a length of the at least one groove is within a range of 0.3 mm to 0.79 mm, the quartz crystal resonator being housed in a case, and a lid being connected to the case.

A piezoelectric device includes a piezoelectric single crystal body with a homogeneous polarization state and of which at least a portion flexurally vibrates, an upper electrode on an upper surface of the piezoelectric single crystal body, a lower electrode on a lower surface of the piezoelectric single crystal body, and a supporting substrate below the piezoelectric single crystal body. A recess extends from a lower surface of the supporting substrate toward the lower surface of the piezoelectric single crystal body.

[Object] To provide a technology such as a piezoelectric coil having higher energy conversion efficiency.

[Solving Means] A piezoelectric coil according to the present technology includes a coil-like core material and a plurality of band-like piezoelectric materials. The plurality of piezoelectric materials is helically wound around the core material so as to be alternately arranged along the core material.

[Object] To provide a technology such as a piezoelectric coil having higher energy conversion efficiency.

[Solving Means] A piezoelectric coil according to the present technology includes a coil-like core material and a plurality of band-like piezoelectric materials. The plurality of piezoelectric materials is helically wound around the core material so as to be alternately arranged along the core material.

An apparatus includes a vibration member and a first cover disposed at a rear surface of the vibration member. The apparatus also includes a first vibration apparatus disposed at a rear surface of the first cover and configured to vibrate the vibration member. The apparatus includes a first enclosure member disposed at the rear surface of the first cover and at the rear surface of the vibration member. The apparatus also includes a first rear vibration member disposed at the first enclosure member.

A circuit module includes a mounting substrate including a conductor wiring, an elastic wave element provided in or on a main surface of the mounting substrate, an electric element provided in or on the main surface, the electric element being different from the elastic wave element, and an insulating resin portion provided in or on the main surface to cover the elastic wave element and the electric element. The elastic wave element and the electric element are connected to each other by the conductor wiring. A height of the elastic wave element is about 0.28 mm or less, which is less than that of the electric element. The thickness of the resin portion in a region in which the resin portion covers the elastic wave element is greater than the thickness of the resin portion in a region in which the resin portion covers the electric element.

A circuit module includes a mounting substrate including a conductor wiring, an elastic wave element provided in or on a main surface of the mounting substrate, an electric element provided in or on the main surface, the electric element being different from the elastic wave element, and an insulating resin portion provided in or on the main surface to cover the elastic wave element and the electric element. The elastic wave element and the electric element are connected to each other by the conductor wiring. A height of the elastic wave element is about 0.28 mm or less, which is less than that of the electric element. The thickness of the resin portion in a region in which the resin portion covers the elastic wave element is greater than the thickness of the resin portion in a region in which the resin portion covers the electric element.