A resonator that includes a vibrating portion that has a piezoelectric film, and a lower and upper electrodes that face each other with the piezoelectric film interposed therebetween. Moreover, a holding portion is provided at least around a maximum displacement region of the vibrating portion and has an insulating film. A holding arm connects the vibrating portion and the holding portion, and include a conductive portion that is in contact with the insulating film of the holding portion in at least a region that faces the maximum displacement region of the vibrating portion. In addition, the conductive portion is electrically connected to the lower electrode or the upper electrode or is grounded.

A physical quantity sensor includes a substrate, a beam part that includes a detection beam, a detection weight that is supported on the substrate through the beam part, and a detection piezoelectric film that is disposed on the detection beam and is configured to generate an electric output according to displacement of the detection beam caused by movement of the detection weight in a direction due to an application of a physical quantity. The detection beam includes a first detection beam and a second detection beam that are disposed to hold the detection weight at different positions from each other in the direction. The first detection beam and the second detection beam have different spring constants, and the detection piezoelectric film is disposed on the first detection beam.

A control device for controlling a switching converter includes a switch controller that generates a control signal with a switching period for controlling switching of a switch of the switching converter and setting a first interval in which a current flows in the switch, a second interval in which energy is transferred onto a storage element of the switching converter, and a third, wait, interval, at the end of the second interval. The duration of the first interval is determined based on a control voltage indicating the output voltage. A pre-distortion stage receives the control voltage and generates a pre-distorted control voltage as a function of the control voltage and a relationship between one of the first and third time intervals and the switching period, wherein the switch controller is configured to control a duration of the first interval based on the pre-distorted control voltage.

An actuator device includes a support portion; a first movable portion; a second movable portion; a first connection portion that connects the first and second movable portions such that the first movable portion is swingable around a first axis; a second connection portion that connects the second movable portion and the support portion such that the first movable portion is swingable around the first axis. Two natural angular frequencies ?.sub.1 and ?.sub.2 (where ?.sub.1<?.sub.2) for vibration of the first and second movable portions around the first axis satisfy one of the following equation (1) and equation (2) and do not satisfy the other,

[00001]$\begin{array}{cc}\left[\mathrm{Equation}1\right]& ?\\ 0<1-{\left(\frac{{?}_1}{{?}_{\mathrm{ii}}}\right)}^2?0.2& \left(1\right)\end{array}$$\begin{array}{cc}\left[\mathrm{Equation}2\right]& ?\\ 0<{\left(\frac{{?}_2}{{?}_{\mathrm{ii}}}\right)}^2-1?0.2& \left(2\right)\end{array}$

In the above equations, ?.sub.ii=(k.sub.i/j.sub.i).sup.1/2, k.sub.i is a torsional spring constant of the first connection portion around the first axis, and j.sub.i is an inertia moment of the first movable portion around the first axis.

A resonant structure comprising at least two coaxial rings, wherein adjacent coaxial rings have adjacent peripheries and are attached together by a plurality of connection structures regularly arranged along said adjacent peripheries; and wherein a first ring has a first ring portion with a first radial thickness and a second ring, portion, in a vicinity of a first connection structure, with a second radial thickness smaller than said first radial thickness.

Provided is a micro drive unit, which is capable of performing multi-axis drive, the micro drive unit including: a movable object; and at least one pair of beams configured to pivotally support the movable object and formed only in one direction, the movable object being configured to rotate or translate in an x-axis direction, a y-axis direction, and a z-axis direction when the at least one pair of beams is twisted or bent at one or a plurality of resonant frequencies of the at least one pair of beams, thereby being capable of simultaneously avoiding upsizing and complication of the structure. And by incorporating the micro drive unit, a micro device capable of achieving multi-axis drive can be manufactured.

A MEMS device includes a fixed structure and a mobile structure with a reflecting element coupled to the fixed structure through at least a first deformable structure and a second deformable structure. Each of the first and second deformable structures includes a respective number of main piezoelectric elements, with the main piezoelectric elements of the first and second deformable structures configured to be electrically controlled for causing oscillations of the mobile structure about a first axis and a second axis, respectively. The first deformable structure further includes a respective number of secondary piezoelectric elements configured to be controlled so as to vary a first resonance frequency of the mobile structure about the first axis.

Disclosed herein is a MEMS device including a fixed structure, a mobile structure, and deformable structures extending therebetween. The deformable structures have first ends anchored along X and Y axes of the fixed structure, and have second ends anchored offset from the X and Y axes of the fixed structure. The deformable structures are shaped so as to curve from their anchoring points along the mobile structure back toward the mobile structure, to extend along the perimeter of the mobile structure, and to then curve away from the mobile structure and toward their anchoring points along the fixed structure. Each deformable structure has two piezoelectric elements that extend along the length of that deformable structure, with one piezoelectric element having a greater length than the other piezoelectric element.

Isochronous pivot for a resonator including two flexible strips joining attachment points of a first and a second element, defining two strip directions, and a pivot axis, at the intersection of their projections or at their intersection, each strip having a free length between its attachment points, and an axial distance between the pivot axis and the attachment point thereof farthest from the axis, the attachment point ratio X=D/L being greater than one for each strip, the strip directions defining with the axis a first apex angle whose value in degrees is comprised between f1(X)=108+67/(10X6), and f2(X)=113+67/(10X6).

An isochronous pivot for a resonator including two flexible strips joining attachment points of a first and a second element, defining two strip directions, and a pivot axis, at the intersection of their projections or at their intersection, each strip having a free length between its attachment points, and an axial distance between the pivot axis and the attachment point thereof farthest from the axis, the attachment point ratio X=D/L being greater than one for each strip, the strip directions defining with the axis a first apex angle whose value in degrees includes between f1(X)=108+67/(10X6), and f2(X)=113+67/(10X6).