A light deflector 2 includes: a mirror section 9 that reflects light; a movable frame 8 provided in such a manner as to surround the mirror section 9; a pair of torsion bars 13a and 13b having one end of each torsion bar connected to the mirror section 9 and the other end thereof connected to the movable frame 8 on a Y-axis; and semi-annular piezoelectric actuators 10a and 10b that are provided on the movable frame 8 and rotate the torsion bars 13a and 13b around the Y-axis in a reciprocating manner. The torsion bars 13a and 13b each have a constricted shape in which the transverse width at both end parts is the largest and the transverse width gradually decreases toward the central part thereof in a length direction.

A hinge for a micromechanical and/or nanomechanical structure includes: a support, and a movable part in an out-of-plane direction. The hinge allows for the out-of-plane displacement of the movable part. The hinge further includes two torsion beams extending along the axis of rotation of the hinge, two bending elements mechanically connecting the movable part and the support and having at least one pair of a first and of a second beam parallel with each other and extending in a plane perpendicular to the axis of rotation, the first beam being connected to the support and the second beam being connected to the movable part, the first and second beams being connected to one another by a first connecting element at a longitudinal end, the two beams extending in the same direction from the first connecting element.

An optical scanning device includes a reflector as a MEMS mirror having a reflection surface of a metal film, a support body, a drive beam, and a drive unit. The support body is disposed to be spaced from the reflector so as to surround the reflector. The drive beam connects the reflector and the support body. A first protection film is formed all over opposite side surfaces including side wall surfaces of a second semiconductor layer, as well as an upper surface and a lower surface, in the drive beam. As the first protection film, a silicon oxide film, a silicon nitride film, an alumina film, or a titania film is formed by an atomic layer deposition method.

An optical device includes an elastic support portion which includes a torsion bar extending in a second direction perpendicular to a first direction and a nonlinearity relaxation spring connected between the torsion bar and a movable portion. The nonlinearity relaxation spring is configured so that a deformation amount of the nonlinearity relaxation spring around the second direction is smaller than a deformation amount of the torsion bar around the second direction and a deformation amount of the nonlinearity relaxation spring in a third direction perpendicular to the first direction and the second direction is larger than a deformation amount of the torsion bar in the third direction while the movable portion moves in the first direction. A first comb finger of a first comb electrode and a second comb finger of a second comb electrode which are adjacent to each other face each other in the second direction.

MEMS devices include fluid confinement structures on either a fixed part of a substrate and/or on a suspended element. The fluid confinement structures may be configured to confine a viscoelastic fluid in a limited part of a gap between one or more vertical sidewalls of both the fixed part of the substrate and either the suspended element or the drive beam or both the suspended element and drive beam such that one part of the gap is bridged by the fluid and another part of the gap is not, The structures may be configured to prevent flow of the fluid to other parts of the gap.

Micro-electro-mechanical systems and a preparation method thereof are provided. The micro-electro-mechanical systems include first fixed comb fingers, second fixed comb fingers, a support beam, a movable platform, and movable comb fingers. The first fixed comb fingers and the second fixed comb fingers are fastened to a substrate, and the first fixed comb fingers are electrically isolated from the second fixed comb fingers. Two ends of the support beam are fastened to the substrate, and the movable platform is coupled to the support beam. The movable comb fingers are coupled to the movable platform, and form a three-layer comb finger structure with the first fixed comb fingers and the second fixed comb fingers. This structure improves drive efficiency of the micro-electro-mechanical systems.

The micromirror device includes: a movable portion having a mirror portion on which a reflecting surface for reflecting incident light is formed; a first support portion that is connected to the movable portion on a first axis located in a plane including the reflecting surface of the mirror portion in a stationary state, and that swingably supports the movable portion around the first axis; and a pair of first actuators that are connected to the first support portion and face each other across the first axis, each of which being a piezoelectric drive type first actuator that allows the movable portion to swing around the first axis, in which in a case where the movable portion swings around the first axis, at least a part of the first actuator swings around the first axis in a phase opposite to a phase of the movable portion, and assuming that a ratio of a rotation angle of the first actuator to a rotation angle of the movable portion is R, 0<R<1.00 is satisfied.

A microelectromechanical system (MEMS) device including an oscillator structure configured to oscillate about a rotation axis; a frame that is rotationally fixed, the frame including a frame recess within which the oscillator structure is suspended; and a suspension assembly mechanically coupled to and between the oscillator structure and the frame, the suspension assembly configured to suspend the oscillator structure within the frame recess. The suspension assembly includes a central support beam that extends lengthwise along the rotation axis, the central support beam being mechanically coupled to and between the oscillator structure and the frame; a first outer support beam mechanically coupled to the oscillator structure and laterally displaced from the central support beam in a first direction orthogonal to the rotation axis; and at least one first interior support beam directly coupled to and between the central support beam and the first outer support beam.

A mirror unit 2 includes a mirror device 20 including a base 21 and a movable mirror 22, an optical function member 13, and a fixed mirror 16 that is disposed on a side opposite to the mirror device 20 with respect to the optical function member 13. The optical function member 13 is provided with a light transmitting portion 14 that constitutes a part of an optical path between the beam splitter unit 3 and the fixed mirror 16. The light transmitting portion 14 is a portion that corrects an optical path difference that occurs between an optical path between the beam splitter unit 3 and the movable mirror 22 and the optical path between the beam splitter unit 3 and the fixed mirror 16. The second surface 21b of the base 21 and the third surface 13a of the optical function member 13 are joined to each other.

A light deflector includes a stationary part; a movable unit having a reflecting surface; a connecting part between the movable unit and the stationary part; a drive unit disposed on a first surface of the connecting part, the drive unit configured to deform the connecting part to oscillate the movable unit; and a rib disposed on a second surface of the connecting part, the second surface being an opposite surface of the first surface. The rib includes a portion whose longitudinal direction is orthogonal to a direction at which the connecting part is bent.