A piezoelectric actuator comprises a substrate, an insulator layer on the substrate, and a piezo actuator stack on the insulator layer. The piezo actuator stack comprises an insulator-adjacent electrode on the insulator layer. A piezo layer having a tapered sidewall resides on a portion of the insulator-adjacent electrode. An insulator-distal electrode on the piezo layer having a taper-adjacent edge offset from an intersection of the tapered sidewall of the piezo layer and the insulator-adjacent electrode.

A micro scanning mirror, including a fixed substrate, a lens, and multiple cantilevers, are provided. Each cantilever includes a piezoelectric material structure, multiple first drive electrodes, and multiple second drive electrodes. The piezoelectric material structure includes a connecting part, a folding part, and a fixed part. The connecting part connects the lens along a direction parallel to a central axis of the lens. The folding part has a bending region and multiple drive electrode regions. The fixed part is connected to the fixed substrate, and the folding part is connected to the connecting part and the fixed part. The first drive electrodes and the second drive electrodes are respectively located in the corresponding drive electrode regions in the folding part. The micro scanning mirror of the disclosure can drive a large-sized micro mirror to rotate at an appropriate rotation angle.

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 metal substrate supported by a wiring substrate includes a first extending portion and a first connection portion connected to the first extending portion. The first connection portion includes a first region facing a portion of a wiring substrate in a Z-axis direction, a second region being continuous from the first region, and a third region being continuous from the second region. When viewed in the Z-axis direction, in a direction perpendicular to a connection direction in which the third region is connected to the second region, a width of the second region is larger than a width of the third region. A first bonding member bonding the wiring substrate and the metal substrate includes a first portion disposed between the portion and the first region, and a second portion being continuous from the first portion. The second portion reaches the second region but does not reach the third region.

A piezoelectric drive element disposed on a placement surface of a metal substrate includes a piezoelectric drive body having a first main surface opposite the placement surface, a second main surface on a placement surface side, and a side surface, and a first electrode disposed on the first main surface. The piezoelectric drive element is disposed on the placement surface such that a part of the placement surface is located outside the side surface. A second bonding member having conductivity includes a first portion disposed between the placement surface and the piezoelectric drive element, and a second portion being continuous from the first portion and disposed in a corner formed by the part of the placement surface and the side surface. The second portion does not reach the first electrode.

A metal substrate supported by a wiring substrate includes a movable portion, a first extending portion, a first coupling portion that couples the first extending portion and the movable portion, and a first connection portion connected to the first extending portion. The first connection portion includes a first fixing region fixed to the wiring substrate, and a first connection region connected to the first extending portion and to the first fixing region. The first connection region includes a first bent portion. The first bent portion has a first outer edge on a movable portion side, and a second outer edge opposite the movable portion, and each of the first outer edge and the second outer edge is bent toward the movable portion side when viewed in a Z-axis direction.

Examples are disclosed herein related to controlling a scanning mirror system. One example provides a display device, comprising a light source, a scanning mirror system configured to scan light from the light source in a first direction at a first, higher scan rate, and in a second direction at a second, lower scan rate, and a drive circuit configured to control the scanning mirror system to display video image data by providing a control signal to the scanning mirror system to control scanning in the second direction, and for each video image data frame of at least a subset of video image data frames, combining the control signal with an adjustment signal to adjust the scanning in the second direction, the adjustment signal comprising a low pass filtered signal with a cutoff frequency based on a lowest resonant frequency of the scanning mirror system in the second direction.

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 scanning device includes a control unit, a light deflector, light detection units, and a light source. A mirror unit of the light deflector has a flat reflection part for generating scanning light and a groove-shaped reflection part for generating twice reflected light, and performs reciprocating rotation about a rotation axis. The light detection units are disposed at positions on the scanning trajectory of the scanning light where the twice reflected light is received, and are each divided into light detectors in the scanning direction of the scanning light by a division line. The control unit detects the deflection angle θ of the mirror unit based on both the output of the light detector and the output of the light detector.

A distally-actuated scanning mirror includes: a mirror block with reflective surface on one side; torsional hinges with proximal ends rigidly attached to the mirror block, and with distal ends attached to flexural structures configured to transform translational motion of the piezoelectric elements into rotational motion of the distal ends of the hinges; and piezoelectric elements providing such translational motion. The distally-actuated scanning mirror also includes flexural structures made of separate flexures attached to the opposite surfaces of the distal ends of the hinges, which flexural structures have defined thinned-down flexural points. Portions of the distally-actuated scanning mirror may be 3D printed and/or fabricated by silicon MEMS technology. The mirror is fabricated from a Silicon-on-Insulator wafer, having a relatively thick (e.g., 380 um) handle layer, and a relatively thin e.g., 50 um), where photolithography with backside-alignment allows separate patterning of these two layers.