Abstract: An image projection device includes: a light source; an optical scanning element; an optical member that projects the light in a circumferential direction; a sensor that detects the deflection angle and the rotation angle at a specific time point or consecutive time points in a specific period; and a processor, in which the processor determines a target scanning trajectory of a movable mirror, which is necessary for projecting a target image, and a target light emission timing in the target scanning trajectory, drives the optical scanning element based on the target scanning trajectory, calculates a trajectory of the movable mirror based on a detection value of the sensor, determines a light emission timing based on the target light emission timing and the trajectory of the movable mirror, and causes the light source to emit the light based on the determined light emission timing.

Abstract: An optical scanning device of the present disclosure includes: a micromirror device including a mirror that has a reflecting surface for reflecting light and is swingable around at least one axis, and an actuator that allows the mirror to swing; a control device configured to control an operation of the actuator; a light irradiation device configured to irradiate a back surface of the mirror on a side opposite to the reflecting surface with illumination light; a detection device to which reflected light of the illumination light that has been reflected by the mirror is incident and configured to output a position signal representing a position of the incidence light; and an abnormality detection device configured to detect an abnormal operation of the mirror based on a temporal fluctuation amount of the position signal.

Abstract: An optical scanning device of the present disclosure includes: a micromirror device including a mirror that has a reflecting surface for reflecting light and is swingable around at least one axis, an actuator that allows the mirror to swing, and a piezoelectric element that generates and outputs electromotive force by the swinging of the mirror; a control device configured to control an operation of the actuator; and an abnormality detection device configured to detect an abnormal operation of the mirror based on a temporal fluctuation amount in an output signal from the piezoelectric element.

Abstract: An optical scanning device includes: a micromirror device, a first actuator that allows the mirror portion to swing around a first axis, and a second actuator that allows the mirror portion to swing around a second axis orthogonal to the first axis; and a processor that causes the mirror portion to perform precession by providing a first driving signal and a second driving signal each having the same driving frequency to the first actuator and the second actuator, respectively. In the micromirror device, a relationship of f2 < f1 is satisfied in a case in which a resonance frequency around the first axis is denoted by f1 and a resonance frequency around the second axis is denoted by f2, and a relationship of fd ? f1 is satisfied in a case in which the driving frequency is denoted by fd.

Abstract: A driving controller applies a first driving signal Vx(t) including two components of different frequencies f1 and f2 represented by the following equation (A) to a first actuator and a second driving signal Vy(t) including components of the frequencies f1 and f2 represented by the following equation (B) to a second actuator. VX(t)=Ax1sin(2?f1t)+Ax2sin(2?f2t+?3). . . ??(A) Vy(t)=Ay1sin(2?f1t+?1)+Ay2sin(2?f2t+?3+?22). . .

Abstract: A resonance mode of one lower order than a basic resonance mode closest to a frequency of a cyclic voltage signal exists in at least any one of a plurality of resonance modes accompanied by a mirror tilt swing around a first axis or a plurality of resonance modes accompanied by the mirror tilt swing around a second axis.

Abstract: An optical scanning device causes a mirror portion to perform a spiral rotation operation with a first driving signal applied to a first actuator and a second driving signal applied to a second actuator as cyclic voltage signals. In a case where a resonance frequency and a resonance Q value of a resonance mode, among resonance modes accompanied by mirror tilt swing around a first axis, closest to a frequency of the cyclic voltage signal are respectively set as fr1 and Q1, a resonance frequency and a resonance Q value of a resonance mode, among resonance modes accompanied by mirror tilt swing around a second axis, closest to the frequency of the cyclic voltage signal are respectively set as fr2 and Q2, and the frequency of the cyclic voltage signal is fd, a relationship of Q1?Q2, Fr2<fr1, and fr2×(1?1/(1.2×Q2))?fd?fr1×(1+1/(6×Q1)) is satisfied.

Abstract: A micromirror device includes: a mirror portion; a first support portion that swingably supports the mirror portion around a first axis; a movable frame that is connected to the first support portion; a second support portion that swingably supports the mirror portion, the first support portion, and the movable frame around a second axis; a pair of first actuators that are connected to the second support portion and face each other across the second axis; a second actuator that surrounds the first actuator; a first connecting portion that connects the first actuator and the second actuator; a fixed frame that surrounds the second actuator; and a second connecting portion that connects the second actuator and the fixed frame. The second actuator applies rotational torque around the first axis to the mirror portion. The first actuator applies rotational torque around the second axis to the movable frame.

Abstract: Provided is an optical scanning device including: a mirror portion that reflects incident light; a first actuator that allows the mirror portion to swing around a first axis; a second actuator that allows the mirror portion to swing around a second axis which is orthogonal to the first axis; a pair of first angle detection sensors that output a signal corresponding to an angle of the mirror portion around the first axis, the pair of first angle detection sensors being disposed at positions facing each other across the first axis or the second axis; and at least one processor, in which the processor generates a first angle detection signal representing the angle of the mirror portion around the first axis by adding or subtracting a pair of first output signals output from the pair of first angle detection sensors.

Abstract: In a micromirror device, in a case where a resonance frequency around a first axis is denoted by f1 and a resonance frequency around a second axis is denoted by f2, a relationship of f1<f2 is satisfied, and in a case where a mirror portion is driven around the first axis and the second axis simultaneously, the resonance frequency around the first axis changes by ?f from f1. A first driving signal and a second driving signal each having a driving frequency fd satisfying a relationship of f1??f<fd are provided to a first actuator and a second actuator, respectively, to cause the mirror portion to perform precession.

Abstract: An optical scanning device includes a mirror device that has a mirror portion, which is swingable around a first axis and a second axis orthogonal to each other, having a reflecting surface reflecting incident light, a first actuator causing the mirror portion to swing around the first axis by applying a rotational torque around the first axis to the mirror portion, and a second actuator causing the mirror portion to swing around the second axis by applying a rotational torque around the second axis to the mirror portion, and a processor that provides a first driving signal to the first actuator and provides a second driving signal to the second actuator. The processor, with the first driving signal and the second driving signal each as cyclic voltage signals whose amplitudes and phases change with time, causes the mirror portion to perform a spiral rotation operation including a period in which a swing amplitude around the first axis and a swing amplitude around the second axis change linearly.

Abstract: The piezoelectric microphone chip includes a single thin plate, a diaphragm support structure that is provided on one surface of the thin plate and includes an outer edge support portion that supports an outer edge of the thin plate and a separation support portion that separates the thin plate into a plurality of diaphragms in association with the outer edge support portion, a single or a plurality of piezoelectric conversion portions formed by laminating a first electrode, a piezoelectric film, and a second electrode sequentially from a diaphragm side on each of the diaphragms, and a signal detection circuit that detects outputs from the piezoelectric conversion portions provided on the plurality of diaphragms, and a relationship among a thickness t1 of the outer edge support portion, a thickness t2 of the separation support portion, and a thickness td of the thin plate 10 is set to 13.3×td<t2<t1?20 ?m.

Abstract: A micromirror device includes: a mirror part; a first actuator in which a pair of semi-annular actuator parts surrounds the mirror part; a connecting part that connects the mirror part and the first actuator such that the mirror part is rotatable around a first axis; a fixing part that is disposed at an outer periphery of the first actuator; and a second actuator in which a pair of meandering type actuator parts are disposed with the first actuator interposed therebetween. Each of the pair of meandering type actuator parts is disposed such that a longitudinal direction of the rectangular plate-like part is a direction along the first axis, one end of each meandering type actuator part is connected to an outer periphery of each of the pair of semi-annular actuator parts, and another end of each meandering type actuator part is connected to the fixing part.

Abstract: In a micromirror device, the upper electrode of the piezoelectric element consists of a plurality of individual electrode parts, each of which is separated by a first stress inversion region and a second stress inversion region. In the first stress inversion region, positive and negative, of a principal stress component having a maximum absolute value among a principal stress, are inverted in a maximum displacement state, in a case of driving in a first resonance mode in which the mirror part is tilted and oscillated around the first axis. In the second stress inversion region, positive and negative, of a principal stress component having a maximum absolute value among a principal stress, are inverted, in a case of driving in a second resonance mode in which the mirror part is tilted and oscillated around the second axis.

Abstract: A micromirror device includes first and second actuators, which are piezoelectric actuators each having a piezoelectric element in which a lower electrode, a piezoelectric film, and an upper electrode are laminated on an oscillation plate. In each of the piezoelectric elements, each upper electrode is formed of a plurality of individual electrode parts, each of which is separated by a first stress inversion region and a second stress inversion region, and includes a plurality of piezoelectric parts respectively defined by the plurality of individual electrode parts.

Abstract: Provided are a piezoelectric element having high stability, which operates with high efficiency, and a method for manufacturing the piezoelectric element. The piezoelectric element (10) has a laminate structure in which a first electrode (14), a first piezoelectric film (16), a second electrode (18), an adhesion layer (20), an interlayer (22), a third electrode (24), a second piezoelectric film (26), and a fourth electrode (28) are laminated in this order on a silicon substrate (12). The interlayer (22) is formed of a material different from that of the second electrode (18) and has a thickness of 0.4 ?m to 10 ?m. A device having a diaphragm structure or a cantilever structure is formed by removing a part of the silicon substrate (12). The respective layers (14 to 28) laminated on the silicon substrate (12) can be formed using a thin film formation method represented by a vapor phase epitaxial method.

Abstract: A piezoelectric element is obtained using a method including: preparing a first structure; preparing a second structure; disposing a first facing electrode layer of the first structure to face a first surface of a vibration plate substrate and bonding the first structure to the first surface of the vibration plate substrate; processing the vibration plate substrate into a vibration plate by polishing or etching a second surface of the vibration plate substrate to which the first structure is bonded; preparing a laminate structure by disposing a second facing electrode layer of the second structure to face an exposed surface of the vibration plate and bonding the second structure to the vibration plate; and removing at least a part of a first silicon substrate of the first structure and a second silicon substrate of the second structure from the laminate structure.

Abstract: A micromirror device includes: a mirror portion that has a reflective surface reflecting incident light; a first actuator that has an annular shape and is disposed around the mirror portion; a second actuator that has an annular shape and is disposed around the first actuator; a first connection portion that connects the mirror portion and the first actuator on a first axis, which is in a plane including the reflective surface of the mirror portion in a stationary state, and that rotatably supports the mirror portion around the first axis; a second connection portion that connects the first actuator and the second actuator on a second axis, which is in a plane including the reflective surface of the mirror portion in a stationary state and is orthogonal to the first axis, and that rotatably supports the first actuator around the second axis; a third connection portion that is connected to an outer circumference of the second actuator on the second axis; and a fixed portion that is connected to the third conne

Abstract: A piezoelectric device and a manufacturing method thereof in which a piezoelectric film formed of a thin film of a lead zirconate titanate-based perovskite oxide is formed on a substrate, and at least a first region out of the first region and a second region of the piezoelectric film is irradiated with electromagnetic waves having a wavelength of 230 nm or less in a reducing atmosphere to provide a difference in piezoelectric characteristics between the first region and the second region so that the first region has a smaller absolute value of a piezoelectric constant d31 and a smaller dielectric loss tan ? than the second region.

Abstract: The piezoelectric microphone chip includes a single thin plate, a diaphragm support structure that is provided on one surface of the thin plate and includes an outer edge support portion that supports an outer edge of the thin plate and a separation support portion that separates the thin plate into a plurality of diaphragms in association with the outer edge support portion, a single or a plurality of piezoelectric conversion portions formed by laminating a first electrode, a piezoelectric film, and a second electrode sequentially from a diaphragm side on each of the diaphragms, and a signal detection circuit that detects outputs from the piezoelectric conversion portions provided on the plurality of diaphragms, and a relationship among a thickness t1 of the outer edge support portion, a thickness t2 of the separation support portion, and a thickness td of the thin plate 10 is set to 13.3×td<t2<t1?20 ?m.