The invention relates to microelectromechanical systems (MEMS), and specifically to a mirror system, for example to be used in LiDAR (Light Detection and Ranging). The MEMS mirror system of the invention uses four suspenders, each of which is connected to the reflector body at two separate connection points which can be independently displaced by piezoelectric actuators. By actuating adjacent and opposite pairs of piezoelectric actuators, the reflector body can be driven to oscillated about two orthogonal axes.

A light scanning device includes a mirror device that includes a movable mirror which swings about at least one axis, and a package that has at least two or more light transmission surfaces not constituting the same plane and accommodates the mirror device, in which out of the two or more light transmission surfaces of the package, one light transmission surface is a light receiving surface for receiving an incidence ray on the movable mirror from an outside, and the other light transmission surface is a light extraction surface for extracting light reflected by the movable mirror to the outside.

An image forming apparatus includes a light emitting device that emits light, a movable mirror that reflects the light emitted from the light emitting device, a first actuator that causes the movable mirror to swing about a first axis, a first reference signal output portion that outputs a first reference signal by estimating a point in time when a deflection angle of the movable mirror about the first axis becomes equal to a first reference angle, a light emission controller that causes the light emitting device to emit the light based on the first reference signal output from the first reference signal output portion, an imaging apparatus that images the light reflected by the movable mirror, and a correction portion that corrects a timing of the first reference signal output by the first reference signal output portion based on imaging information acquired by the imaging apparatus.

A microelectromechanical structure includes a body of semiconductor material having a fixed frame internally defining a cavity, a mobile mass elastically suspended in the cavity and movable with a first resonant movement about a first rotation axis and with a second resonant movement about a second rotation axis, orthogonal to the first axis. First and second pairs of supporting elements, extending in cantilever fashion in the cavity, are rigidly coupled to the frame, and are piezoelectrically deformable to cause rotation of the mobile mass about the first and second rotation axes. First and second pairs of elastic-coupling elements are elastically coupled between the mobile mass and the first and the second pairs of supporting elements. The first and second movements of rotation of the mobile mass are decoupled from one another and do not interfere with one another due to the elastic-coupling elements of the first and second pairs.

A driving controller provides a first driving signal having a first driving frequency to a first actuator that causes a mirror portion to swing around a first axis, provides a second driving signal having a second driving frequency to a second actuator that causes the mirror portion to swing around a second axis intersecting with the first axis, and derives a first driving condition of the first actuator under which the first driving frequency is less than a first resonance frequency around the first axis.

A driving controller provides a first driving signal having a first driving frequency to a first actuator, provides a second driving signal having a second driving frequency to a second actuator, derives a first average phase delay time by averaging a first phase delay time of an output signal of a first angle detection sensor with respect to the first driving signal in a plurality of cycles, derives a second average phase delay time by averaging a second phase delay time of an output signal of a second angle detection sensor with respect to the second driving signal in a plurality of cycles, generates a first reference signal based on the first driving signal and the first average phase delay time, and generates a second reference signal based on the second driving signal and the second average phase delay time.

The embodiments described herein include scanners that can provide improved scanning laser devices. Specifically, the embodiments described herein provide scanners with a modular construction that includes one or more separately formed piezoelectric actuators coupled to a microelectromechanical system (MEMS) scan plate, flexure structures, and scanner frame. Such modular scanners can provide improved scanning laser devices, including scanning laser projectors and laser depth scanners, LIDAR systems, 3D motion sensing devices, gesture recognition devices, etc.

The techniques disclosed herein provide apparatus, methods and systems that adaptively adjust the signal waveform (or waveshape) of the drive signal to a slow-scan mirror to compensate for non-linearities observed in the slow-scan feedback signal from a slow-scan mirror. Over large scan angles and high temperatures, the slow-scan mirror in a laser beam scanning device may exhibit a nonlinear response to the drive signal that results in poor image quality issues such as bright lines, bands in the display image, and image distortion. The presently disclosed technologies track the linearity performance of the overall system by detecting non-linearities in waveform of the slow-scan feedback signal real time, and consequently apply a pre-distortion to the drive waveform to compensate for these detected non-linearities. The parameters, logic and blocks of the control may be implemented in hardware, software or combinations thereof.

A microelectromechanical mirror device has, in a die of semiconductor material: a fixed structure defining a cavity; a tiltable structure carrying a reflecting region elastically suspended above the cavity; at least a first pair of driving arms coupled to the tiltable structure and carrying respective piezoelectric material regions which may be biased to cause a rotation thereof around at least one rotation axis; elastic suspension elements coupling the tiltable structure elastically to the fixed structure and which are stiff with respect to movements out of the horizontal plane and yielding with respect to torsion; and a piezoresistive sensor configured to provide a detection signal indicative of the rotation of the tiltable structure. At least one test structure is integrated in the die to provide a calibration signal indicative of a sensitivity variation of the piezoresistive sensor in order to calibrate the detection signal.

An optical reflector element includes: a pair of vibrator groups each of which includes tuning fork vibrators that are coupled together such that vibration centers of the tuning fork vibrators align on an imaginary rotational axis; a reflective body interposed between the pair of vibrator groups; a pair of supports that couple the pair of vibrator groups and the reflective body together; and a base to which the pair of vibrator groups are coupled in a manner that allows the pair of vibrator groups to vibrate.