Murata Manufacturing Co., Ltd.

Matti Liukku

Ville-Pekka Rytkönen

Anssi Blomqvist

Altti Torkkeli

Hannu Vesterinen

Antti Iihola

Jaakko Ruohio

Ville Pekka Rytkönen

Jouni Erkkilä

Tero Sillanpää

Severi Niskanen

An accelerometer comprising a first proof mass and a second proof mass which are coupled to each other with a coupling structure which extends from the first proof mass to the second proof mass. The coupling structure synchronizes the movement of the first and second proof masses so that the first and second proof masses may be linearly displaced from their rest position in the x-direction, rotationally displaced in opposite in-plane directions and rotationally displaced in opposite out-of-plane directions.

Three-axis accelerometer with two masses

A microelectromechanical accelerometer is provided that includes one or more proof masses. The accelerometer also includes four sets of stator combs that form a set of four measurement capacitors together with rotor combs. Some rotor combs have a positive offset in a direction in the device plane in relation to stator, while others have a negative offset. Some rotor combs have a negative offset in a direction perpendicular to the device plane in relation to stator combs. Moreover, some stator combs have a negative offset in the direction perpendicular to the device plane in relation to rotor combs.

In-plane and out-of-plane accelerometer

A microelectromechanical accelerometer for measuring acceleration, comprising a first proof mass and ae second proof mass. The first proof mass is adjacent to the second proof mass. A suspension structure allows the first proof mass to undergo rotation out of the device plane about a first rotation axis and the suspension structure allows the second proof mass to undergo rotation out of the device plane about a second rotation axis. The first and second rotation axes are parallel to each other and define an x-direction which is parallel to the first and the second rotation axes and a y-direction which is perpendicular to the x-direction. The y-coordinate of the first rotation axis is greater than the y-coordinate of the second rotation axis by a nonzero distance D.

Seesaw accelerometer

An accelerometer for measuring acceleration in the direction of a z-axis which is perpendicular to an xy-plane, where a first proof mass is suspended from a first side anchor point with a first suspension structure which allows the first proof mass to undergo rotation about a first rotation axis. A second proof mass is suspended from a second side anchor point with a second suspension structure. The second suspension structure allows the second proof mass to undergo rotation about a second rotation axis. The torsion elements in the first and second suspension structure lie further away from the center of the accelerometer than the corresponding side anchor points from which the masses are suspended.

Accelerometer with two seesaws

A capacitive microelectromechanical acceleration sensor where one or more rotor measurement plates and one or more stator measurement plates are configured so that the movement of a proof mass in the direction of a sense axis can be measured in a capacitive measurement conducted between them. One or more first rotor damping plates and one or more first stator damping plates form a first set of parallel plates which are orthogonal to a first damping axis, and the first damping axis is substantially orthogonal to the sense axis.

Vibration damping in MEMS acceleration sensors

The present invention relates to MEMS (microelectromechanical systems) accelerometers, in particular to an accelerometer designed to reduce error in the accelerometer output. The MEMS accelerometer includes a proof mass, which is capable of movement along at least two perpendicular axes and at least one measurement structure. The proof mass is mechanically coupled to the measurement structure along the sense axis of the measurement structure, such that movement of the proof mass along the sense axis causes the moveable portion of the measurement structure to move, and is decoupled from the measurement structures along an axis or axes perpendicular to the sense axis of the measurement structure, such that movement of the proof mass perpendicular to the sense axis of the measurement structure does not cause the moveable portion of the measurement structure to move.

MEMS accelerometer with mechanically decoupled proof mass

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.

Two-axis MEMS mirror with separated drives

The present invention provides a high-accuracy low-noise MEMS accelerometer by using at least two symmetric out-of-plane proof masses for both out-of-plane and in-plane axes. Movement of the proof masses in one or more in-plane sense axes is measured by comb capacitors with mirrored comb electrodes that minimise cross-axis error from in-plane movement of the proof mass out of the sense axis of the capacitor. The two out-of-plane proof masses rotate in opposite directions, thus maintaining their combined centre of mass at the centre of the accelerometer even as they rotate out of plane.

Low-noise multi-axis MEMS accelerometer

A microelectromechanical system with at least one partly mobile mass element which is suspended from a fixed support by one or more suspension units. Each suspension unit comprises first springs which extend from the fixed support to the partly mobile mass element, and second springs which also extend from the fixed support to the partly mobile mass element. Each second spring is substantially parallel and adjacent to one first spring. The first springs are electrically isolated from the second springs, and the microelectromechanical system comprises a voltage source configured to apply a frequency tuning voltage between the one or more first springs and the one or more second springs.

MEMS frequency-tuning springs

A capacitive micromechanical accelerometer comprising a first proof mass, a second proof mass, a third proof mass and a fourth proof mass. Each proof mass is configured as a seesaw which undergoes rotation out of the xy-plane in response to z-axis acceleration. The four proof masses are suspended from the same central anchor point with torsionally flexible suspension arrangements. Errors introduced into the output signal by wafer bending can be automatically compensated in a differential capacitive measurement.

Robust z-axis acceleration sensor

The disclosure relates to a microelectromechanical device where the device structure includes a rotating mass structure and a linear mass structure. The rotating mass structure is formed of two rotating mass parts elastically coupled to the support through one or more springs that enable rotary motion of each of the rotating mass parts about respective rotary axes that extend parallel to each other along a first in-plane direction (IP). The linear mass structure includes at least one elongate rigid body that extends in a second in-plane direction (IP). One end of the linear mass structure is coupled to the first rotating mass part and the other end of the linear mass structure is coupled to the second rotating mass part such that rotary motions of the first and second masses result into linear motion of the linear mass structure in the out-of-plane direction (OP).

Microelectromechanical device for out-of-plane motion detection

A scanning microelectromechanical reflector system comprising a mobile reflector mass and a mobile frame mass which surrounds the mobile reflector mass when the reflector plane coincides with the mobile frame plane. The mobile frame mass is suspended from a fixed frame which at least partly surrounds the mobile frame mass when the mobile frame plane coincides with the fixed frame plane. The reflector system further comprises a pair of first torsion beams aligned on a first axis in the mobile frame plane, and one or more first actuation units which can be configured to rotate the reflector mass and the mobile frame mass about the first axis.

Mems reflector system with trajectory control

An optical device that provides a broadened circular scanning pattern. The device includes a reflector system dimensioned to form a coupled oscillator with two modes of oscillation for circular tilt motion, a first mode oscillation in a first resonance frequency and a second mode of oscillation in a second resonance frequency that is different from the first resonance frequency. A signal processing element is configured to control the actuation signals to maintain a first amplitude in the first mode of oscillation, and a second amplitude in the second mode of oscillation.

Scanning optical device with broadened image area

A scanning microelectromechanical reflector system comprising a reflector with a reflector body, a first cavity vertically aligned with the reflector body above the device plane and a second cavity vertically aligned with the reflector body below the device plane. The reflector also comprises a central attachment point located within a central opening in the reflector body. One or more flexures extend from the sidewalls of the central opening to the central attachment point. The flexures allow the central attachment point to remain stationary in the device plane when actuator units tilt the reflector body out of the device plane. The reflector system comprises a central support structure which extends through the cavity to the central attachment point of the reflector.

MEMS reflector with center support

A compact and robust microelectromechanical reflector system that comprises a support, a reflector, a peripheral edge of the reflector including edge points, and suspenders including piezoelectric actuators and suspending the reflector from the support. Two pairs of suspenders are fixed from two fixing points to the support such that in each pair of suspenders, first ends of a pair of suspenders are fixed to a fixing point common to the pair. A first axis of rotation is aligned to a line running though the two fixing points, and divides the reflector to a first reflector part and a second reflector part. In each pair of suspenders, a second end of one suspender is coupled to the first reflector part and a second end of the other suspender is coupled to the second reflector part.

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Helsinki, Finland

Matti Liukku