This disclosure is related to devices, systems, and techniques for determining an acceleration. For example, an accelerometer system includes a resonator and a light-emitting device configured to generate, based on an error signal, an optical signal. Additionally, the accelerometer includes a modulator configured to receive the optical signal, generate a modulated optical signal responsive to receiving the optical signal, and output the modulated optical signal to the resonator. A photoreceiver receives a passed optical signal from the resonator, where the passed optical signal indicates a resonance frequency of the resonator. Additionally, the photoreceiver receives a reflected optical signal from the resonator. The photoreceiver generates one or more electrical signals based on the passed optical signal and the reflected optical signal. Processing circuitry generates the error signal and determines the acceleration based on the one or more electrical signals.

According to one embodiment, a sensor includes a first detection element, and a processing part. The first detection element includes a base body, a first supporter fixed to the base body, a first movable part, first and second counter conductive parts. The first movable part is supported by the first supporter and separated from the base body. The first movable part includes a first movable base part supported by the first supporter, a second movable base part connected with the first movable base part, a first movable beam including a first beam, and a second movable beam including a second beam. The first beam includes a first end portion and a first other end portion. The second beam includes a second end portion and a second other end portion. The first counter conductive part faces the first movable beam. The second counter conductive part faces the second movable beam.

Proposed is a home appliance which allows a reception space defined therein to be seen from the outside through a viewing window without opening a door. In the home appliance, the viewing window is mounted to a door, and when a user knocks on the door, a vibration detection signal corresponding to vibration generated by the user’s knock is processed so as to accurately determine whether there is the vibration by the knock. Moreover, when the vibration generated by the knock is detected, the inside of the reception space is illuminated such that the inside of the reception space can be seen from the outside through the viewing window. Therefore, the user can see the inside of the reception space by a simple movement even without opening the door.

Proposed is a home appliance which allows a reception space defined therein to be seen from the outside through a viewing window without opening a door. In the home appliance, the viewing window is mounted to a door, and when a user knocks on the door, a vibration detection signal corresponding to vibration generated by the user’s knock is processed so as to accurately determine whether there is the vibration by the knock. Moreover, when the vibration generated by the knock is detected, the inside of the reception space is illuminated such that the inside of the reception space can be seen from the outside through the viewing window. Therefore, the user can see the inside of the reception space by a simple movement even without opening the door.

A quartz crystal device includes a package, a pedestal, and a crystal element. The pedestal is disposed in the package. The crystal element is bonded to the pedestal at four points. An angle formed by a center line connecting midpoints of both short sides of the crystal element and a straight line connecting a center point of the center line and each of bonding points is 22° or more and 30° or less.

An accelerometer comprising: a frame; a first proof mass suspended from the frame by one or more flexures to move relative to the frame along a first axis; a first resonant element assembly fixed between the frame and the first proof mass, wherein movement of the proof mass along the first axis relative to the frame exerts a strain on the first resonant element that affects its resonant behaviour; a second proof mass suspended from the frame by one or more flexures to move relative to the frame along a second axis, a second resonant element assembly fixed between the frame and the second proof mass, wherein movement of the second proof mass along the second axis relative to the frame exerts a strain on the second resonant element that affects its resonant behaviour; wherein the second proof mass surrounds the first proof mass and the first resonant element assembly.

An accelerometer comprising: a frame; one or more proof masses suspended from the frame by one or more flexures and movable relative to the frame along a sensing axis; a resonant element assembly, the resonant element assembly comprising a first resonant element and a second resonant element coupled to one another, the first resonant element connected between the one or more proof masses and the frame, the second resonant element connected between the one or more proof masses and the frame, such that movement of the one or more proof masses relative to the frame along the sensing axis results in one of the first and second resonant elements undergoing compression and the other of the first and second resonant elements undergoing tension; and drive circuitry configured to drive the resonant element assembly and a sensing circuit configured to determine a measure of acceleration.

An accelerometer comprising: a frame; one or more proof masses suspended from the frame by one or more flexures and movable relative to the frame along a sensing axis; a resonant element assembly, the resonant element assembly comprising a first resonant element and a second resonant element coupled to one another, the first resonant element connected between the one or more proof masses and the frame, the second resonant element connected between the one or more proof masses and the frame, such that movement of the one or more proof masses relative to the frame along the sensing axis results in one of the first and second resonant elements undergoing compression and the other of the first and second resonant elements undergoing tension; and drive circuitry configured to drive the resonant element assembly and a sensing circuit configured to determine a measure of acceleration.

An accelerometer comprising: a frame; one or more proof masses suspended from the frame by one or more flexures and movable relative to the frame along a sensing axis; a first resonant element fixed between an anchor on the frame and the one or more proof masses, and extending from the anchor to the one or more proof masses along the sensing axis; a second resonant element fixed between the anchor and the one or more proof masses and extending from the anchor to the one or more proof masses along the sensing axis in a opposite direction to the first resonant element.

An accelerometer comprising: a frame; one or more proof masses suspended from the frame by one or more flexures and movable relative to the frame along a sensing axis; a first resonant element fixed between an anchor on the frame and the one or more proof masses, and extending from the anchor to the one or more proof masses along the sensing axis; a second resonant element fixed between the anchor and the one or more proof masses and extending from the anchor to the one or more proof masses along the sensing axis in a opposite direction to the first resonant element.