A wearable display apparatus is provided. The wearable display apparatus includes: a substrate having first and second surfaces; a display component on the first surface; a surface acoustic wave transmission layer on the second surface; a surface acoustic wave input transducer configured to send out a first surface acoustic wave; a surface acoustic wave output transducer on the surface acoustic wave transmission layer, each surface acoustic wave output transducer and a corresponding surface acoustic wave input transducer being at an edge of the substrate to be adjacent to and spaced apart from each other, and each surface acoustic wave output transducer being configured to receive a second surface acoustic wave resulted from the first surface acoustic wave being transmitted and modulated by the surface acoustic wave transmission layer; and a control device, configured to control a target area of the display component to display.

A display apparatus comprises a display device including a display panel and a back cover on a rear surface of the display panel, and a curvature variation device at the back cover to vary a curvature of the display device, the curvature variation device may include an arc member at a rear region of the display device parallel to a first direction, a supporting plate at the rear region of the display device, a rotation driver on the supporting plate, a rectilinear driver on the supporting plate to perform a rectilinear motion, a rotation link part coupled to a center portion of the arc member on the supporting plate to rotate the center portion of the arc member based on a rectilinear motion of the rectilinear driver, and a holder part rotatably supporting the center portion of the arc member on the supporting plate.

A display apparatus comprises a display device including a display panel and a back cover on a rear surface of the display panel, and a curvature variation device at the back cover to vary a curvature of the display device, the curvature variation device may include an arc member at a rear region of the display device parallel to a first direction, a supporting plate at the rear region of the display device, a rotation driver on the supporting plate, a rectilinear driver on the supporting plate to perform a rectilinear motion, a rotation link part coupled to a center portion of the arc member on the supporting plate to rotate the center portion of the arc member based on a rectilinear motion of the rectilinear driver, and a holder part rotatably supporting the center portion of the arc member on the supporting plate.

An ultrasonic sensor includes: a first electrode that is provided in an ultrasonic microphone including a vibration element having a function of performing conversion between mechanical vibration and an electrical signal; a second electrode that is provided at a position different from the first electrode in an in-plane direction intersecting a directional axis of the ultrasonic microphone; and a detection section that is provided to detect the presence or absence of attached matter attached to the ultrasonic sensor on the basis of a change in capacitance between the first electrode and the second electrode.

An ultrasonic sensor includes: a first electrode that is provided in an ultrasonic microphone including a vibration element having a function of performing conversion between mechanical vibration and an electrical signal; a second electrode that is provided at a position different from the first electrode in an in-plane direction intersecting a directional axis of the ultrasonic microphone; and a detection section that is provided to detect the presence or absence of attached matter attached to the ultrasonic sensor on the basis of a change in capacitance between the first electrode and the second electrode.

A piezoelectric sound component is provided that includes a piezoelectric diaphragm and a case. The piezoelectric diaphragm is accommodated in the case. Moreover, a diaphragm 10 has a peripheral portion that includes a first peripheral portion and a second peripheral portion. The first peripheral portion is fixed to the case and the second peripheral portion is movable relative to the case. The case includes a step that is in positional agreement with the second peripheral portion in the thickness direction of the diaphragm. The step and the second peripheral portion define a clearance therebetween.

A piezoelectric sound component is provided that includes a piezoelectric diaphragm and a case. The piezoelectric diaphragm is accommodated in the case. Moreover, a diaphragm 10 has a peripheral portion that includes a first peripheral portion and a second peripheral portion. The first peripheral portion is fixed to the case and the second peripheral portion is movable relative to the case. The case includes a step that is in positional agreement with the second peripheral portion in the thickness direction of the diaphragm. The step and the second peripheral portion define a clearance therebetween.

A vibration apparatus, an apparatus including the same, and a vehicular apparatus including the new vibration apparatus are provided having a simplified structure. The vibration apparatus includes a vibration portion, a first electrode portion at a first surface of the vibration portion and configured with a conductive adhesive member, and a second electrode portion at a second surface different from the first surface of the vibration portion.

A vibration apparatus, an apparatus including the same, and a vehicular apparatus including the new vibration apparatus are provided having a simplified structure. The vibration apparatus includes a vibration portion, a first electrode portion at a first surface of the vibration portion and configured with a conductive adhesive member, and a second electrode portion at a second surface different from the first surface of the vibration portion.

Circuitry for estimating a displacement of a piezoelectric transducer in response to a drive signal applied to the piezoelectric transducer, the circuitry comprising: monitoring circuitry configured to be coupled to the piezoelectric transducer and to output a sense signal indicative of an electrical signal associated with the piezoelectric transducer as a result of the drive signal; wherein the circuitry is configured to generate a difference signal based on the drive signal and the sense signal; and wherein the circuitry further comprises processing circuitry configured to apply at least one transfer function to the difference signal to generate a signal indicative of the displacement of the piezoelectric transducer.