Provided is a directional acoustic sensor. The acoustic sensor includes a support a plurality of resonators provided on the support, and extending in a length direction. Each resonator of the plurality of resonators may include a base; and a frame provided on the base and extending continuously along a length of the base in the length direction. The base may have a thickness less than that of the frame.

Provided is a directional acoustic sensor. The acoustic sensor includes a support a plurality of resonators provided on the support, and extending in a length direction. Each resonator of the plurality of resonators may include a base; and a frame provided on the base and extending continuously along a length of the base in the length direction. The base may have a thickness less than that of the frame.

A method for manufacturing a piezoelectric device that includes a substrate and a vibration portion that can include a membrane or a beam that is directly or indirectly supported by the substrate and arranged above the substrate. Moreover, the vibration portion includes a piezoelectric layer and the method includes forming the vibration portion and adjusting a resonance frequency of the vibration portion by locally subjecting a region including the vibration portion to heat treatment.

A method for manufacturing a piezoelectric device that includes a substrate and a vibration portion that can include a membrane or a beam that is directly or indirectly supported by the substrate and arranged above the substrate. Moreover, the vibration portion includes a piezoelectric layer and the method includes forming the vibration portion and adjusting a resonance frequency of the vibration portion by locally subjecting a region including the vibration portion to heat treatment.

Low frequency alarm tones emitted by life safety devices are more like to notify sleeping children and the elderly. Disclosed herein is a life safety device equipped with a novel, compact, quarter-wave, folded resonant cavity which significantly increases the low frequency (400-700 Hz square wave) acoustic efficiency of an audio output transducer when the folded resonant cavity is acoustically coupled to the transducer forming an audio output apparatus. The folded resonant cavity is comprised of undulating, annular, acoustic passages to significantly reduce the length of the resonant cavity, thereby permitting the audio output apparatus to fit within the housing of conventional size life safety devices such as, but not limited to, residential and commercial smoke alarms and carbon monoxide alarms. Battery powered embodiments of the audio output apparatus comprising a folded resonant cavity passed audibility tests for low frequency alarm tones in smoke alarms specified by UL217.

Low frequency alarm tones emitted by life safety devices are more like to notify sleeping children and the elderly. Disclosed herein is a life safety device equipped with a novel, compact, quarter-wave, folded resonant cavity which significantly increases the low frequency (400-700 Hz square wave) acoustic efficiency of an audio output transducer when the folded resonant cavity is acoustically coupled to the transducer forming an audio output apparatus. The folded resonant cavity is comprised of undulating, annular, acoustic passages to significantly reduce the length of the resonant cavity, thereby permitting the audio output apparatus to fit within the housing of conventional size life safety devices such as, but not limited to, residential and commercial smoke alarms and carbon monoxide alarms. Battery powered embodiments of the audio output apparatus comprising a folded resonant cavity passed audibility tests for low frequency alarm tones in smoke alarms specified by UL217.

This disclosure provides some implementations of systems, methods and apparatus associated with a drive scheme for ultrasonic transducer pixel readout. In some implementations, a piezoelectric ultrasonic transducer has a first electrode, a second electrode, and a piezoelectric layer disposed between the first and second electrodes. The second electrode is coupled with a sampling node. A sampling diode has an input and an output. The input is coupled to receive a diode bias signal. The output is coupled with the sampling node. Controller circuitry is configured to control the diode bias signal to at least partially drive a voltage at the sampling node. Read circuitry is coupled with the sampling node to read the voltage.

Disclosed is an acoustic transducer for converting a sound signal into an electric signal, including a mobile element movable under the effect of the sound signal, a fixed element opposite the mobile element, a recess, and a dissipative element between the mobile and fixed elements. The coupled system has a natural frequency corresponding to a resonance frequency of the transducer set at maximum sensitivity. The mobile element, the fixed element, the dissipative element and the recess are configured so the quality factor of the acoustic transducer>2. The recess has a straight prismatic, cylindrical, or frustoconical shape, the mobile element forming a first base of the prism, cylinder, or frustum, the fixed element being inside the prism, cylinder or frustum, over the second base of the prism, cylinder or frustum. Such a transducer also incorporates an analogue filtering function for filtering the signal around the natural frequency of same.

An information handling system includes an outer housing and a processor and a memory disposed in the outer housing. The processor is configured to execute instructions to process information. The memory is configured to store the information. The information handling system includes a piezoelectric transducer disposed in the outer housing and mechanically coupled to a surface held by the outer housing. The information handling system includes a sensor disposed in the outer housing and configured to generate an indicator of user presence in a zone proximate to the piezoelectric transducer and above a second side of the surface. The information handling system includes a controller disposed in the outer housing and coupled to the memory. The controller is configured to selectively configure the piezoelectric transducer to be responsive to a first subsystem or to be responsive to a second subsystem according to the indicator of user presence.

An information handling system includes an outer housing and a processor and a memory disposed in the outer housing. The processor is configured to execute instructions to process information. The memory is configured to store the information. The information handling system includes a piezoelectric transducer disposed in the outer housing and mechanically coupled to a surface held by the outer housing. The information handling system includes a sensor disposed in the outer housing and configured to generate an indicator of user presence in a zone proximate to the piezoelectric transducer and above a second side of the surface. The information handling system includes a controller disposed in the outer housing and coupled to the memory. The controller is configured to selectively configure the piezoelectric transducer to be responsive to a first subsystem or to be responsive to a second subsystem according to the indicator of user presence.