Aspects of the disclosure relate to using a display as a sound emitter and may relate to an electronic device including a display. In particular a vibration sensor such as an accelerometer is physically coupled to the display and senses display vibration to provide a high accuracy feedback loop with respect to representing actual audio output from the display. The electronic device includes an actuator physically coupled to the display and configured to cause vibration of the display in response to an audio signal. The electronic device further includes a vibration sensor physically coupled to the display and configured to output a vibration sensor signal proportional to the vibration of the display due to the actuator. The electronic device further includes a processor operably coupled to the vibration sensor. The processor is configured to adjust the audio signal based on the vibration sensor signal from the vibration sensor.

The polymer film of the present invention has through holes extending from one principal surface of the polymer film to the other principal surface of the polymer film. The through holes are straight holes having a central axis extending straight, and have a shape in which the area of a cross-section perpendicular to the direction of the central axis increases from the one principal surface of the polymer film toward the other principal surface. This polymer film has passages in its thickness direction, has an unconventional structure, and can be used in various applications, such as in a waterproof sound-permeable membrane, in a waterproof gas-permeable membrane, and in a suction sheet. The ratio a/b of the opening diameter a of the through holes at the one principal surface to the opening diameter b of the through holes at the other principal surface is 80% or is less than 80%.

The polymer film of the present invention has through holes extending from one principal surface of the polymer film to the other principal surface of the polymer film. The through holes are straight holes having a central axis extending straight, and have a shape in which the area of a cross-section perpendicular to the direction of the central axis increases from the one principal surface of the polymer film toward the other principal surface. This polymer film has passages in its thickness direction, has an unconventional structure, and can be used in various applications, such as in a waterproof sound-permeable membrane, in a waterproof gas-permeable membrane, and in a suction sheet. The ratio a/b of the opening diameter a of the through holes at the one principal surface to the opening diameter b of the through holes at the other principal surface is 80% or is less than 80%.

An ultrasonic transducer including a membrane film and a perforated baseplate. The baseplate can have a conductive surface with a plurality of perforations formed through the baseplate. The membrane film can have a conductive surface and be positioned under tension proximate to the perforations formed through the baseplate. The tension of the membrane film can be controlled to provide a restoring force to counteract the moving mass of the membrane film, and the moving mass of air in the perforations of the baseplate. By selecting the diameter(s) of the perforations of the baseplate, the thickness of the baseplate, the thickness of the membrane film, the tension of the membrane film, and/or the bending stiffness of the membrane film, a wide bandpass frequency response of the ultrasonic transducer centered at an ultrasonic frequency of interest can be obtained and tailored to a desired application.

An ultrasonic transducer including a membrane film and a perforated baseplate. The baseplate can have a conductive surface with a plurality of perforations formed through the baseplate. The membrane film can have a conductive surface and be positioned under tension proximate to the perforations formed through the baseplate. The tension of the membrane film can be controlled to provide a restoring force to counteract the moving mass of the membrane film, and the moving mass of air in the perforations of the baseplate. By selecting the diameter(s) of the perforations of the baseplate, the thickness of the baseplate, the thickness of the membrane film, the tension of the membrane film, and/or the bending stiffness of the membrane film, a wide bandpass frequency response of the ultrasonic transducer centered at an ultrasonic frequency of interest can be obtained and tailored to a desired application.

A vibration membrane is disclosed. The vibration membrane includes a central dome part and a suspension part surrounding the dome part. The suspension part includes a pair of long-axis parts parallel to a long axis of the vibration membrane, a pair of short-axis parts parallel to a short axis of the vibration membrane, and a number of corner parts connecting the long-axis parts with the short-axis parts. The suspension part further includes first reinforcing parts located on the corner parts and second reinforcing parts located on the long-axis parts. Each of the second reinforcing part has a first master extension part and a first slave extension part crossing with the first master extension part. By virtue of the configuration, the strength of the vibration membrane is improved.

A vibration membrane is disclosed. The vibration membrane includes a central dome part and a suspension part surrounding the dome part. The suspension part includes a pair of long-axis parts parallel to a long axis of the vibration membrane, a pair of short-axis parts parallel to a short axis of the vibration membrane, and a number of corner parts connecting the long-axis parts with the short-axis parts. The suspension part further includes first reinforcing parts located on the corner parts and second reinforcing parts located on the long-axis parts. Each of the second reinforcing part has a first master extension part and a first slave extension part crossing with the first master extension part. By virtue of the configuration, the strength of the vibration membrane is improved.

An ultrasonic sensor includes a housing encompassing a circumferential side wall. The ultrasonic sensor includes a transducer element to convert an incoming ultrasonic signal into a detectable electrical signal, or conversely, to convert an electrical signal into an ultrasonic signal to be emitted. The ultrasonic sensor includes an oscillatable diaphragm connected to the housing. A multitude of mass elements are situated on a surface of the diaphragm. Alternatively or in addition, a multitude of mass elements are situated within the diaphragm. The mass elements form an acoustic meta material, which is a stop band material, band gap material or phononic crystal and which has a resonant behavior within a frequency band. A resonance frequency of the diaphragm including the multitude of mass elements situated on and/or within the diaphragm is within the frequency band at which the mass elements exhibit a resonant behavior.

A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.

A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.