Abstract: Apparatuses, systems, and methods are provided for ultrasonic fingerprint sensors that are able to be used to detect fingerprints from opposing sides of an apparatus, e.g., a smartphone with screens on both sides of the housing. Some implementations of such sensors may include, for example, two piezoelectric and sensor pixel layer assemblies coupled to a common controller. Other implementations of such sensors may include, for example, a single piezoelectric and sensor pixel assembly coupled with a controller configured to apply a range-gate delay to obtain fingerprint scans from either opposing side of an apparatus. Yet further implementations of such sensors may include acoustic masking layers to spatially filter ultrasonic waves propagating to either side of an apparatus.

Abstract: An apparatus includes an ultrasonic sensor stack, a foldable display stack that includes a display stiffener, and an additional stiffener between the ultrasonic sensor stack and the foldable display stack. The additional stiffener forms an acoustic resonator with the display stiffener and an adhesive layer between the display stiffener and the additional stiffener in order to amplify transmission of ultrasonic waves transmitted by the ultrasonic sensor stack. The additional stiffener includes a material having a high modulus of elasticity, low density, and high acoustic impedance value. In some cases, the additional stiffener includes a metal, a ceramic, a glass, or a glass ceramic. The additional stiffener increases an overall stiffness and mechanical integrity of the apparatus so that a foam backer may be omitted from the ultrasonic sensor stack.

Abstract: Methods, devices and systems for providing extended reality effects are disclosed. In some examples, a control system may control a structure to provide extended reality effects and also may control an ultrasound-based haptic system to create haptic effects via transmitted ultrasonic waves. The ultrasound-based haptic system may include one or more arrays of ultrasonic transducers, such as piezoelectric micromachined ultrasonic transducers (PMUTs), mounted in or on the structure. The haptic effects may be created via air-coupled ultrasonic waves.

Abstract: An apparatus may include an ultrasonic sensor stack, a foldable display stack and a transmission enhancement layer. The foldable display stack may include a display stiffener and display stack layers. The display stack layers may form one or more display stack resonators configured to enhance ultrasonic waves transmitted by the ultrasonic sensor stack in a first ultrasonic frequency range. In some implementations, a transmission enhancement resonator may include the display stiffener and the transmission enhancement layer. In some examples, the transmission enhancement resonator may include at least a portion of the ultrasonic sensor stack. The transmission enhancement resonator may be configured to enhance the ultrasonic waves transmitted by the ultrasonic sensor stack in the first ultrasonic frequency range.

Abstract: Some disclosed implementations include an ultrasonic sensor stack and an acoustic resonator. The acoustic resonator may be configured to enhance ultrasonic waves transmitted by the ultrasonic sensor stack in an ultrasonic frequency range that is suitable for ultrasonic fingerprint sensors. In some examples, the acoustic resonator may include one or more low-impedance layers residing between a first higher-impedance layer and a second higher-impedance layer. Each of the one or more low-impedance layers may have a lower acoustic impedance than an acoustic impedance of the first higher-impedance layer or an acoustic impedance of the second higher-impedance layer. At least one low-impedance layer may have a thickness corresponding to a multiple of a half wavelength at a peak frequency of the acoustic resonator. The peak frequency may be within a frequency range from 1 MHz. to 20 MHz.

Abstract: An apparatus may include an ultrasonic sensor stack, a foldable display stack and a transmission enhancement layer. The foldable display stack may include a display stiffener and display stack layers. The display stack layers may form one or more display stack resonators configured to enhance ultrasonic waves transmitted by the ultrasonic sensor stack in a first ultrasonic frequency range. In some implementations, a transmission enhancement resonator may include the display stiffener and the transmission enhancement layer. In some examples, the transmission enhancement resonator may include at least a portion of the ultrasonic sensor stack. The transmission enhancement resonator may be configured to enhance the ultrasonic waves transmitted by the ultrasonic sensor stack in the first ultrasonic frequency range.

Abstract: Some disclosed implementations include an ultrasonic sensor stack and an acoustic resonator. The acoustic resonator may be configured to enhance ultrasonic waves transmitted by the ultrasonic sensor stack in an ultrasonic frequency range that is suitable for ultrasonic fingerprint sensors. In some examples, the acoustic resonator may include one or more low-impedance layers residing between a first higher-impedance layer and a second higher-impedance layer. Each of the one or more low-impedance layers may have a lower acoustic impedance than an acoustic impedance of the first higher-impedance layer or an acoustic impedance of the second higher-impedance layer. At least one low-impedance layer may have a thickness corresponding to a multiple of a half wavelength at a peak frequency of the acoustic resonator. The peak frequency may be within a frequency range from 1 MHz. to 20 MHz.

Abstract: An apparatus may include an ultrasonic sensor stack, a foldable display stack and a transmission enhancement layer. The foldable display stack may include a display stiffener and display stack layers. The display stack layers may form one or more display stack resonators configured to enhance ultrasonic waves transmitted by the ultrasonic sensor stack in a first ultrasonic frequency range. In some implementations, a transmission enhancement resonator may include the display stiffener and the transmission enhancement layer. In some examples, the transmission enhancement resonator may include at least a portion of the ultrasonic sensor stack. The transmission enhancement resonator may be configured to enhance the ultrasonic waves transmitted by the ultrasonic sensor stack in the first ultrasonic frequency range.

Abstract: Some disclosed devices may include a display stack, a cover layer proximate a first side of the display stack and a segmented transducer array proximate a second side of the display stack. The segmented transducer array may include a plurality of separate transducer segments. Each of the separate transducer segments may include a piezoelectric layer and a thin-film transistor (TFT) layer. The separate transducer segments may include transmitter transducer segments and receiver transducer segments. In some examples, a spacing between at least a first plurality of the transmitter transducer segments may correspond to a display stack and cover layer oscillation mode frequency in a range from 20 Hz to 20 kHz, from 15 kHz to 200 kHz or from 20 kHz to 400 kHz.

Abstract: Techniques for operating an ultrasonic sensor array, the ultrasonic sensor array disposed under a platen, include making a determination whether or not to recalibrate the ultrasonic sensor array based on whether a first screen protector disposed above the platen has been removed or replaced by a second screen protector; and recalibrating the ultrasonic sensor array, when the determination is to recalibrate the ultrasonic sensor array. In some cases, the techniques include prompting a user to indicate whether or not the screen protector has been changed or removed, and recalibrating the ultrasonic sensor array only after confirmation from the user.

Abstract: Disclosed are methods, devices, apparatuses, and systems for an under-display ultrasonic fingerprint sensor. A display device may include a platen, a display underlying the platen, and an ultrasonic fingerprint sensor underlying the display, where the ultrasonic fingerprint sensor is configured to transmit and receive ultrasonic waves via an acoustic path through the platen and the display. A light-blocking layer and/or an electrical shielding layer may be provided between the ultrasonic fingerprint sensor and the display, where the light-blocking layer and/or the electrical shielding layer are in the acoustic path. A mechanical stress isolation layer may be provided between the ultrasonic fingerprint sensor and the display, where the mechanical stress isolation layer is in the acoustic path.

Abstract: Apparatuses, systems, and methods are provided for ultrasonic fingerprint sensors that are able to be used to detect fingerprints from opposing sides of an apparatus, e.g., a smartphone with screens on both sides of the housing. Some implementations of such sensors may include, for example, two piezoelectric and sensor pixel layer assemblies coupled to a common controller. Other implementations of such sensors may include, for example, a single piezoelectric and sensor pixel assembly coupled with a controller configured to apply a range-gate delay to obtain fingerprint scans from either opposing side of an apparatus. Yet further implementations of such sensors may include acoustic masking layers to spatially filter ultrasonic waves propagating to either side of an apparatus.

Abstract: Some disclosed implementations include an ultrasonic sensor stack and an acoustic resonator. The acoustic resonator may be configured to enhance ultrasonic waves transmitted by the ultrasonic sensor stack in an ultrasonic frequency range that is suitable for ultrasonic fingerprint sensors. In some examples, the acoustic resonator may include one or more low-impedance layers residing between a first higher-impedance layer and a second higher-impedance layer. Each of the one or more low-impedance layers may have a lower acoustic impedance than an acoustic impedance of the first higher-impedance layer or an acoustic impedance of the second higher-impedance layer. At least one low-impedance layer may have a thickness corresponding to a multiple of a half wavelength at a peak frequency of the acoustic resonator. The peak frequency may be within a frequency range from 1 MHz. to 20 MHz.

Abstract: Some disclosed implementations include an ultrasonic sensor stack and an acoustic resonator. The acoustic resonator may be configured to enhance ultrasonic waves transmitted by the ultrasonic sensor stack in an ultrasonic frequency range that is suitable for ultrasonic fingerprint sensors. In some examples, the acoustic resonator may include one or more low-impedance layers residing between a first higher-impedance layer and a second higher-impedance layer. Each of the one or more low-impedance layers may have a lower acoustic impedance than an acoustic impedance of the first higher-impedance layer or an acoustic impedance of the second higher-impedance layer. At least one low-impedance layer may have a thickness corresponding to a multiple of a half wavelength at a peak frequency of the acoustic resonator. The peak frequency may be within a frequency range from 1 MHz. to 20 MHz.

Abstract: An apparatus may include an ultrasonic sensor stack, a foldable display stack and a transmission enhancement layer. The foldable display stack may include a display stiffener and display stack layers. The display stack layers may form one or more display stack resonators configured to enhance ultrasonic waves transmitted by the ultrasonic sensor stack in a first ultrasonic frequency range. In some implementations, a transmission enhancement resonator may include the display stiffener and the transmission enhancement layer. In some examples, the transmission enhancement resonator may include at least a portion of the ultrasonic sensor stack. The transmission enhancement resonator may be configured to enhance the ultrasonic waves transmitted by the ultrasonic sensor stack in the first ultrasonic frequency range.

Abstract: Apparatuses, systems, and methods are provided for ultrasonic fingerprint sensors that are able to be used to detect fingerprints from opposing sides of an apparatus, e.g., a smartphone with screens on both sides of the housing. Some implementations of such sensors may include, for example, two piezoelectric and sensor pixel layer assemblies coupled to a common controller. Other implementations of such sensors may include, for example, a single piezoelectric and sensor pixel assembly coupled with a controller configured to apply a range-gate delay to obtain fingerprint scans from either opposing side of an apparatus. Yet further implementations of such sensors may include acoustic masking layers to spatially filter ultrasonic waves propagating to either side of an apparatus.

Abstract: Apparatuses, systems, and methods are provided for ultrasonic fingerprint sensors that are able to be used to detect fingerprints from opposing sides of an apparatus, e.g., a smartphone with screens on both sides of the housing. Some implementations of such sensors may include, for example, two piezoelectric and sensor pixel layer assemblies coupled to a common controller. Other implementations of such sensors may include, for example, a single piezoelectric and sensor pixel assembly coupled with a controller configured to apply a range-gate delay to obtain fingerprint scans from either opposing side of an apparatus. Yet further implementations of such sensors may include acoustic masking layers to spatially filter ultrasonic waves propagating to either side of an apparatus.

Abstract: Some disclosed devices may include a display stack, a cover layer proximate a first side of the display stack and a segmented transducer array proximate a second side of the display stack. The segmented transducer array may include a plurality of separate transducer segments. Each of the separate transducer segments may include a piezoelectric layer and a thin-film transistor (TFT) layer. The separate transducer segments may include transmitter transducer segments and receiver transducer segments. In some examples, a spacing between at least a first plurality of the transmitter transducer segments may correspond to a display stack and cover layer oscillation mode frequency in a range from 20 Hz to 20 kHz, from 15 kHz to 200 kHz or from 20 kHz to 400 kHz.

Abstract: An ultrasonic sensor array includes a plurality of ultrasonic transducers, each transducer including a piezoelectric member. Each of the transducers includes an electret member, a receive (Rx) layer configured to exhibit a first d33 resonating mode coefficient and a transmit (Tx) layer configured to exhibit a second d33 resonating mode coefficient, the first coefficient being different from the second coefficient. The transducers are disposed on a flexible substrate.

Abstract: An apparatus may include an ultrasonic sensor system having an ultrasonic transceiver layer, a thin-film transistor (TFT) layer and a frequency-differentiating layer. In some examples, the frequency-differentiating layer may include a first frequency-differentiating layer area corresponding to a lower-frequency area of the ultrasonic sensor system. The first frequency-differentiating layer area may include a first material having a first acoustic impedance. In some such examples, the frequency-differentiating layer may include a second frequency-differentiating layer area corresponding to a higher-frequency area of the ultrasonic sensor system. The second frequency-differentiating layer area may include a second material having a second acoustic impedance. The first acoustic impedance may, for example, be higher than the second acoustic impedance.