System with ultrasound sensor

Abstract

A user classification system is provided. The system includes a sensor for generating a sensor signal and a user device. The sensor is configured to generate a sensor signal, and the sensor includes a controller. The controller is configured to: provide a drive signal to be transmitted as an ultrasonic pulse by the sensor; and receiving and processing the signal recorded by the sensor. The signal recorded by the sensor includes one or more reflections of the recorded ultrasonic pulse transmitted by the sensor. The system classifies users of the system based on the sensor signals.

Description

[0001] Related Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 451,368 (Docket No. ORC-011-PR1), filed on March 10, 2023, entitled “System with Ultrasound Sensor,” the contents of which are hereby incorporated by reference in their entirety for all purposes.

[0003] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 605,732 (Docket No. ORC-011-PR2), filed on December 4, 2023, entitled “System with Ultrasound Sensor,” the contents of which are hereby incorporated by reference in their entirety for all purposes.

[0004] This application is related to U.S. Provisional Patent Application Serial No. 63 / 140,647 (Docket No. ORC-003-PR) filed on January 22, 2021, entitled “Ultrasound Signal-Processing System and Associated Methods,” and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0005] This application is related to U.S. Provisional Patent Application Serial No. 63 / 174,516 (Docket No. ORC-004-PR) filed on April 13, 2021, entitled “Multi-Platen Ultrasound Fingerprint Sensors and Associated Methods,” and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0006] This application is related to U.S. Provisional Patent Application Serial No. 63 / 189,567 (Docket No. ORC-005-PR1) filed on May 17, 2021, entitled “System Including User Classification,” and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0007] This application is related to U.S. Provisional Patent Application Serial No. 63 / 242,657 (Docket No. ORC-005-PR2) filed on September 10, 2021, entitled “System Including UserClassification,” and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0008] This application is related to the international PCT patent application serial number PCT / US22 / 013299 (file number ORC-005-PCT) entitled “System with Ultrasound Sensor” filed on January 21, 2022 (publication date July 28, 2022, publication number WO 2022 / 159692), and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0009] This application is related to U.S. patent application serial number 18 / 272,965 (docket number ORC-005-US) filed on July 18, 2023, entitled “System with Ultrasound Sensor” (publication date ____________, publication number ____________), and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0010] This application is related to U.S. Provisional Patent Application Serial No. 62 / 753,305 (Docket No. ORC-006-PR), entitled “Passwordless Authentication,” filed on October 31, 2018, the contents of which are incorporated by reference in their entirety for all purposes.

[0011] This application is related to the international PCT patent application serial number PCT / US19 / 059248 (file number ORC-006-PCT) entitled “Passwordless Authentication Systems and Methods” filed on October 31, 2019 (publication date May 7, 2020, publication number WO 2020 / 092832), and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0012] This application is related to U.S. national phase application serial number 17 / 290,740 (docket number ORC-006-US) filed on April 30, 2021, entitled “Passwordless Authentication Systems and Methods” (publication date January 6, 2022, publication number US2022 / 0004617), and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0013] This application is related to U.S. Provisional Patent Application Serial No. 63 / 123,950 (Docket No. ORC-007-PR1) filed on December 10, 2020, entitled “Authentication Witness Systems and Methods,” and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0014] This application is related to the international PCT patent application serial number PCT / US21 / 062809 (file number ORC-007-PCT) entitled “Systems and Methods Including User Authentication” filed on December 10, 2021 (publication date June 16, 2022, publication number WO2022 / 0125898), and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0015] This application is related to U.S. national phase application serial number 18 / 039,364 (docket number ORC-007-US) entitled “Systems and Methods Including User Authentication” filed on May 30, 2023 (publication number US2023 / 0350999, publication date November 2, 2023; U.S. Patent No. 11,934,508, promulgation date March 19, 2024), and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0016] This application is related to U.S. continuation application serial number 18 / 424,943 (docket number ORC-007-US-CON1) (publication date ____________, publication number US____________), entitled “Systems and Methods Including User Authentication”, filed on January 29, 2024, and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0017] This application is related to U.S. Provisional Patent Application Serial No. 63 / 351,635 (Docket No. ORC-009-PR1), filed on June 13, 2022, entitled “Systems and Methods That Provide a High Level of Security for a User,” and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0018] This application is related to the international PCT patent application serial number PCT / US23 / 025196 (file number ORC-009-PCT) entitled “Systems and Methods That Provide a High Level of Security for a User” filed on June 13, 2023 (publication date December 21, 2023, publication number WO2023 / 244602), and the contents of the above application are incorporated by reference in their entirety for all purposes.

[0019] Invention concept field

[0020] Embodiments disclosed herein generally relate to systems including one or more ultrasonic sensors, such as for receiving commands from a user or identifying or assessing a condition of a user. Background Art

[0021] Many commercial devices include sensors for collecting user information. These systems may include user identification capabilities, such as the ability to identify a user via fingerprint or facial recognition. Improved systems, devices, and methods are needed for classifying users of a system. Summary of the invention

[0022] According to one aspect of the present inventive concept, a user classification system includes a sensor configured to generate a sensor signal. The sensor includes a controller configured to: provide a drive signal to be transmitted by the sensor as an ultrasonic pulse; and receive and process a signal recorded by the sensor. The signal recorded by the sensor includes one or more recorded reflections of the ultrasonic pulse transmitted by the sensor. The system is configured to classify a user of the user device based on the sensor signal.

[0023] In some embodiments, the controller is configured to implement a beamforming technique. The beamforming technique may include time domain beamforming. The beamforming technique may include frequency domain beamforming. The frequency domain beamforming may be implemented by oversampling the recorded signal. The frequency domain beamforming may be implemented using IQ sampling. The controller may include an IQ demodulator.

[0024] In some embodiments, the sensor further comprises a first ultrasound layer. The user device may further comprise a display, and the first ultrasound layer may be located at a lower side of the display. The sensor may further comprise a second ultrasound layer, and the second ultrasound layer may be located at the lower side of the display. The first ultrasound layer may comprise a boundary, and the controller may be located outside the boundary. The first ultrasound film layer may comprise a piezoelectric material. The piezoelectric material may comprise PVDF. The piezoelectric material may comprise a 0-3 type piezoelectric composite material.

[0025] In some embodiments, the controller includes one or more thin film transistor components.

[0026] In some embodiments, the controller includes one or more resonant circuits configured to increase the transmission pressure of the sensor.

[0027] In some embodiments, the sensor includes a substrate and one or more ultrasound film layers, and the user device includes a display, and the one or more ultrasound film layers are located between the substrate and the display.

[0028] In some embodiments, the sensor is fabricated using a layered deposition process.

[0029] In some embodiments, the sensor is manufactured with reference to the description in the specification and drawings herein.

[0030] In some embodiments, the sensor includes two or more sensors.The sensor may include a first sensor and a second sensor, and the construction and arrangement of the second sensor may be different from that of the first sensor.

[0031] In some embodiments, the system further comprises a processing unit comprising a processor and a memory storage component coupled to the processor, and the memory storage component stores instructions for the processor to execute an algorithm. The algorithm may include a weighting factor and / or bias for selecting one user identification in preference to another user identification. The sensor may include an array of pixel elements, and the algorithm may include an artificial intelligence algorithm and / or other algorithm that may be configured to determine which subset of pixel elements in the array of pixel elements can be used to image a fingerprint or other object. The algorithm may be configured to compensate for damage to a housing or other portion of the sensor. The user device may include a housing and a covering surrounding at least a portion of the housing, and the algorithm may be configured to adjust the covering.

[0032] In some embodiments, the sensor is configured to provide multi-cycle ultrasound signal bursts.

[0033] In some embodiments, the user device includes a user interface including a display, and the sensor is located below the display.

[0034] In some embodiments, the user device includes a housing, and the sensor is constructed and arranged to send and / or receive ultrasonic signals through at least a portion of the housing. At least a portion of the housing may include a metal having a thickness of at least 100 μm, no more than 5 mm, or both. At least a portion of the housing may include an edge of the housing and / or a side of the housing. The sensor may include a first sensor disposed near a first edge of the housing and a second sensor disposed near a second edge of the housing. The first sensor may be constructed and arranged differently from the second sensor. The user device may include a button and / or other user control portion, and the sensor may be located near the button and / or other user control portion. The housing may include aluminum, titanium, and / or other metals. The sensor may include a substrate, and the substrate may be attached to the housing. The thickness of the substrate may be equal to nλ / 2±λ / 4, where λ may be set by the operating frequency of the sensor and the speed of sound in the material of the substrate. The substrate may include an insulating material. The substrate may be configured as an acoustic matching layer between the sensor and the housing. The sensor may include row electrodes and column electrodes, and the thickness of the substrate may be no less than the spacing between the row electrodes and the column electrodes.

[0035] In some embodiments, the system includes a calibration routine.The user device may include a housing and a cover surrounding at least a portion of the housing, and the calibration routine may be configured to compensate for the presence of the cover.

[0036] In some embodiments, the system is configured to record fingerprints from multiple different fingers, and the system is configured to assign the use of each fingerprint to a different set of instructions executed by the user device. The instruction set can be configured to perform a function of the user device selected from the group consisting of: transitioning from a locked state to an unlocked state; transitioning from an unlocked state to a locked state; causing a screen of a user interface to go blank or otherwise change state; dialing a specific person's phone number; entering an alarm state; dialing 911; entering a specific software program; and combinations thereof. Different fingerprints can be independently associated with the task of unlocking a device with an associated user permission level.

[0037] In some embodiments, the user device is configured to operate in a detection mode and enter an imaging mode when the presence of a finger is detected, the detection mode being configured to detect when a finger is placed on the sensor and / or otherwise close to the sensor, and the imaging mode being configured to image a fingerprint or other object. The power consumption of the user device in the detection mode may be lower than that in the imaging mode. The user device may be configured to switch back to the detection mode after capturing the fingerprint. The detection mode may be configured to operate at a frame rate of at least 5fps. The sensor may have a transmitting channel and a receiving channel, and the detection mode may use fewer transmitting channels and / or receiving channels than the imaging mode.

[0038] In some embodiments, the user device is configured to measure an average signal reduction across the surface of the sensor. The measurement of the average signal reduction can be used to determine the position of a finger placed on the sensor. The sensor can be configured to provide a writing tablet function. The sensor can be configured to control a cursor of the user device.

[0039] In some embodiments, the sensor is configured to detect various gestures of the user. The various gestures may include: tapping; double-clicking; and / or sliding in one or more directions. Detection of a particular gesture may be configured to perform a function selected from the group consisting of: locking the user device; unlocking the user device; adjusting the volume of the user device; minimizing and / or maximizing an application displayed on a user interface of the user device; adjusting the brightness of the user interface of the user device; and combinations thereof.

[0040] In some embodiments, the sensor includes an ultrasonic sensor and a capacitive sensor. The user device can be configured to operate in a detection mode, the detection mode can be configured to detect when a finger is placed on the sensor and / or otherwise close to the sensor, and when operating in the detection mode, both the capacitive sensor and the ultrasonic sensor are enabled. The user device can be configured to use the ultrasonic sensor and / or the capacitive sensor alone and / or in combination to: reduce power consumption; sensitize and / or otherwise increase the detection threshold; and / or enhance the user experience.

[0041] In some embodiments, the sensor includes a first sensor and a second sensor, and the user device is configured to allow and / or require the user to place a first finger on the first sensor and a second finger on the second sensor, with the first finger opposite the second finger, and to be able to capture at least a partial fingerprint image from each of the first finger and the second finger.

[0042] In some embodiments, the user device is configured to provide different levels of user identification. The different levels of user identification may include: a first, lower security level of identification based on a single fingerprint image; a second, more secure level of identification based on multiple fingerprint images recorded sequentially and / or simultaneously from one or more of the sensors; and / or a third, more secure level of identification based on multiple fingerprint images recorded simultaneously and / or sequentially from one or more sensors.

[0043] In some embodiments, the sensor includes a first sensor and a second sensor configured as a multi-platen sensor. The user device may include a housing, and a first portion of the housing near the first sensor and a second portion of the housing near the second sensor have different thicknesses. The system may also include a controller, and the controller may be configured to drive and / or sense the first sensor and the second sensor simultaneously.

[0044] In some embodiments, the system is configured to record a plurality of A-scans, and the system is further configured to perform image reconstruction without determining the temporal sequence of each A-scan.The system may be configured to determine only amplitude and phase.

[0045] In some embodiments, the system is configured to determine amplitude and phase information using IQ sampling.

[0046] In some embodiments, the user device includes a housing, and the sensor includes one or more non-square arrays, the one or more non-square arrays being close to the edge and / or side of the housing. Each of the one or more non-square arrays may include a rectangular array including a different number of transmit and receive channels. Each of the one or more non-square arrays may have a width of less than 2 mm, a length of at least 6 mm, or both.

[0047] In some embodiments, the sensor includes pixel elements of a first resolution, and the system is configured to reconstruct an image at a resolution higher than the first resolution using ultrasound beamforming. The sensor may include column electrodes and row electrodes, and a density of a set of focal points formed by the beamforming may be greater than a pitch of the column electrodes, greater than a pitch of the row electrodes, or both.

[0048] In some embodiments, the sensor includes pixel elements and one or more sparse ultrasound arrays, and each array is configured to use a sparse distribution of pixel elements.

[0049] In some embodiments, the sensor includes pixel elements, and the system is configured to compensate for one or more failed pixel elements using sparse array technology. The system can be configured to record images at a resolution of at least 500 dpi when 10% or more of the pixel elements fail. The system can be configured to record images at a resolution of at least 500 dpi when 20% or more, 30% or more, 40% or more, and / or 50% or more of the pixel elements fail.

[0050] In some embodiments, the sensor is configured to collect A-scans, and the sensor is further configured to process multiple discrete time samples for each A-scan. The sensor can be configured to process a single time sample for each pulse of the ultrasound signal, and average the results of each time sample to reconstruct the fingerprint image. The processed multiple discrete time samples can represent multiple A-scans based on each focus, which improves the signal-to-noise ratio of the reconstructed image.

[0051] In some embodiments, the system is configured to use ultrasound beamforming that is achieved by the number of control bits based on the phase resolution used. The system may be configured to achieve eight levels of phase resolution or less using a three-bit control system.

[0052] In some embodiments, the sensor includes multiple layers, and two or more of the multiple layers together include a thickness configured to establish acoustic resonance. The first layer of the two or more layers may include a substrate layer, the second layer of the two or more layers may include an electrode layer, and / or the third layer of the two or more layers may include a glue layer. The user device may include a housing, and the third layer including the glue layer may connect the sensor to the housing.

[0053] In some embodiments, the sensor comprises multiple layers, and one or more of the multiple layers are configured to reduce a resonant frequency of the sensor.

[0054] In some embodiments, the controller is further configured to provide a drive signal at an adjustable frequency. The controller may include a calibration routine configured to determine an optimized frequency of the drive signal provided to the sensor. The sensor may include two or more parts, and the calibration routine may be configured to independently calibrate the drive signal for one or more of the two or more parts. The calibration routine may be configured to optimize the drive signal based on the variability of one or more sensor parameters. The calibration routine may be configured to adjust the drive signal to adapt to one or more environmental factors. The one or more environmental factors may include temperature, humidity, or both. The sensor may also be configured to generate a signal related to temperature, and the calibration routine may adjust the drive signal based on the signal related to the temperature of the sensor.

[0055] In some embodiments, the sensor is optimized to operate within a temperature range, and the temperature range is within 10°C of body temperature. The controller can be configured to prevent user classification when the temperature of the sensor exceeds the temperature range. The user device can be configured to instruct the user to adjust the temperature of the sensor when the temperature of the sensor exceeds the temperature range. The system can be configured to provide a first level of authentication and a second level of authentication, wherein the first level of authentication may include a higher level of authentication than the second level of authentication, and the controller can be configured to prevent user classification with the first level of authentication when the temperature of the sensor exceeds the temperature range.

[0056] In some embodiments, the sensor includes one or more apodization portions, and the one or more apodization portions are configured to compensate for the natural focus of the sensor. The sensor may include row electrodes extending along the long dimension of the sensor and column electrodes extending along the short dimension of the sensor. The column electrodes may include a cone near the edge of the long dimension of the sensor, and the one or more apodization portions include the cone. Each of the row electrodes may include a width and an inter-electrode spacing, and the inter-electrode spacing may increase near the edge of the long dimension of the sensor, and / or the width of each electrode may decrease near the edge of the long dimension of the sensor, and the one or more apodization portions may include an increased inter-electrode spacing and / or a decreased electrode width.

[0057] In some embodiments, the sensor includes one or more receive channels, and the controller includes an array of one or more amplifiers, and the array of one or more amplifiers includes two amplifiers for each of the one or more receive channels.

[0058] The techniques described herein and their attributes and attendant advantages will be best appreciated and understood from the following detailed description when read in conjunction with the accompanying drawings wherein representative embodiments are described by way of example.

[0059] Incorporated by Reference

[0060] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 A block diagram of a system for performing functions and classifying users of the system according to the inventive concept is illustrated.

[0062] Figure 2 FIG. 1 is a perspective view of an ultrasonic sensor combining an ultrasonic transducer array with a pressure plate according to the present invention.

[0063] Figure 3 According to the present invention, Figure 2 A cross-sectional side view of an ultrasonic sensor.

[0064] Figure 4 It shows that according to the present invention, Figure 2 and Figure 3 A column of electrodes in a platen that emits ultrasonic pulses.

[0065] Figure 5 It shows that according to the present invention, when sensing Figure 4 The ultrasonic pulse from Figure 2 and Figure 3 The top surface of the platen generates echoes when reflected by the row electrodes.

[0066] Figure 6 It is shown that according to the present invention, Figures 2 to 5 Waveforms recorded from the row electrodes during emission and sensing of one pixel element of the ultrasound sensor.

[0067] Figure 7 FIG. 1 illustrates a time offset between a baseline sub-waveform and a signal sub-waveform in an embodiment according to the inventive concept.

[0068] Figure 8 According to the present invention, using Figures 2 to 5 Block diagram of a finger sensor system that uses an ultrasonic sensor array to image a finger based on time offset.

[0069] Fig. 9 According to the inventive concept, a time-shifted image of a fingerprint is compared with a conventional amplitude-shifted image of the same fingerprint.

[0070] Fig.10 It shows a fingerprint image generated using only the signal arrival time of the signal waveform according to the present inventive concept.

[0071] Fig.11 is a flowchart of an ultrasound signal processing method using baseline time compensation in an embodiment of the inventive concept.

[0072] Fig.12 is a flow chart of a method for processing a waveform to identify an arrival time of an echo in an embodiment according to the inventive concept.

[0073] Fig.13 is a flow chart of a method for processing a waveform to identify an arrival time of an echo in an embodiment according to the inventive concept.

[0074] Fig.14 A method for processing a signal and a baseline waveform to identify a time offset in accordance with the present inventive concept is illustrated.

[0075] Fig.15 A method for processing a waveform to identify the arrival time of an echo according to the present inventive concept is illustrated.

[0076] Fig.16 is a flowchart of an ultrasound signal processing method for generating a time-shifted image without a baseline waveform in an embodiment of the inventive concept.

[0077] Fig.17 FIG. 4 is a flow chart of a method for detecting an object without using a baseline waveform according to the present invention.

[0078] Fig.18 FIG. 4 is a flow chart of a method for object detection using a baseline waveform according to the present invention.

[0079] Fig.19 is a block diagram of an ultrasound signal processing system that can be used to implement the method embodiments of the present invention in an embodiment of the inventive concept.

[0080] Fig. 20 2 is a perspective view of a multi-platen ultrasonic fingerprint sensor having a first platen and a second platen with different round trip propagation times according to the present inventive concept.

[0081] Fig.21 According to the present invention, Fig. 20 Side cross-sectional view of a multi-platen ultrasonic fingerprint sensor.

[0082] Fig. 22 According to the present invention, Fig. 20 and Fig.21The multi-platen ultrasonic fingerprint sensor is electrically driven to simultaneously transmit a first ultrasonic pulse into a first platen and a second ultrasonic pulse into a second platen.

[0083] Fig.23 According to the present invention, Fig. 22 The multi-platen ultrasonic fingerprint sensor senses a first echo and a second echo.

[0084] Fig.24 According to the present invention, Figure 20 to Figure 23 A side cross-sectional view of a multi-platen ultrasonic fingerprint sensor similar to that of FIG. 1 , except that it has a coplanar front end face.

[0085] Fig.25 FIG. 1 is a side cross-sectional view of a multi-platen ultrasonic fingerprint sensor according to the present invention, wherein only one pixel transducer array is used for both the first and second platens.

[0086] Figures 25A-25D Various electrical configurations of ultrasonic sensors according to the present invention are shown.

[0087] Fig.26 FIG. 4 is a block diagram of a fingerprint sensing system using a multi-platen ultrasonic fingerprint sensor according to the present invention.

[0088] Fig. 27 FIG. 1 is a side cross-sectional view of an ultrasonic fingerprint sensor with a wedge-shaped pressure plate according to the present invention.

[0089] Fig.28 Two cross-sectional side views of a multi-platen ultrasonic fingerprint sensor with an anti-reflection coating according to the present inventive concept are shown.

[0090] Figures 29 to 34G Various schematic diagrams, cross-sectional views, perspective views, exploded views, and graphs of simulated signals of a system including user classification according to the present inventive concept are illustrated.

[0091] FIG. 35A to FIG. 45B Various schematic diagrams, cross-sectional views, perspective views, exploded views, flow charts, and graphs of simulated signals of a system including user classification according to the inventive concept are illustrated.

[0092] Fig.46 is a cross-sectional view of a sensor according to the inventive concept, the sensor including two ultrasound film layers and the sensor being attached to a display.

[0093] Figures 47A-47F are cross-sectional views and top views of steps of manufacturing an ultrasonic sensor according to the inventive concept.

[0094] Fig.48A-B is a cross-sectional view of various embodiments of an ultrasound sensor according to the inventive concept, the ultrasound sensor comprising two ultrasound film layers attached to a display.

[0095] Fig.49 is a block diagram of the hardware and software portions of a system according to the inventive concept.

[0096] Fig.50 is a flowchart of a method of performing an imaging process according to the inventive concept.

[0097] Fig.51 A cross-sectional view of a sensor in accordance with the present inventive concept attached to a portion of a housing of a device is shown.

[0098] Fig.51 a shows a top view of a user device including two fingerprint recognition sensors according to the inventive concept.

[0099] Fig.52 A cross-sectional view of a sensor including a backing layer according to the present inventive concept is shown.

[0100] Fig.53 A schematic diagram of a beamforming method implemented using hardware according to the inventive concept is shown.

[0101] Fig.54A and 54B A schematic diagram of a control circuit of an ultrasonic sensor according to the present invention is shown.

[0102] Fig.55A -F shows a series of images depicting translation of the beamforming focal point on a platen in accordance with the present inventive concept.

[0103] Fig.56A -C respectively show examples of a fully filled array, a randomly filled sparse array, and an optimized sparse array of ultrasound elements according to the present inventive concept.

[0104] Fig.57 A diagram representing an ultrasound beam pattern according to the inventive concept is shown.

[0105] Fig.58 A diagram of signals recorded by an ultrasonic sensor according to the inventive concept is shown.

[0106] Fig.59A -B and Fig.60A -B shows a diagram illustrating a beamforming scheme according to the inventive concept.

[0107] Fig.61A and 61B A cross-sectional view of an embodiment of a sensor attached to a metal platen in accordance with the inventive concept is shown.

[0108] Fig.62 A cross-sectional view of a portion of an embodiment of a sensor in accordance with the inventive concepts attached to a metal platen is shown.

[0109] Fig.62A and 62B Graphs showing transmission pressure and reception sensitivity of a sensor according to the inventive concept, respectively.

[0110] Fig.62C A graph showing a frequency shift based on an electrode thickness of a sensor according to the inventive concept is shown.

[0111] Fig.63A and 63B Simulated fingerprint images corresponding to sensors with different operating frequencies according to the inventive concept are shown.

[0112] Fig.64A and Fig.64B Schematic diagrams showing two embodiments of apodization configurations for a row-column addressed sensor array in accordance with the present inventive concept.

[0113] Fig.65 A schematic diagram showing an embodiment of a sensor configuration with redundant receiving circuits according to the inventive concept is shown. DETAILED DESCRIPTION

[0114] Embodiments of the present technology will now be described in detail, examples of which are illustrated in the accompanying drawings. Similar reference numerals may be used to refer to similar components. However, this specification is not intended to limit the disclosure to specific embodiments, but should be interpreted as including various modifications, equivalents and / or substitutions of the embodiments described herein.

[0115] It will be appreciated that certain features of the invention that are described in the context of separate embodiments for the sake of clarity may also be provided in combination in a single embodiment. Conversely, various features of the invention that are described in the context of a single embodiment for the sake of brevity may also be provided separately or in any suitable sub-combination. For example, it will be appreciated that all features recited in any claim (whether independent or dependent) may be combined in any given manner.

[0116] It is to be understood that at least some of the drawings and descriptions of the present invention have been simplified to focus on elements relevant to a clear understanding of the present invention, while other elements that would be apparent to one of ordinary skill in the art and that may also constitute a part of the present invention have been eliminated for the sake of clarity. However, because such elements are well known in the art and because they do not necessarily promote a better understanding of the present invention, a description of such elements is not provided herein.

[0117] The terms defined in the present disclosure are only used to describe the specific embodiments of the present disclosure, and are not intended to limit the scope of the present disclosure. The terms provided in the singular are intended to also include plural forms, unless the context clearly indicates otherwise. All terms including technical or scientific terms used herein have the same meaning as the general understanding of those of ordinary skill in the relevant art, unless otherwise defined herein. The terms defined in the commonly used dictionaries should be interpreted as having the same or similar meaning as the contextual meaning of the relevant technology, and should not be interpreted as having an ideal or exaggerated meaning, unless clearly defined in this article. In some cases, the terms defined in the present disclosure should not be interpreted as excluding embodiments of the present disclosure.

[0118] It is to be understood that the terms “comprising” (and any forms of comprising, such as “comprise” and “comprises”), “having” (and any forms of having, such as “have” and “has”), “including” (and any forms of including, such as “includes” and “include”), and / or “containing” (and any forms of containing, such as “contains” and “contain”), when used herein, specify the presence of recited features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0119] It is also understood that although the terms "first," "second," "third," etc., may be used herein to describe various limitations, elements, components, regions, layers, and / or sections, these limitations, elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are only used to distinguish one limitation, element, component, region, layer, or section from another limitation, element, component, region, layer, or section. Thus, the first limitation, element, component, region, layer, or section discussed below may be referred to as a second limitation, element, component, region, layer, or section without departing from the teachings of the present application.

[0120] It is also understood that when an element is referred to as being "on," "attached," "connected," or "coupled" to another element, it can be directly on or over the other element, or directly connected or coupled to the other element, or there can be one or more intervening elements. In contrast, when an element is referred to as being "directly on," "directly attached," "directly connected," or "directly coupled" to another element, there are no intervening elements. Other words used to describe relationships between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.).

[0121] As used herein, the terms "operably attached," "operably connected," "operably coupled," and similar terms related to component attachment shall refer to the attachment of two or more components resulting in one, two, or more of the following: electrical attachment; fluid attachment; magnetic attachment; mechanical attachment; optical attachment; acoustic attachment; and / or other operable attachment arrangements. The operable attachment of two or more components may facilitate the transmission of the following between the two or more components: power; signals; electrical energy; fluid or other flowable material; magnetism; mechanical connection; light; sound (e.g., ultrasound); and / or other materials and / or components.

[0122] It should also be understood that when a first element is referred to as being "in," "on," and / or "inside" a second element, the first element may be positioned as: within the interior space of the second element, within a portion of the second element (for example, within a wall of the second element); positioned on the outer surface and / or inner surface of the second element; and combinations of two or more of these situations.

[0123] As used herein, the term "adjacent", when used to describe a first component or location being adjacent to a second component or location, should be understood to include one or more locations that are adjacent to the second component or location, as well as locations in, on, and / or within the second component or location. For example, a component positioned adjacent to an anatomical site (e.g., a target tissue location) should include components positioned adjacent to the anatomical site, as well as components positioned in, on, and / or within the anatomical site.

[0124] Spatially relative terms, such as "below," "beneath," "lower," "above," "upper," and the like, may be used to describe the relationship of one element and / or feature to other element(s) and / or feature(s), for example, as shown in the accompanying drawings. It is also to be understood that the spatially relative terms are intended to encompass different orientations of the device in use and / or operation in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, the orientation of elements described as "below" and / or "beneath" other elements or features would then be "above" the other elements or features. The device may be in other orientations (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptions used herein may be interpreted accordingly.

[0125] As used herein, the term "reduce" shall include a reduction in quantity, including reduction to zero. Reducing the likelihood of occurrence shall include preventing occurrence. Accordingly, as used herein, the term "prevent" shall include the action of "reducing".

[0126] As used herein, the term "and / or" should be understood as specifically disclosing each of the two specified features or components, with or without the other. For example, "A and / or B" should be understood as specifically disclosing each of (i) A, (ii) B, and (iii) A and B, just as if each were individually listed herein.

[0127] As used herein, the term "one or more" may mean one, two, three, four, five, six, seven, eight, nine, ten or more, up to any number.

[0128] The terms "and combinations thereof" and "and combinations of these" may each be used herein after a list of items to be included individually or collectively. For example, a component, process, and / or other item selected from the group consisting of A, B, C, and combinations thereof should include one or more component sets including: one, two, three, or more item A; one, two, three, or more item B; and / or one, two, three, or more item C.

[0129] In this specification, unless explicitly stated otherwise, "and" may mean "or", and "or" may mean "and". For example, if a feature is described as having A, B, or C, the feature may have A, B, and C, or any combination of A, B, and C. Similarly, if a feature is described as having A, B, and C, the feature may have only one or both of A, B, or C.

[0130] The expression "configured (or set) to" used in the present disclosure may be used interchangeably with, for example, the expressions "suitable for", "capable of", "designed to", "suitable for", "enabled to", and "able to" depending on the situation. The expression "configured (or set) to" does not only mean "specifically designed to" in hardware. Alternatively, in some cases, the expression "a device configured to" may mean that the device "can" operate together with another device or component.

[0131] As used herein, the term "threshold" refers to a maximum level, a minimum level, and / or a range of values ​​associated with a desired or undesired state. In some embodiments, a system parameter is maintained above a minimum threshold, below a maximum threshold, within a threshold range of values, and / or outside a threshold range of values, such as to cause a desired effect (e.g., to successfully perform a function as expected) and / or to prevent or otherwise reduce (hereinafter referred to as "prevent") an undesired event (e.g., to perform a function by an undesired or impaired user). In some embodiments, a system parameter is maintained above a first threshold and below a second threshold. In some embodiments, a threshold is determined to include a safety margin, such as to take into account user variability, system variability, tolerances, and the like. As used herein, "exceeding a threshold" involves a parameter being above a maximum threshold, below a minimum threshold, within a threshold range, and / or outside a threshold range.

[0132] As used herein, "chamber pressure" shall refer to the pressure of the environment surrounding the systems and devices contemplated by the present invention. "Positive pressure" includes pressures that are higher than the chamber pressure or pressures that are greater than another pressure, such as a positive pressure differential across a fluid path component (such as a valve). "Negative pressure" includes pressures that are lower than the chamber pressure or pressures that are less than another pressure, such as a negative pressure differential across a fluid path component (such as a valve). Negative pressure may include a vacuum, but does not mean a pressure that is lower than a vacuum. As used herein, the term "vacuum" may be used to refer to a complete or partial vacuum, or any negative pressure as described above.

[0133] The term "diameter" used herein to describe a non-circular geometric body should be understood to be the diameter of an imaginary circle that approximates the geometric body being described. For example, when describing a cross-section (e.g., a cross-section of a component), the term "diameter" should be understood to mean the diameter of an imaginary circle having the same cross-sectional area as the cross-section of the component being described.

[0134] As used herein, the terms "major axis" and "minor axis" of a component are the length and diameter, respectively, of a hypothetical cylinder of the smallest volume that can completely surround the component.

[0135] As used herein, the term "fluid" may refer to a liquid, a gas, a gel, or any flowable material, such as a material that can be propelled through a lumen and / or an opening.

[0136] As used herein, the term "material" may refer to a single material, or a combination of two, three, four or more materials.

[0137] As used herein, the term "transducer" should be understood to include any component or combination of components that receives energy or any input and produces an output. In some configurations, the transducer converts an electrical signal into any output, such as: light (e.g., a transducer including a light emitting diode or a light bulb), sound (e.g., a transducer including one or more piezoelectric transducers and / or a capacitive micromachinedultrasound transducer (CMUT) configured to transmit and / or receive ultrasonic energy); pressure (e.g., applied pressure or force); thermal energy; cryogenic energy; chemical energy; mechanical energy (e.g., a transducer including a motor or solenoid); magnetic energy; and / or a different electrical signal (e.g., different from the input signal of the transducer). Alternatively or additionally, the transducer may convert a physical quantity (e.g., a change in a physical quantity) into an electrical signal. Alternatively or additionally, the transducer may include a mechanism, such as: a valve; a gripping element; an anchoring mechanism; an electrically activated mechanism; a mechanically activated mechanism; and / or a thermally activated mechanism.

[0138] As used herein, the term "functional element" should be understood to include one or more elements constructed and arranged to perform a certain function. The functional element may include one or more sensors and / or one or more transducers. The functional element (e.g., including one or more sensors) may be configured to record one or more parameters. In some embodiments, the functional component is configured to perform a function. A "functional assembly" may include an assembly constructed and arranged to perform a certain function. Alternatively or additionally, a functional assembly may be configured to record one or more parameters, such as user parameters; user environment parameters; and / or system parameters. A functional assembly may include one or more functional elements.

[0139] As used herein, the term "system parameter" includes one or more parameters of the system of the present inventive concepts.

[0140] As used herein, the term "user parameters" or "operator parameters" includes one or more parameters associated with a user (also referred to as an "operator") of the system contemplated by the present invention. The user parameters may include user physiological parameters, such as physiological parameters selected from the group consisting of: temperature (e.g., tissue temperature); pressure, such as blood pressure or other body fluid pressure; pH; blood gas parameters; blood glucose levels; hormone levels; heart rate; respiratory rate; and combinations of these. Alternatively or additionally, the user parameters may include user environmental parameters, such as environmental parameters selected from the group consisting of: user geographic location; temperature; pressure; humidity level; light level; time of day; and combinations of these.

[0141] As used herein, the term "transmitting a signal" and its derivatives shall refer to the transfer of power and / or data in any direction between two or more components.

[0142] As used herein, the term "conduit" may refer to an elongated member including one or more flexible and / or non-flexible filaments selected from the group consisting of: one, two or more wires or other electrical conductors (e.g., including an outer insulator); one, two or more waveguides; one, two or more hollow tubes, such as hydraulic tubes, pneumatic tubes and / or other fluid transport tubes; one or more optical fibers; one, two or more control cables and / or other mechanical linkages; one, two or more flexible circuits; and combinations thereof. A conduit may include a tube including a plurality of conduits positioned within the tube. A conduit may be configured to operably connect one component to another component electrically, fluidically, acoustically, optically, mechanically and / or otherwise.

[0143] As used herein, an "ultrasonic transducer" (also referred to as an "ultrasonic element") may refer to one or more components configured to transmit ultrasonic energy (e.g., based on a transmitted electrical signal) and / or one or more components configured to receive ultrasonic energy (e.g., and convert it into an electrical signal). An ultrasonic transducer may include a group of one or more ultrasonic transducers, such as a 1D or 2D array of ultrasonic transducers. An ultrasonic transducer may refer to: a group of one or more piezoelectric transducers (also referred to as "piezoelectric" transducers or elements); a group of one or more capacitive micromachined ultrasonic transducers (CMUTs), or a group of one or more of the two.

[0144] As used herein, an “optical transducer” (also referred to as an “optical element”) may refer to one or more components configured to transmit light (e.g., diodes such as laser diodes) and / or one or more components configured to receive light and / or facilitate the propagation of light (e.g., lenses, prisms, optical fibers, etc.).

[0145] The systems, devices and methods of the present invention include one, two or more sensors (e.g., ultrasound-based sensors, capacitive sensors and / or light-based sensors) configured to collect data about a user. The collected data (e.g., fingerprint data, pulse oximetry data and / or other physiological and anatomical data) can be used to verify whether an appropriate user is present to use the device or system.

[0146] Reference now Figure 1, in accordance with the present inventive concept, a schematic diagram of a system for performing functions for a user is illustrated. The system 10 may be configured to perform functions, such as performing one or more functions associated with a smartphone or other cellular telephone (“smartphone” or “cellular telephone” herein), a watch such as a smartwatch, a gaming device, a computer (e.g., a tablet device or laptop computer), a vehicle, equipment, a storage device (e.g., a secure storage device), and / or other user-accessible devices or systems. The system 10 may be configured to perform an identification routine (e.g., to determine the identity of one or more users), and / or a confirmation routine (e.g., to confirm the identity of one or more users). The system 10 may be configured to perform a classification routine, such as classifying one or more users of the system 10, such as classification including identifying a user (e.g., determining and / or confirming the identity of a user), and / or characterizing a health or other condition of a user (e.g., confirming and / or identifying a health or other condition of a user). The user identification and / or confirmation routine (either or both referred to herein as "identification routine" or "confirmation routine") can be performed in various ways, such as via a fingerprint, via an image of the user's face, via a recording of a person's voice, via recorded vital signs of the user (e.g., current physiological parameters), and / or via a combination of two or more of these items. In some embodiments, two, three or more forms of data (e.g., fingerprint, facial image, voice recording, and / or physiological data) are used to determine the identity of the user and / or provide other status information of the user (e.g., current health status). In some embodiments, the user's physiological data (e.g., such as the following physiological data: pulse oximetry data; blood glucose data; EEG, LFP, neuronal firing patterns and / or other brain data; heart rate data; breathing data; sweat data; and / or blood gas data) can be characterized (e.g., pattern recognition) in a classification routine to, for example, identify, confirm, and / or otherwise characterize the user's health status. Alternatively or additionally, physiological data collected by system 10 may also be used to identify and / or authenticate (herein "identify" or "authenticate") a user, in an arrangement similar to that performed using fingerprints, facial images, and / or voice recordings.

[0147] System 10 includes one, two or more sensors, such as sensor 100 shown in the figure. Sensor 100 may include one or more sensors that are positioned adjacent to another component of system 10 (e.g., within and / or on it). Sensor 100 may include an ultrasound-based sensor, such as a piezoelectric-based, CMUT-based, and / or other ultrasound-based sensors such as those described herein. In some embodiments, sensor 100 includes one, two or more sensors selected from the group including: an ultrasound-based sensor; a capacitive touch sensor; an optical sensor; an electrical sensor; a magnetic sensor; a force sensor; a pressure sensor; a strain gauge; an accelerometer, a physiological sensor; a microphone (e.g., for recording a user's voice); a camera (e.g., for recording a user's face); and combinations thereof. The sensor 100 may include a "detection area" that includes one or more 2D or 3D surfaces from which user input can be recorded, such as user input including the following: contact by a user's finger or other body part (e.g., to select an icon, type on a keyboard, and / or otherwise enter data into a user interface); an image of the user's tissue, such as a fingerprint or other tissue surface; the temperature of the user's tissue; the user's pulse oximetry, blood pressure, electrocardiogram, and / or other physiological information; and combinations thereof. In some embodiments, the sensor 100 includes an ultrasound-based sensor, such as that described herein. Figures 2 to 65 Described in .

[0148] The system 10 may include one, two or more cellular phones (such as smart phones), watches (such as smart watches), gaming devices, tablet computers, computers, user protection devices, vehicles or other transportation devices, banking and / or other transaction devices, medical devices and / or other user devices, as shown in the figure as user device 500. In some embodiments, the sensor 100 is integrated with the user device 500. Each user device 500 may include a user interface, as shown in the figure as user interface 550. The user interface 550 may include one or more user input components and / or user output components, such as one or more components selected from the group including the following: display; touch screen display; light, such as LED; switch; button; knob; key area, such as membrane key area; keyboard; control stick; joystick; speaker; microphone; vibration sensor and / or other tactile sensor; capacitive sensor or switch; ultrasonic-based sensor or switch; and combinations of these. Each user device 500 may include a communicator, as shown in the figure as communicator 570, which may be configured to transmit information between the user device 500 and another component of the system 10, such as transmitting information between components. The communicator 570 may include a wired communication assembly, such as when the communicator 570 includes a cable, the cable is configured to operably (e.g., electrically) attach the user device 500 to another component of the system 10. Alternatively or additionally, the communicator 570 may include a wireless communication module, such as an NFC and / or Bluetooth module configured to transmit information between the user device 500 and another component of the system 10. Each user device 500 may include one or more assemblies, such as a functional assembly 580 as shown, which may be configured to provide output and / or otherwise perform functions of the user device 500. The functional assembly 580 may include one or more components that provide functions selected from the group including: cellular phone functions, such as communication functions and / or smart phone functions; transportation functions; storage functions; gaming functions; medical device functions (e.g., treatment and / or diagnostic functions); testing functions, such as laboratory testing functions; manipulation functions (e.g., mining functions); entertainment functions; storage functions, such as secure storage functions; data processing functions; computer functions; financial transaction functions; and combinations thereof.

[0149] In some embodiments, the user interface 550 includes the sensor 100, for example when the user interface 550 includes a multi-layer construction, and all or at least a portion of the sensor 100 is integrated into one or more layers of the interface 550, for example, with reference to FIG. 35A to FIG. 40B In these embodiments, the user interface 550 may include a touch screen, and the integrated sensor 100 may include an ultrasound-based sensor (e.g., see, for example, Figures 2 to 28In some embodiments, the user interface 550 includes such an ultrasound-based sensor, but the interface 550 lacks one or both of a capacitive-based sensor and / or an optical sensor (e.g., the ultrasound-based sensor 100 is configured to provide all touch-based user input to the user interface 550 and associated device 500). Alternatively, the user interface 550 may include a sensor 100 that includes an ultrasound-based sensor and one or both of a capacitive sensor and an optical sensor.

[0150] The user interface 550 may include an integrated sensor 100 that may be constructed and arranged to receive user input from a majority of the “surface” of the user interface 550 (e.g., a user-accessible surface portion of the interface 550), such as when the detection area of ​​the sensor 100 (e.g., an ultrasound-based sensor as described herein) is at least 51%, at least 70%, at least 80%, and / or at least 90% of the visible portion of the user interface 550. In some embodiments, the detection area of ​​the sensor 100 (e.g., an ultrasound-based sensor as described herein) has a width of at least 10,000 mm. 2 、40,000mm 2 and / or 1,000,000mm 2 area and / or a major axis of at least 20 cm, 40 cm and / or 80 cm.

[0151] In some embodiments, sensor 100 can be positioned near and toward an external portion of device 500, such as a housing portion (e.g., housing 510 described herein), so that sensor 100 can image a fingerprint of a finger placed on the external portion of device 500 near sensor 100. For example, sensor 100 can be positioned along an edge of device 500, and / or near a button or other user control portion of the housing of device 500, such as reference 100. Fig.51 and 51A In some embodiments, a sensor 100 including multiple similar and / or different sensors 100 can be located at one or more locations along one or more edges of the device 500, such as for recording fingerprints of multiple fingers of a user (e.g., capturing multiple fingerprints simultaneously and / or sequentially), as described herein.

[0152] As described herein, the user interface 550 and / or the sensor 100 (e.g., the sensor 100 as described herein as being integral to the interface 550) may include a first sensor configured to operate at a first power level and a second sensor configured to operate at a second power level greater than the first power level. In these embodiments, the system 10 (e.g., the controller 200 described herein) may be configured to operate in a lower power mode in which power is provided to the first sensor but power is not provided to the second sensor (e.g., the second sensor is off or in a standby state). User contact and / or other activation of the first sensor may cause the system 10 to provide power to the second sensor (e.g., turn on or otherwise cause the second sensor to be in an active state). The second sensor may include an ultrasound-based sensor including a plurality of pixel elements as described herein, such as a sufficient number of pixel elements to identify one or more users via one or more fingerprints of the users. The first sensor may include a mechanical switch, a pressure sensor, a capacitive sensor, a low-resolution ultrasound-based pixel transducer array, and / or other low-power sensors. In some embodiments, the first sensor and the second sensor include sensors 100a and 100b, respectively, which are integrated into a user interface 550 of a device 500 (e.g., a cellular phone, tablet device, or other battery-operated device). Similar to sensor 100a, the second sensor 100b can be constructed and arranged to receive user input from a majority of the "surface" of the user interface 550 (e.g., the user-accessible surface portion of the interface 550), such as when the detection area of ​​sensor 100b (e.g., an ultrasound-based sensor as described herein) occupies at least 51%, at least 70%, at least 80%, and / or at least 90% of the visible portion of the user interface 550. In some embodiments, the detection area of ​​sensor 100b (e.g., an ultrasound-based sensor as described herein) has a width of at least 10,000 mm. 2 、40,000mm 2 and / or 1,000,000mm 2 area and / or having a major axis of at least 20 cm, 40 cm and / or 80 cm.

[0153] The system 10 may include one or more control modules, such as a controller 200, which may be configured to send signals to and / or receive signals from the sensor 100. Alternatively or additionally, the controller 200 may be configured to dock or otherwise operably connect two or more components of the system 10 to each other. The controller 200 may include one or more electronic components, electronic assemblies, and / or other electronic components, such as components selected from the group including: memory storage components; analog-to-digital converters; rectifier circuits; state machines; microprocessors; microcontrollers; filters and other signal conditioners; sensor interface circuits; transducer interface circuits; and combinations of these. In some embodiments, the controller 200 includes a memory storage component that includes instructions, such as instructions used by the controller 200 to execute an algorithm (e.g., algorithm 60 described herein). In some embodiments, the controller 200 is integrated with a user device 500 (e.g., a user device 500 including the sensor 100). The controller 200 may be configured to electrically, mechanically, acoustically, fluidically, optically and / or otherwise operably connect two components of the system 10 to each other, such as operably connecting the sensor 100 to another component of the system 10, such as to a user device 500 as described herein. The controller 200 may include various electronic components and circuits configured to operably interface with one or more components of the system 10, and / or facilitate any component of the system 10 to operably interface with another component of the system 10. In some embodiments, the controller 200 includes one or more application specific integrated circuits (ASICs), such as one, two or more ASICs, which are configured to transmit signals to and / or receive signals from one or more pixel elements of the ultrasound-based sensor 100 as described herein. In some embodiments, as described herein, a single ASIC is configured to drive at least 250 transmit lines and at least 250 receive lines. In other embodiments, multiple ASICs are configured to drive (e.g., arranged in parallel) at least 500 pairs, at least 1000 pairs, and / or at least 5000 pairs of transmit lines and receive lines.

[0154] System 10 may include FOB 600 as shown. FOB 600 may include one, two or more portable terminals (fobs) and / or other handheld electronic devices or other devices (referred to herein as "portable terminals"), such as devices configured to fit into a user's pocket, purse, wallet, and / or other user locations, so that the user can easily carry FOB 600 in daily life activities. In some embodiments, FOB 600 includes sensor 100 (e.g., also controller 200). For example, FOB 600 may include at least one ultrasonic-based sensor, such as described herein, for example, to identify a user's fingerprint. FOB 600 may include user interface 650 as shown. In some embodiments, the construction and arrangement of user interface 650 is similar to user interface 550 described herein. The FOB 600 may include an assembly, such as a communicator 670, which may be configured to transmit information between the FOB 600 and another component of the system 10, such as between the FOB 600 and the user device 500 (e.g., when the FOB 600 includes the sensor 100 and the user information recorded by the sensor 100 is transmitted to the user device 500 via the communicator 670). The communicator 670 may include a wired communication assembly, such as when the communicator 670 includes a cable, the cable is configured to operably (e.g., electrically) attach the FOB 600 to the device 500 and / or another component of the system 10. Alternatively or additionally, the communicator 670 may include a wireless communication module, such as an NFC and / or Bluetooth module, which is configured to transmit information between the FOB 600 and the communicator 570 of the user device 500 and / or a similar wireless module of another system 10 component.

[0155] System 10 may include one, two, or more accessory devices, such as accessory device 700. Accessory device 700 may include one or more devices that operate in conjunction with another component of system 10. In some embodiments, accessory device 700 includes all or a portion of sensor 100 and / or all or a portion of controller 200.

[0156] System 10 may include one or more algorithms, such as algorithm 60. Algorithm 60 may include machine learning, neural network, and / or other artificial intelligence algorithms (referred to herein as "AI algorithms").

[0157] Algorithm 60 may include an algorithm configured to detect fraudulent attempts at a user confirmation routine performed by system 10 .

[0158] Algorithm 60 may include an algorithm configured to analyze a user's vital signs (e.g., pulse oximetry, blood glucose, heart rate, blood pressure, respiration, EKG, EEG, LFP, and / or neuronal discharges) to identify and / or characterize the user, for example, via analysis (e.g., analysis of a single physiological parameter or a combined analysis of multiple physiological parameters).

[0159] Algorithm 60 may include an algorithm that analyzes fingerprint data (e.g., recorded by sensor 100) to identify a user. In some embodiments, algorithm 60 includes an algorithm that analyzes fingerprint data and another form of user data to identify a user, such as other data including: facial images (e.g., images produced by a camera of system 10); voice recordings (e.g., recordings produced by a microphone of system 10); physiological data (also referred to herein as vital sign data); and combinations of these. In these embodiments, algorithm 60 may include weighting factors and / or biases that prioritize one type of user identification data over another type of user identification data.

[0160] The system 10 may include one, two or more computer networks, such as network 800, such as cellular and / or other wireless networks, LANs, WANs, VPNs, the Internet, and / or other computer networks. In some embodiments, user information and / or other information collected and / or generated by components of the system 10 is transmitted to one or more central locations via network 800, such as when the information includes information related to the use of the system 10 by multiple users (e.g., multiple users of various components of the system 10), the system 10 analyzes the information, such as by the algorithm 60 of the system 10 as described herein. This analysis of information from multiple users of the system 10 can be used to improve the performance of the system 10 for one or more users of the system 10. In some embodiments, the algorithm 60 includes an AI algorithm that analyzes the information collected from multiple users via network 800.

[0161] System 10 may include one, two or more functional elements, such as functional element 199 of sensor 100, functional element 599 of user device 500, functional element 699 of FOB 600, and / or functional element 999, each of which is shown. Each functional element 199, 599, 699 and / or 999 may include one, two or more functional elements, such as one or more sensors and / or one or more transducers, such as described herein.

[0162] The sensor 100 may include one, two, or more sensors 100. The sensor 100 may include a plurality of similar sensors and / or a plurality of dissimilar sensors (e.g., two or more different fingerprint sensors). The sensor 100 may include one or more sensors 100 that are integrated with another component of the system 10 (e.g., integrated with the user device 500) (e.g., positioned on and / or within the other component and operably attached to the other component), and one or more sensors 100 that are integrated with a different component of the system 10 (e.g., integrated with the FOB 600, the accessory device 700, and / or a different user device 500).

[0163] As described herein, the sensor 100 may include at least an ultrasound-based sensor, such as a sensor including an array 150 that includes one, two, or more ultrasound transducers (e.g., piezoelectric and / or CMUT elements) configured to transmit, receive, or both transmit and receive ultrasound energy. In some embodiments, the controller 200 is configured to drive the array 150 (e.g., a 1D or 2D array of ultrasound transducers) at a frequency of at least 1 MHz, 5 MHz, 10 MHz, 25 MHz, or 50 MHz, such as when the controller 200 drives the array 150 at a frequency between 50 MHz and 500 MHz or between 12.5 MHz and 100 MHz. In some embodiments, the controller 200 is configured to drive the ultrasound-based array 150 at a frequency of no more than 500 MHz or no more than 750 MHz. In some embodiments, the sensor 100 includes a glass piezoelectric arrangement, and the controller 200 is configured to drive the array 150 at a frequency of at least 50 MHz and / or no more than 500 MHz. Alternatively or in addition, the sensor 100 may include a plastic piezoelectric (e.g., PVC) arrangement, and the controller 200 may be configured to drive the array 150 at a frequency of at least 12.5 MHz and / or no more than 100 MHz. In some embodiments, the controller 200 is configured to drive the array 150 at a frequency below 50 MHz (e.g., below 40 MHz) and / or at least 10 MHz. The sensor 100 may be configured as a phase and / or delay measurement arrangement (e.g., and operate without frequency limitations). In some embodiments, the sensor 100 is configured to perform transmit and receive beamforming for ultrasonic transmissions.

[0164] In some embodiments, the sensor 100 is configured to operate when operating in wet and / or "underwater" (e.g., immersed in a fluid) conditions, and has significant repeatability, specificity, or both. The system 10 and sensor 100 can be configured to operate in a variety of wet conditions. In some embodiments, the sensor 100 is configured to have improved performance during wet or other conditions, for example, when the sensor 100 includes an enhanced fingerprint detector that sends ultrasonic signals deeper into the finger when the finger and / or the surface contacted by the finger is wet (e.g., when the system 10 is configured to perform high-value bank transaction confirmation and / or other high-security scans). For operation in wet conditions, high-importance confirmation modes, and / or other conditions, the sensor 100 may include a mass-loaded ultrasonic transducer, such as a Langevin transducer. The sensor 100 can drive the center frequency of the ultrasonic transmission at a lower level, such as a level low enough to propagate through (e.g., through) patient tissue.

[0165] In some embodiments, the sensor 100 includes an ultrasound array (e.g., a piezoelectric ultrasound array) that includes an arrangement of row electrodes and column electrodes as described herein. The row electrodes and column electrodes may include two sets of conductors (or "wires" or "traces") that are relatively orthogonal to each other, such as described in U.S. Patent No. 9,953,205. Alternatively, the two sets of conductors may be arranged at an angle less than 90°, such as an angle not greater than 89°, an angle between 1° and 89°, and / or an angle of at least 45°. In some embodiments, the row electrodes and column electrodes have a uniform width along their length. Alternatively or additionally, one or more of these electrodes of the sensor 100 may include a non-uniform width, for example, when the conductor narrows between the locations of the ultrasound transducer (e.g., allowing more light to propagate through the narrowing of the conductor arrangement that forms the set of row electrodes and column electrodes). In these non-uniform arrangements, the thickness of the conductor may be increased to obtain a similar resistance as in a uniform arrangement (e.g., the increase in conductor thickness may be associated with a change in the backing of the piezoelectric transducer and / or the drive frequency of the transducer).

[0166] In some embodiments, the sensor 100 includes an ultrasound array (e.g., a piezoelectric ultrasound array) that can provide a minimum resolution of a user's fingerprint (and / or other tissue surface of a user, such as a palm or other tissue surface), such as a resolution of at least 100 pixels per inch, at least 200 pixels per inch (PPI), at least 350 PPI, at least 500 PPI, and / or at least 1000 PPI. In some embodiments, the system 10 is configured to provide a resolution of at least 200 μm of a fingerprint or other image captured by the sensor 100, such as a resolution of at least 200 μm, 75 μm, 50 μm, 25 μm, and / or 10 μm. In some embodiments, the system 10 is configured to capture a minimum number of pixels of a fingerprint or other image captured by the sensor 100, such as at least 15,000 pixels, at least 25,000 pixels, at least 35,000 pixels, at least 50,000 pixels, and / or at least 100,000 pixels.

[0167] In some embodiments, sensor 100 is configured as a touch sensor (eg, for detecting a tap or other touch by a user). In these embodiments, sensor 100 may also be configured as a fingerprint sensor or other sensor for identifying a particular user.

[0168] In some embodiments, sensor 100 includes an ultrasound-based sensor 100a and a light-based sensor 100b positioned behind sensor 100a such that light transmitted and / or received by sensor 100b passes through sensor 100a, such as described in U.S. Pat. No. 10,691,912.

[0169] In some embodiments, sensor 100 includes at least a light sensor configured to assess vitality of a user and / or assess another physiological parameter of a user.

[0170] In some embodiments, the sensor 100 is configured to provide feedback to the user of the system 10, such as thermal feedback and / or mechanical feedback as described herein. For example, the sensor 100 may include an ultrasound-based sensor configured to provide thermal (e.g., heating) and / or mechanical (e.g., force or other tactile) feedback to the user. In these embodiments, the user device 500 including both the user interface 550 (e.g., a touch screen or other display screen) and the sensor 100 may be configured to operate in a "dark mode" in which communication with the user may be provided via thermal, mechanical, and / or other tactile feedback without the user viewing the user interface 550 (e.g., providing a "keep dark" capability, such as in military or law enforcement operations, and / or when the device 500 is in a user's pocket or other personal hidden storage location). In some embodiments, the form and / or level of feedback may change based on the remaining amount of "battery life" (e.g., the energy remaining in the battery and / or other energy sources of the system 10 (e.g., the energy source of the user device 500)), such as when the change in the form and / or level of feedback is determined by the algorithm 60.

[0171] As described above, the sensor 100 may be configured to provide feedback, instructions, and / or other information (referred to herein as "feedback") to a user of the system 10. For example, the feedback provided to the user may include vibrations, thermal sensations, audio signals (e.g., beeps), and / or other non-textual and / or non-verbal feedback that indicates to the user (e.g., via training) that the user is to take an action (e.g., apply a different finger to the user interface 550, move a currently contacted finger to a new location, and / or perform another physical activity). The feedback provided may include at least a thermal sensation, such as when the sensor 100 causes an increase in the temperature of a patient's finger or other tissue of the patient. For example, the sensor 100 may include a pressure plate (e.g., a glass pressure plate), as described herein, and the controller 200 may be configured to provide a drive signal to the array 150 of the sensor 100 that matches the resonant frequency of the pressure plate, thereby transmitting power to the user's tissue (e.g., a finger) in contact with the sensor 100, causing a thermal tactile sensation. In some embodiments, the controller 200 provides sufficient power to cause an increase in tissue temperature associated with "hot touch" feedback, such as an increase in tissue temperature of at least 0.2°C, such as at least 0.5°C, at least 1.0°C, at least 5.0°C, and / or at least 10.0°C. In some embodiments, the controller 200 is configured to cause the tissue temperature to increase by no more than 4°C, no more than 10°C, no more than 20°C, and / or no more than 30°C. In these embodiments, the pressure plate may include a uniform thickness so that the pressure plate creates a resonant acoustic cavity. When the frequency of the drive signal provided by the controller 200 matches the resonance of the cavity, multiple reflections within the pressure plate can be added in a constructive manner and transmitted to the finger at the same time. In these embodiments, the drive signal provided by the controller 200 may include a continuous wave / tone burst signal (e.g., non-pulse excitation). The above-mentioned resonance-based feedback can be configured to provide a mechanical sensation to the user (e.g., as an alternative or supplement to thermal feedback, such as by modulating the drive signal, such as a frequency of 300Hz). In some embodiments, the controller 200 is configured to provide a chirp signal that causes the ultrasound-based array 150 to transmit ultrasound waves at different frequencies (e.g., as a way to adjust the frequency to match the resonant frequency of the platen). In some embodiments, the mechanical, thermal, and / or other feedback provided by the sensor 100 to the user is adjustable and / or calibrable.

[0172] In some embodiments, system 10 is configured in a "no-look mode" to provide feedback and / or any information (e.g., text provided in Braille) without requiring the user to see or the user to visually notice user interface 550, user interface 650, and / or other display portions of system 10 (e.g., when the user is blind or user device 500 is in a pocket, purse, or other non-line-of-sight location relative to the user). In these embodiments, system 10 may be configured to provide thermal, mechanical, and / or other tactile feedback to the user, representing various forms of information.

[0173] In some embodiments, the system 10 is configured in an "enhanced feedback mode" to, for example, provide tactile feedback (e.g., thermal or mechanical feedback as described herein) as well as visual feedback. This enhanced feedback mode can be used to improve the user experience of gaming and / or other applications of the user device 500. In some embodiments, the device 500 is capable of receiving (e.g., downloading) third-party applications, and the sensor 100 is configured to provide tactile feedback used by these applications. In some embodiments, the system 10 includes a calibration function that is configured to adjust the feedback provided to the third-party application.

[0174] In some embodiments, the sensor 100 includes a plurality of sensors 100 (e.g., a plurality of similar sensors 100) arranged in a close proximity arrangement (e.g., the periphery of each sensor 100 abuts the periphery of an adjacent sensor), wherein the plurality of sensors 100 can be collectively configured (e.g., in an interface arrangement) to function as a single sensor 100 (e.g., by electronic "stitching" via the controller 200). For example, the sensor 100 may include: 3 sensors in a 1 by 3 array; 4 sensors in a 1 by 4 array, or 4 sensors in a 2 by 2 array; 6 sensors in a 1 by 6 array, or 6 sensors in a 2 by 3 array; etc. The plurality of sensors of the sensor 100 can be constructed and arranged (e.g., attached to a flexible or hinged substrate) to rotate relative to each other (e.g., at least two sensors rotate relative to each other), such as when included in a device configured to flex (e.g., a smart card or other device where flexibility or at least flexing provides advantages). Each of the multiple sensors of the sensor 100 may include an array of one, two or more ultrasonic transducers (e.g., multiple piezoelectric and / or CMUT sensors), such that the multiple ultrasonic transducer arrays can be rotated relative to each other, but can also be operated as a single transducer array (e.g., multiple arrays collectively provide a larger effective sensing area than any individual array, but can also be rotated relative to adjacent arrays to provide greater flexibility than a single area of ​​similar area). In some embodiments, the sensor 100 and / or another component of the system 10 is configured to monitor and / or otherwise determine the relative position between the multiple sensors 100 (e.g., multiple individual and / or multiple groups of two or more pixel transducers and / or other piezoelectric sensors as described herein). The relative position of the sensors 100 can be used for one or more purposes, such as performing beamforming between sensors, stitching together images (e.g., fingerprint images or other tissue images), and other functions associated with the relative position of the multiple sensors 100. In some embodiments, the transmission and / or reception of ultrasonic energy (e.g., by multiple sensors of the sensor 100) is used to determine the position of these sensors and / or other sensors of the sensor 100.

[0175] In some embodiments, the user device 500 includes all or a portion of the sensor 100 , and / or all or a portion of the controller 200 .

[0176] In some embodiments, user device 500 includes one, two, or more devices that provide access to user device 500 and / or user operations of user device 500 after system 10 performs a confirmation routine (also referred to as an "identification routine"). The confirmation routine may include one, two, or more confirmation routines selected from the group consisting of: identifying the user, such as via one or more fingerprints of the user (e.g., as described herein); recognizing the user's face; confirming an acceptable "health condition" of the user (e.g., the user is alive, and / or the user is in a safe physical and / or mental state); confirming that the user is not significantly affected by alcohol and / or drugs (e.g., the user is not intoxicated according to applicable standards); and combinations of these.

[0177] User equipment 500 may include a cellular telephone, such as a smartphone.

[0178] User device 500 may include a device worn by a user, such as a smart watch or other watch device.

[0179] User device 500 may include a computer device, such as a laptop or tablet device.

[0180] User device 500 may include a user protection device, such as a gun or a Taser.

[0181] User equipment 500 may include a transportation device, such as a car, a motorcycle, a bus, a boat (eg, a yacht), an airplane, a helicopter, and / or other means of transportation.

[0182] User device 500 may include equipment (eg, construction equipment) such as a bulldozer, a crane, and / or excavation equipment. User device 500 may be a piece of laboratory equipment.

[0183] User device 500 may include a "card device" such as a credit card, personal ID card, passport, and / or driver's license.

[0184] User device 500 may include a memory storage device, such as a USB drive.

[0185] User device 500 may include a crypto wallet device.

[0186] User device 500 may include a user device selected from the group consisting of: a door lock; a medicine cabinet lock; a storage device, such as a gun storage container and / or storage facility; a child lock; and combinations of these.

[0187] The user device 500 may include a medical device. For example, the user device 500 may include a medical device configured to provide treatment, such as when the system 10 is configured to confirm the identity of a healthcare professional (e.g., via data provided by the sensor 100), once confirmed, the professional sets and / or modifies the treatment provided by the medical device. The user device 500 may include a medical device that allows entry of medical information, such as when the system 10 is configured to confirm the identity of a healthcare professional (e.g., via data provided by the sensor 100), once confirmed, the professional may enter and / or modify medical information. In some embodiments, the system 10 may be configured to be used by multiple healthcare workers (e.g., doctors, nurses, and / or other healthcare workers configured as users of the device 500), wherein different users have different levels of permissions, wherein the different levels of permissions are associated with different levels of permissions to change or access a patient's medical information and / or change settings of the user device 500 (e.g., change treatment parameters of the user device 500 including the medical device).

[0188] User device 500 may include two, three or more devices selected from the group consisting of: phones, such as smartphones or other cellular phones (referred to herein as "smartphones" or "cellular phones"); computer devices; user protection devices; transportation devices; equipment; card-based devices; memory storage devices; crypto wallet devices; medical devices; other user devices (e.g., as described herein), and combinations of these.

[0189] As described herein, system 10 may include FOB 600. In some embodiments, user device 500 includes FOB 600. In some embodiments, FOB 600 includes all or part of sensor 100, and / or all or part of controller 200. FOB 600 may be configured to send information to user device 500, such as via wired and / or wireless connection. In some embodiments, FOB 600 includes at least a portion of sensor 100 (e.g., and at least a portion of controller 200) and is configured to identify one or more fingerprints of the user and / or otherwise perform a confirmation routine to the user, as described herein. In these embodiments, once the user can be confirmed by FOB 600 (e.g., it is an acceptable user and / or the user is in an acceptable health condition), the confirmation can be sent to user device 500 (e.g., otherwise the user device that is not configured to perform fingerprint scanning and / or other user confirmation). In some embodiments, FOB 600 includes a sensor 100 that includes an ultrasound-based fingerprint sensor 100a and a light-based sensor 100b (e.g., a light-based sensor configured as a pulse oximeter (e.g., a reflective oximeter)), such as when sensor 100a transmits light emitted by sensor 100b (e.g., when sensor 100b is positioned behind sensor 100a).

[0190] FOB 600 may include sensor 100, for example, when sensor 100 includes at least an ultrasound-based sensor as described herein. Alternatively or additionally, FOB 600 may include sensor 100, sensor 100 including a physiological sensor (e.g., a pulse oximeter or other light-based physiological sensor). For example, FOB 600 may include sensor 100, sensor 100 including a first sensor 100a including an ultrasound-based sensor (e.g., a fingerprint sensor) and a second sensor 100b including a light-based sensor whose light is transmitted through sensor 100a (e.g., when sensor 100a is configured to let light pass, such as described in U.S. Pat. No. 10,691,912).

[0191] FOB 600 may be configured to recognize a user's fingerprint, and / or perform another user identification as described herein, and transmit confirmation of the user to user device 500 (eg, when user device 500 does not include a fingerprint sensor or other sensor to identify the user).

[0192] In some embodiments, system 10 is configured to identify a user using two, three, or more identification routines (e.g., as described herein) selected from a group including: ultrasound-based fingerprint recognition; capacitive sensor-based fingerprint recognition; vital sign recognition (e.g., using a pulse oximeter or other light-based physiological sensor); vital sign identification; and combinations of these routines, such as described herein.

[0193] In some embodiments, the system 10 is configured to perform a calibration routine, such as a calibration routine configured to calibrate a sensor 100 including a single sensor and / or a sensor 100 including multiple sensors (e.g., multiple similar and / or dissimilar sensors). In some embodiments, the system 10 is configured to perform a calibration routine after a portion of the system 10 is damaged (e.g., a portion of the sensor 100 and / or a portion of a user device 500 adjacent to the sensor 100 is damaged) or otherwise malfunctioning, such as to allow use of the system 10 after performing the calibration. For example, the sensor 100 may include an array of elements (e.g., ultrasonic elements), and after detecting that some elements are damaged, a calibration routine may be performed in which an undamaged portion of the sensor 100 is used, the damaged portion is no longer used, and the identification routine of the inventive concept may be successfully performed using the undamaged portion of the sensor 100. In another example, the user device 500 may include a cellular phone having a cracked portion of the screen of the user interface 550 of the cellular phone through which the sensor 100 sends and / or receives transmissions, and a calibration routine may be performed to accommodate the cracked screen and allow the user identification routine to be successfully completed. In some embodiments, the device 500 may be modified after the initial calibration routine and then perform (e.g., must perform) a second calibration routine. For example, the user device 500 may include a cellular phone to which a protective case, screen protector, or other covering has been added, and the system 10 may be configured to perform a calibration routine (e.g., a second calibration routine) to compensate for the added covering. In some embodiments, the algorithm 60 includes an AI or other algorithm that is configured to determine (e.g., in a confirmation routine) which subset of elements in the array of elements (e.g., pixel elements) of the sensor 100 to use (e.g., for imaging a fingerprint or other object), for example to compensate for damage to the housing 510 and / or other portions of the sensor 100, to adjust for a covering that has been added to the device 500, and / or to otherwise select a subset of elements of the sensor 100 to use.

[0194] System 10 can be configured to authenticate a user or a group of multiple users in a financial transaction (e.g., a bank transfer). In some embodiments, multiple devices 500 (e.g., multiple cell phones), each including sensor 100, are used to authenticate a single user and / or multiple users.

[0195] In some embodiments, the system 10 is configured to perform the confirmation routine multiple times during use of the device 500, for example, to confirm that the user has not changed, and / or that the user's health has not changed. For example, the system 10 can require successful completion of the confirmation routine on a repetitive basis (e.g., on a periodic and / or random basis), such as when the user device 500 includes a car, an aircraft, and / or equipment, and requires repeated confirmation to prevent one or more of the following situations: user switching; use by a single user for a long time; and / or use by a user whose health condition becomes unacceptable.

[0196] In some embodiments, the system 10 includes a first component C1 (e.g., FOB 600) and a second component C2 (e.g., device 500), the former including a first sensor 100a and the latter including a second sensor 100b. The sensor 100a can be configured to collect two different forms of data from the user, such as data classified as "confidential data" (e.g., fingerprint data, facial recognition data, voice recording data and / or other data that the user may wish to keep confidential), i.e., data CD herein, and data classified as "non-confidential data" (e.g., facial recognition data, voice recording data, physiological data, such as current physiological data), i.e., data NCD herein. The sensor 100b can be configured to collect at least non-confidential data NCD. During the authentication procedure, C1 can collect both confidential data and non-confidential data from the user, namely, CD 1 and NCD 1 , and C2 can collect non-confidential data from users (e.g., similar non-confidential data), NCD 2 . Data NCD 1 and NCD 2 Can be collected simultaneously (e.g., the user interfaces with C1 and C2 simultaneously or at least within a short period of time (e.g., within a few minutes). Data NCD 2 Can be sent from C2 to C1. C1 can collect confidential information based on CD 1 First confirm the user to execute the user confirmation routine. Once the confirmation is successfully completed, C1 can 1 and NCD 2 Compare to confirm the non-confidential data NCD collected by C2 2from the same user. If the comparison indicates that the same user is docked with each device, data representing confirmation of the user may be sent from C1 to C2. In these embodiments, confirmation of the user may be provided to a device (e.g., C2 as described above) without requiring C2 to receive confidential information of the user (i.e., the user may use their fingerprint, facial image, voice data, and / or other data that the user wishes to keep confidential in the user confirmation routine without sharing the confidential data with devices separate from FOB 600). In some embodiments, C2 may be configured to perform a confirmation routine including receiving an NCD from C1. 1 (For example, confirm CD in C1 1 After being associated with the correct user), C2 will receive the NCD 1 NCD collected with C2 2 In some embodiments, C1 includes FOB 600 and C2 includes user equipment 500 (e.g., a cell phone, computer, ATM or other financial transaction device, etc.). In some embodiments, NCD 1 and NCD 2 Includes user input data (e.g., data not recorded by the associated sensor 100). For example, NCD 1 May include an alphanumeric or other code that is presented to the user (e.g., via C1) and entered by the user into C2 as an NCD 2 , such as when configured as a two-factor authentication routine. In some embodiments, data CD and / or data NCD are collected from multiple users of system 10, such as when a first user confirms the identity of a second user, or when confirmation from multiple users is required to perform an event (e.g., a financial transaction). In some embodiments, component C1 described above (e.g., FOB 600) is configured for a single use (e.g., a single confirmation to a user), and FOB 600 can be destroyed or otherwise disposed of after its use. In some embodiments, FOB 600 is configured for use by (e.g., and provided by) a user to a recognized institution (e.g., a notary public, a government agency, or the like). For example, the institution may identify a user via one or more means (e.g., a driver's license, passport, fingerprint, facial recognition, and / or voice recognition) and then configure FOB 600 to be assigned to the user (e.g., via collecting and storing in FOB 600 data representing the user's fingerprint, face, voice, or other data that may be collected by the integrated sensor 100) to, for example, perform future confirmation routines for that user (e.g., providing a confirmatory electronic digital signature, such as provided by a service provider such as DocuSign, providing an alternative to notarization, etc.).

[0197] In some embodiments, the confirmation routine performed by system 10 may be configured to confirm multiple fingerprints from a user (e.g., pre-assigned by the user and / or system 10), such as at least one fingerprint from each hand of the user. During the confirmation routine, multiple fingerprints are collected (e.g., collected by sensor 100) and confirmed (e.g., confirmed by algorithm 60). In some embodiments, correct confirmation also requires a specific fingerprint collection order (e.g., an order pre-assigned by the user and / or system 10). In some embodiments, system 10 (e.g., via user interface 550 and / or 650) provides feedback to the user as to which fingerprint to collect next (e.g., via a graphical image of the user's left and / or right hand).

[0198] In some embodiments, the user device 500 includes a housing (e.g., housing 510 described herein), such as a metal or plastic housing surrounding at least a portion of each of the user interface 550, the communicator 570, the functional assembly 580, and / or the functional element 599. For example, the user device 500 may include a smart phone that includes a user interface 550 and a housing surrounding the back and sides of the phone, the user interface 550 including a touch screen that defines the front of the phone. In some embodiments, as described herein, the sensor 100 can be integrated into the user interface 550 so that the sound generated and received by the sensor 100 passes through at least a portion of the user interface 550. Alternatively or additionally, the sensor 100 can be integrated into the housing 510 of the user device 500 so that the sound generated and received by the sensor 100 passes through at least a portion of the housing 510 (e.g., when the user places a finger on a portion of the housing 510), as described herein.

[0199] In some embodiments, the accessory device 700 includes a device configured to be positioned on or otherwise adjacent to the user device 500 (e.g., around at least a portion thereof), such as when the device 700 includes a protective device (e.g., a screen protector and / or a phone case). The sensor 100 (e.g., at least a portion of the sensor 100) can be integrated into the accessory device 700. In some embodiments, the sensor 100 (e.g., a sensor 100 positioned within the cover-based accessory device 700 and / or a sensor 100 positioned within the user device 500) is configured to receive power from the user device 500, such as wirelessly transmitted power provided via inductive coupling. Alternatively or additionally, the sensor 100 can also receive power from a wired connection of the user device 500, such as when the sensor 100 (e.g., a sensor 100 integrated into the accessory device 700) is connected to the user device 500 via a USB connection. In some embodiments, the sensor 100 is configured to communicate with the user device 500, such as via wired or wireless communication (e.g., via NFC, Bluetooth, or other short-range wireless communication methods).

[0200] In some embodiments, the user interface 550 includes an integrated ultrasound-based sensor 100, such as a sensor 100 that includes an array of orthogonal and / or other XY-arranged conductors (also referred to herein as "wires," "wires," and / or "electrodes"). The sensor 100 can be constructed and arranged to have a relatively thin profile, such as a sensor 100 having a thickness of less than or equal to 40 μm and / or 20 μm. The user interface 550 may include an "exposed surface area" (e.g., a surface area that is viewable, touchable, and / or otherwise accessible to a user) that is at least 25 mm in area. 2 , for example at least 10,000 mm 2 and / or at least 40,000mm 2 In some embodiments, the sensor 100 is configured to record a swipe motion of a user's finger, and the user interface 550 incorporating the sensor 100 may include at least 5 mm 2 and / or 10mm 2area. The ultrasound-based sensor 100 can be integrated into the user interface 550, for example when the sensor 100 is adhered to or directly deposited (e.g., without the use of an adhesive) onto a display screen (e.g., an OLED, microLED, LCD, and / or other display screen) of the user interface 550. The ultrasound-based sensor 100 may include a detection area that is at least 50% of the exposed surface area of ​​the interface 550 (e.g., at least 50% of the viewable portion of the integrated OLED or other display screen). In some embodiments, the ultrasound-based sensor 100 may have a detection area that is at least 75%, 85%, and / or 95% of the exposed surface area of ​​the interface 550. In some embodiments, the detection area of ​​the ultrasound-based sensor 100 has a detection area of ​​at least 10,000 mm 2 、40,000mm 2 and / or 1,000,000mm 2 The ultrasonic sensor 100 may be configured to detect contact by a user (e.g., contact via one or more fingers of the user), record fingerprints and / or other physiological information of the user, or both. The ultrasonic sensor 100 may include an XY arrangement of conductors (e.g., as described herein) positioned at different densities (e.g., different separation distances between the conductors). For example, at least a portion of the detection area may have a density sufficient to identify a fingerprint of the user, while at least another portion may have a lower density, such as a density sufficient to detect contact by the user. In some embodiments, the ultrasonic sensor 100 is relatively transparent, or includes one or more relatively transparent portions, so that light passes through the sensor 100, for example, to allow a user to visualize a display screen positioned below the sensor 100 and / or to allow diagnostic light (e.g., for pulse oximetry) to pass through the sensor 100. As described herein, a user interface 550 including an integrated sensor 100 may include a multi-layer (e.g., laminated) construction. In these embodiments, the thickness of one or more layers can be based on the acoustic wavelength of ultrasound transmitted and / or received by sensor 100 of user interface 550. For example, user interface 550 can include an adhesive layer having a thickness configured to maximize transmission of ultrasound through the layer.

[0201] Sensor 100 may include an ultrasound-based sensor that includes one or more parts (e.g., layers) that are deposited (e.g., sputtered, spun, printed, baked, thin-film deposited, vapor deposited, photolithographically deposited, and / or otherwise directly deposited) onto a layer of one or more materials selected from the group consisting of: a pressboard or other substrate layer (e.g., a glass or plastic pressboard as described herein); a surface of a display screen (e.g., an OLED or other display screen); a previously deposited layer of sensor 100; any material layer (e.g., a substrate layer of user interface 550); and combinations of these. In these embodiments, sensor 100 can be relatively fixed to another component (e.g., a layer of interface 550 as described herein) without requiring any adhesive.

[0202] In some embodiments, the user interface 550 includes a first ultrasound-based sensor 100a and a second ultrasound-based sensor 100b. In these embodiments, the first sensor 100a and the second sensor 100b can be positioned on opposite sides of a display screen (e.g., an OLED or other display screen) of the interface 550, such as with reference to FIG. Figures 38A-38B The first sensor 100a can be relatively transparent (e.g., including at least one relatively transparent portion) so that the first sensor 100a can be positioned above the display screen (e.g., without obstructing the user from viewing the display screen). In these embodiments, the user interface 550 can be integrated into the device 500 (e.g., a cellular phone, a tablet device, and / or other handheld electronic device) and can capture user input (e.g., commands and / or images, such as fingerprints) via user contact (e.g., finger contact) on either or both sides of the device.

[0203] In some embodiments, the user interface 550 includes two display screens positioned on either side of the ultrasound-based sensor 100, such as described herein with reference to FIG. Figures 38A-38B described.

[0204] In some embodiments, device 500 (e.g., including user interface 550 with integrated ultrasound-based sensor 100) includes a controller for a gaming device (e.g., a gaming table or other gaming device including a user interface portion having a detection area including a major axis or major diameter of at least 20 inches, 30 inches, and / or 40 inches). For example, user interface 550 may include a sufficiently large detection area and be configured to allow use by multiple users, such as multiple users sitting in chairs and / or standing in an arrangement that allows comfortable space between users. In some embodiments, user interface 550 is configured to distinguish touches between different users (e.g., via fingerprint recognition), as described herein.

[0205] In some embodiments, sensor 100 is flexible, such as when sensor 100 includes wires (eg, transmit and / or receive wires) deposited directly on a layer of piezoelectric material.

[0206] In some embodiments, sensor 100 includes a set of conductors (eg, transmit and / or receive conductors) where at least a portion of the set of conductors are positioned at different densities (eg, different separation distances between pairs of conductors).

[0207] The system 10 can be constructed and arranged to simultaneously or sequentially identify, characterize and / or distinguish contacts of multiple fingers, such as at least 2, 3, 4, 5, 6 and / or 11 fingers, via the sensor 100. In some embodiments, the multiple fingers are fingers of multiple users, such as at least 2, 3, 4, 5, 6 and / or 11 fingers common to multiple users. In some embodiments, the sensor 100 includes a first sensor 100a positioned on a first user interface 550a and a second sensor 100b positioned on a second user interface 550b, and the system 10 (e.g., a system used by multiple users to play video games or other multi-user programs) is configured to detect one or more fingerprints of each of the one or more users via each sensor 100. Alternatively or additionally, the system 10 can be configured to identify (e.g., via the algorithm 60) one or more fingerprints of multiple users via a single sensor 100 (e.g., a single sensor 100 integrated into a single display screen of the user interface 550, such as a single display screen accessed by the fingers of multiple users). For example, device 500 or another system 10 component may be configured to detect multiple fingerprints to distinguish one user from another user (e.g., to control an application based on the specific user providing input), and / or to distinguish one finger from another finger of a single user (e.g., to control an application based on which specific finger of the specific user is providing input). In some embodiments, sensor 100 includes at least one high-density sensing area and at least one low-density sensing area, such as when the high-density sensing area includes closer sets of X and Y conductors than the low-density sensing area. In these embodiments, the high-density sensing area may include one, two, or more areas that are configured to detect fingerprints from two or more users. In these embodiments, performing a task may require multi-user confirmation, such as to initiate a medical procedure, a weapon attack, a large financial transaction, and / or other events that require initiation consensus from multiple users. In some embodiments, device 500 comprises a vehicle (e.g., an airplane) and / or equipment where multiple users control device 500, such as when device 500 performs confirmation of the identities of two users via sensor 100 (e.g., fingerprint detection detected by one, two or more sensors 100 and / or other confirmation as described herein). In these embodiments, after user identification, certain functions of the device may be available to one user (e.g., one of two pilots, or one of two equipment operators) but not to the other user, and / or vice versa. In some embodiments, device 500 comprises a large user interface device that can be located in a public place (e.g., an airport or a town square) and accessed by multiple users (e.g., at least 3, 5, or 10) simultaneously.For example, device 500 may include a user interface 550 having a large aspect ratio (e.g., a large width to height ratio) to be used, for example, by multiple users simultaneously to: request delivery, order food, make reservations, etc. In such a configuration, system 10 may be configured to distinguish one user from another based on fingerprint data obtained via sensor 100, for example, if the user changes their location while accessing device 500.

[0208] In some embodiments, the sensor 100 includes an ultrasound-based sensor 100 that is configured to capture (e.g., image) a portion, such as a majority of a user's hand (e.g., a majority of a palm), and a specific user can be identified through the captured hand data.

[0209] In some embodiments, the sensor 100 includes an ultrasound-based sensor 100 that includes an X and Y conductor set as described herein. The thickness, width, and / or length of these conductors may be based on the layer (e.g., platen) in which the conductors are located. In some embodiments, the piezoelectric layer includes polyvinylidene fluoride (e.g., applied as a large sheet or spun similar to a photoresist process), and the sensor 100 may operate in a frequency range of 25 MHz to 50 MHz. In some embodiments, the piezoelectric layer includes a layer having a thickness between 9 μm and 10 μm. For a resolution of 1 mm, the conductors can be positioned at a period of 1 mm (e.g., 0.5 mm conductor width with a spacing of 0.5 mm). For sensors 100 with higher resolution, the period may be increased accordingly. The lengths of the X and Y conductors can be based on the specific use (e.g., application) of the sensor 100, for example to accommodate large display screens (e.g., display screens having a major axis or diameter of at least 20 inches, 30 inches, and / or 40 inches) for gaming devices (e.g., gaming tables) and / or public display applications, or relatively smaller display screens suitable for cellular phones. Longer conductors tend to have increased thicknesses, for example to reduce the overall resistance of the conductors. The thickness of the conductors can be at least 0.1 μm, for example at least 0.2 μm, 0.5 μm, 1.0 μm, and / or 2.0 μm. In some embodiments, the conductor thickness is selected based on the power requirements of the system.

[0210] In some embodiments, the system 10 is configured to capture the user's fingerprint at an accelerated rate. The system 10 can identify the user's fingerprint by two steps: a fingerprint "data acquisition" step and a fingerprint "data processing" step. The data acquisition step includes: acquiring the user's fingerprint information and converting the analog data generated by the sensor 100 (e.g., an ultrasound-based sensor as described herein) into digital data that can be processed by the controller 200 (e.g., processed by an algorithm 60 including an AI algorithm and / or other algorithms). Subsequently, a data processing step can be performed in which the controller 200 processes the data from the sensor 100, such as processing that occurs in several steps, to determine whether a specific user is confirmed via the fingerprint data.

[0211] The duration of the data acquisition step depends on the number of transmission and reception events (TR-RX events) performed by the sensor 100, which depends on the number of X and Y conductors used for transmission and reception (e.g., all conductors present and / or a subset of these conductors), and the number of parallel readouts (e.g., signal acquisition of all X or Y conductors). Data acquisition time T DA It can be determined by the following formula:

[0212] T DA = (number of TX-RX events) x (duration of a single TX-RX event) x (average number of times)

[0213] In some embodiments, the sensor 100 includes 250 transmit conductors (e.g., 250 X conductors) and 250 receive conductors (e.g., 250 Y conductors), where in each TR-RX event, a single conductor is used for transmission and a single conductor is used for reception. In this configuration, the total number of TR-RX events is equal to: 250 times 250 divided by 2, which is 31,250 times.

[0214] The duration of a single TX-RX event is the minimum waiting time required between consecutive TX-RX events. This waiting time is based on the time required for the ultrasonic echo reverberating inside the sensor 100 platen to die out (to avoid echo overlap before consecutive TX-RX events), and is determined by parameters including the acoustic velocity, thickness, and associated attenuation of the sensor 100 platen material. In some embodiments, the sensor 100 includes a ZnO sensor, and the waiting time may be approximately 1 μs.

[0215] "Averaging" is a term used to define the process of taking a set of repeated measurements from the same TX-RX location and then averaging all of these measurements. Averaging reduces noise and improves the signal-to-noise ratio by filtering out uncorrelated noise that is typically present in electronic systems. More averaging produces higher signal-to-noise ratio (SNR) values, and the system 10 can be configured to perform a minimum number of averages (e.g., 16 or more). In some embodiments, the system 10 does not perform averaging.

[0216] In some embodiments, the sensor 100 includes 250 transmit conductors and 250 receive conductors, as described above, and the current total data acquisition time is equal to 31.25 ms without averaging and equal to 500 ms with averaging. In some embodiments, the system 10 includes additional (e.g., more than two) parallel readout circuits (e.g., including more electronic circuits and their associated power consumption and product volume). For example, the system 10 may include 16 readout circuits, and the associated data acquisition time will be shortened to 3.9 ms and 62.5 ms (without and with averaging, respectively). In some embodiments, the sensor 100 is configured to shorten the data acquisition time.

[0217] In some embodiments, the sensor 100 may include an ultrasound-based sensor that includes a piezoelectric deposited on a platen (e.g., a glass platen), and conductors (e.g., metal wires) above and below the piezoelectric layer. The piezoelectric (e.g., zinc oxide ZnO) may be deposited directly on a display screen (e.g., an OLED or other display screen) of the user interface 550. The sensor 100 may have a relatively thin construction, such as when including a thickness of no more than 40 μm, 30 μm, and / or 20 μm. As described herein, the sensor 100 may be integrated into the user interface 550 without the need for adhesive bonding (e.g., no epoxy layer and / or other adhesive is required to attach the sensor 100 to the display screen or other layer components of the interface 550). The sensor 100 and the user interface 550 may be manufactured in a single process. In some embodiments, the sensor 100 and the user interface 550 are tested (e.g., manufacturing quality testing) as a single assembly (e.g., a user interface 550 including an integrated sensor 100). In some embodiments, sensor 100 includes an ultrasound-based sensor that includes X and Y conductors as described herein, and at least one set of conductors is deposited onto a substrate (e.g., glass) portion of a display screen (e.g., OLED or other display screen) of user interface 550 prior to manufacturing the entire display screen (i.e., one or more portions of the display screen are assembled to the display screen after the X and / or Y conductors are deposited). The conductors may be deposited onto a portion of the display screen, housing, and / or another component of device 500 or system 10, for example, via sputtering, photolithography, and / or other deposition processes (e.g., as described herein). The manufacture of the integrated sensor (e.g., interface 550 or housing 510 with integrated sensor 100) may be performed in an assembly line (e.g., one by one) manufacturing process, and / or in a batch mode (e.g., a mode of manufacturing multiple at a time, e.g., at least 10, such as when conductors of at least 10 sensors 100 are deposited simultaneously (e.g., onto at least 10 displays of 10 user interfaces 550 or otherwise).

[0218] In some embodiments, sensor 100 comprises a "flexible sensor," e.g., a sensor that includes one or more flexible portions or is relatively flexible as a whole. Sensor 100 may include an ultrasound-based flexible sensor that includes a flexible layer of polyvinylidene fluoride (PVDF). In these embodiments, device 500 may include a "flexible device," e.g., a device that includes one or more flexible portions that support a certain level of bending, such as a credit card configured to support slight bending (e.g., when located in a wallet) without damage. Sensor 100 may include a flexible sensor that is attached to (e.g., directly deposited onto or adhered to) a display (e.g., an OLED or other display), such as a display of user interface 550.

[0219] In some embodiments, the sensor 100 includes an ultrasound-based sensor, as described herein, which includes X and Y conductors, and the sensor 100 is also configured as a capacitive touch sensor (e.g., detecting a user's contact based on a measured change in capacitance). In these embodiments, the sensor 100 may be configured to switch between a low-power capacitive touch sensing mode and a higher-power ultrasonic transmission and reception mode (e.g., a mode in which at least two groups of at least 128 conductors or at least 256 conductors actively transmit and receive ultrasonic waves). In these embodiments, the sensor 100 may include a detection area that occupies a majority (e.g., at least 50%, 75%, 85%, and / or 95%) of the exposed surface area of ​​the user interface 550 in which the sensor 100 is integrated. In some embodiments, the detection area of ​​the sensor 100 (e.g., an ultrasound-based sensor as described herein) has a width of at least 10,000 mm. 2 、40,000mm 2 and / or 1,000,000mm 2 area, and / or a major axis of at least 20 cm, 40 cm and / or 80 cm.

[0220] In some embodiments, the sensor 100 includes an ultrasound-based sensor (e.g., including X and Y conductors as described herein) configured to be integrated into a user interface 550 that includes a relatively thick glass layer through which ultrasound waves are sent and received. The relatively thick glass layer can be configured to reduce breakage and / or avoid the need for a screen protector (e.g., a screen protector that is typically attached to a cell phone screen for protection). The user interface 550 (e.g., a device 500 in which the user interface 550 and the sensor 100 are integrated) can be configured to operate in harsh environments, such as when used in military applications, outdoor use, and / or water activities.

[0221] The user interface 550 including the ultrasound-based sensor 100 may be configured to detect touches by one or more fingers of a user when the fingers are covered by fabric or other flexible material (e.g., gloves or finger sleeves). In these embodiments, the user may apply one or more fingers to the imageable surface of the sensor 100 (e.g., after removing a covering of the one or more fingers) so that the identity of the user can be confirmed (e.g., via one or more fingerprints and / or other physiological confirmation information of the user). After confirmation, the user's fingers may be covered (e.g., restored), and the sensor 100 may receive various forms of user input (e.g., icon selection, etc.) while the one or more fingers being used are still covered.

[0222] The user interface 550 including the ultrasound-based sensor 100 may be integrated into a device 500 including an automated teller machine (ATM) or other banking equipment.

[0223] As described herein, the user interface 550 including the ultrasound-based sensor 100 can be flexible (e.g., including one or more flexible portions), such as when the device 500 including the user interface 550 includes a wearable device including a flexible "smart screen". The device 500 may include a wearable computer device and / or clothing including the user interface 550. The device 500 may include a first portion (e.g., a watch or clothing) including the sensor 100, and a second portion (e.g., a cellular phone, a laptop, a tablet device, and / or other electronic user device) that receives information from the first portion (e.g., via wireless communication). In some embodiments, the first portion is configured to perform a user confirmation routine to, for example, allow one or more functions (e.g., "smart functions") provided by the first portion to be enabled only after access by a permitted (e.g., "authorized") user is confirmed (e.g., via fingerprint detection performed by the first portion and / or the second portion).

[0224] The user device 500 may include a medical device, as described herein. In some embodiments, a user interface 550 including an integrated sensor 100 (e.g., an ultrasound-based sensor 100) is configured to confirm the identity of a nurse, doctor, and / or other authorized caregiver (e.g., via fingerprint recognition) before allowing any parameters of the medical device to be set and / or changed (e.g., turning on, turning off, and / or modifying any settings of the device 500). Alternatively or additionally, the device 500 may be configured to detect and / or measure (referred to herein as "detecting" or "measuring") a user's vital signs and / or other physiological parameters (e.g., including fingerprints) via the sensor 100 to, for example, confirm proper use and / or adjust the treatment provided by the device 500 based on the physiological parameter measurements.

[0225] In some embodiments, the user interface 550 includes an alphanumeric keypad and / or other keyboard. In these embodiments, the ultrasound-based sensor 100 integrated into the user interface 550 can detect one or more fingerprints of one, two, or more users, for example, while the associated one or more users are typing (e.g., entering data via typing) in the same user interface 550. In some embodiments, the system 10 (e.g., via the algorithm 60) is configured to repeatedly confirm the identity of the user during data entry (e.g., to avoid a second non-permitted user continuing to enter data after a permitted user initiates data entry). The repeated confirmation can be repeated continuously based on the time interface (e.g., at least every 10, 20, or 30 seconds) and / or based on the amount of data entered (e.g., repeated after no more than 20, 40, or 60 characters are entered). Alternatively or additionally, system 10 may be configured to confirm the identity of a user via the capture of a fingerprint (e.g., one or more fingerprints), and as long as the finger remains in contact (e.g., continued contact with a pressure level above a threshold) with the portion of system 10 used to capture fingerprints (e.g., user interface 550), a particular user may be considered to be providing input to system 10 (e.g., device 500). However, if the finger "loses contact", system 10 may be configured to require a repeat of the user confirmation routine (e.g., recording and identifying the user again via their fingerprint or other method) to allow the user to continue to control device 500 (e.g., continued control is also dependent on the user's continued contact with the associated device).

[0226] In some embodiments, the sensor 100 includes an assembly including two sensors 100 arranged in a stacked manner: a first ultrasound-based sensor 100a and a second ultrasound-based sensor 100b. In these embodiments, the first sensor 100a may be configured to detect a first set of one or more forms of user input, and the second sensor 100b may be configured to detect a second set of one or more forms of user input. In these embodiments, the first set of one or more forms of user input may include at least one form of user input that is not included in the second set of one or more forms of user input, and / or vice versa. For example, the first sensor 100a may be configured to detect fingerprints of one or more users, while the second sensor 100b may not have a resolution to perform appropriate fingerprint detection. The first sensor 100a may be configured to transition from a dormant state to a wake-up state based on detection of user contact by the second sensor 100b. The controller 200 may include a single electronic module for interfacing with both sensors 100a and 100b (e.g., for sending and / or receiving signals), or it may include different separate electronic modules for each.

[0227] In some embodiments, at least a portion of the detection area of ​​the sensor 100 is positioned along an edge of the user device 500 (e.g., along an edge of the user interface 550 or an edge of the housing 510 of the device 500). For example, a first portion of the sensor 100 (e.g., a set of X and Y conductors, a magnetic switch, and / or other touch-based sensor) positioned along an edge of the device 500 may be configured to cause a second portion of the sensor 100 (e.g., a high-density portion) to transition from a dormant state to an activated state when contacted (e.g., activated) by a user. In some embodiments, the first portion of the sensor 100 is configured to measure a force applied by a user (e.g., one or more fingers of the user, such as when a tap and / or squeezing force is applied to one or more edges of the device 500), such as when a transition of state occurs only when the applied force exceeds a threshold. In some embodiments, the first portion determines the level of applied force by measuring the amount of contact of the user's skin with the first portion, as described herein.

[0228] In some embodiments, sensor 100 comprises an ultrasound-based sensor including an X and Y conductor set as described herein. In these embodiments, sensor 100 may include P V A portion including one or more portions (eg, all) of the sensor 100, wherein each P V The sections include sets of X and Y conductors positioned in a high-density layout such that the sections can operate in low-density, medium-density, and / or high-density operating modes (e.g., providing low, medium, and / or high resolutions based on the number of conductors used for transmission and / or reception, respectively). For example, when P V When the portion is operated in low-density mode, every other, every third, or every "n" conductor (e.g., every n X conductors) is used to transmit ultrasound (e.g., and a corresponding subset of Y conductors is configured to receive reflected ultrasound). Medium-density and high-density modes involve increasing numbers of conductors used for transmission and reception. When P V The portion is operated in a low density mode (eg, a low power mode of the device 500), and a user (eg, a finger of the user) touches an adjacent P V The position of the part (eg, the P contacting the sensor 100) V part of the user interface 550 directly above the part), then at least P V Part (e.g., P V The proximity P of the part and the sensor 100 V In these embodiments, device 500 may generally (e.g., most of the time) operate in a low power mode (e.g., due to P Vlow-density transmit and receive modes), but can transition to a higher power mode where P V Some operate in the medium-density or high-density operating modes described above. V This configuration of the portion allows a user to transition the sensor 100 (e.g., as an integrated part of the user interface 550) from a low power, low density mode to a higher power, medium density, and / or high density mode (e.g., at least one P of the sensor 100) as desired. V Some operate in higher density mode). V Such an arrangement of parts has a number of advantages, such as: saving battery life of device 500, where the high power usage of high density mode is only encountered when needed (e.g., initiated relatively infrequently by a user and / or system 10); and / or faster image (e.g., fingerprint) acquisition time and lower data storage requirements (e.g., compared to scanning only a reduced P V In some embodiments, P V The first "contact" of a part (eg, through one or more layers of user interface 550) causes P V Some of them have changed from low-density operation mode to medium-density operation mode, while P V Part of the second contact will make P V In some embodiments, the user switches to high-density mode in order to have his fingerprint detected (e.g., to have his identity confirmed). In some embodiments, P V The portion automatically transitions to a low-resolution mode after a period of time (e.g., a period of time without user contact and / or without receiving other user input). V The device 500 may transition from low-density mode to medium-density mode and / or high-density mode upon an event selected from the group consisting of: a portion of the housing 510 of the device 500 is touched (e.g., by a user); the user interface 550 is touched (e.g., by a user); a particular time of day is reached; a user physiological parameter reaches a threshold; the device 500 is manipulated in one or more ways (e.g., rotated or shaken), such as when detected by the sensor-based functional element 999; when a particular application (e.g., a game application or other application) is used on the device 500; and combinations of these. In some embodiments, P V The part is operated in high density mode and the user is identified via his fingerprint, after which P V As long as the finger providing the fingerprint remains in contact with the device 500 (eg, the user interface 550), P VIf a loss of contact (eg, contact with sensor 100 via interface 550) is detected, then P V The portion may transition to high density mode (eg, and ask the user to confirm their fingerprint once again).

[0229] In some embodiments, the sensor 100 and / or other components of the system 10 are configured to create an image of biological material (e.g., blood or other biological material), such as biological material that is positioned (e.g., directly positioned and / or positioned on a slide) adjacent to a user interface 550 that includes the integrated sensor 100. In these embodiments, the system 10 may be configured (e.g., via the algorithm 60) to perform analysis on the biological material (e.g., saliva, blood, plasma, and / or cells) to, for example, determine blood type, the presence of pathogens, blood sugar, and / or another detectable parameter of the biological material (e.g., a substance within the biological material). The analysis of the blood and / or other biological material may be performed using time-shifted images, amplitude-shifted images, or both, such as those described herein. In some embodiments, the sensor 100 and / or other components of the system 10 are configured to create an image of an inorganic substance to, for example, perform analysis on the inorganic substance.

[0230] In some embodiments, the controller 200 is configured to provide a drive signal to the sensor 100, and / or receive and process signals recorded by the sensor 100 (e.g., one or more reflections of one or more ultrasonic signals transmitted by the sensor 100 in response to the drive signal provided by the controller 200). The controller 200 can implement various beamforming techniques, such as time domain and / or frequency domain beamforming techniques, which can be used to drive the sensor 100 and / or reconstruct an image from signals received from the sensor 100. For example, the controller 200 can implement time domain beamforming by acquiring and storing a time sequence of echoes ("echoes" herein) of each transmission and reception combination. By using this implementation, the controller 200 can use the entire time sequence to reconstruct an image (e.g., a fingerprint image captured by the sensor 100). Alternatively or additionally, the controller 200 can implement frequency domain beamforming techniques. For example, the controller 200 can perform frequency domain beamforming by oversampling the received signal, for example, by acquiring and storing the echo time series of each transmit and receive combination, and extracting the I / Q components of these signals using software, so that the image can be reconstructed using these I / Q components. Alternatively or additionally, the controller 200 can extract the I / Q components of the signal using an I / Q demodulator (e.g., without oversampling), and use the I / Q values ​​extracted by hardware for image reconstruction. In other embodiments, the controller 200 can perform I / Q sampling using a paired analog-to-digital converter (ADC), for example, as described herein. Fig.49 described.

[0231] In some embodiments, the sensor 100 includes one or more "ultrasound film layers", such that one or more piezoelectric material layers can transmit and / or receive ultrasound waves. Various examples of sensors 100 including a single ultrasound film layer are referred to herein. Figures 35A-39 Examples of sensors 100 including multiple ultrasonic film layers are described herein with reference to Figure 46-48B and other parts are described.

[0232] In some embodiments, the sensor 100 is located below the display of the user interface 550, such as Fig.46 As shown. The system 10 can be configured to reconstruct the fingerprint image of the finger placed on the top side of the display via the ultrasonic signals sent and received by the sensor 100, which pass through the display (e.g., through one or more glass layers or other materials of the display). The controller 200 can be configured to provide a drive signal to the sensor 100 to transmit ultrasonic energy, and process the echoes of these ultrasonic transmissions received from the finger placed on the display, as described herein. The controller 200 can be configured to minimize the effects of overlapping reflections caused by the sensor 100 and / or the layers of the display. In some embodiments, the controller 200 uses a baseline whose adjusted center frequency is configured to produce overlapping echoes with opposite phases. In some embodiments, the system 10 can be configured to acquire image data (e.g., using the air interface of the sensor) without placing an object (e.g., a finger) on the scanner platen, for example to record a baseline. The controller 200 can be configured to use the baseline record to process the image of the object (e.g., a finger), such as extracting a signal of interest from the signal recorded by the controller 200. The controller 200 can be configured to compare the baseline record with the signal recorded during the imaging of the object using subtraction or other image processing techniques to identify the signal of interest. In some embodiments, the controller 200 can use frequency adjustment to enhance the recorded signal, for example, by adjusting the center frequency of the drive signal to eliminate incident reflections caused by various interfaces in the sensor 100 and / or the display. In some embodiments, the controller 200 can use phase demodulation to reconstruct the image, for example, in cases where the tone burst is too long and interferes with the reflection. In these cases, the signal of interest becomes a superposition of the incident signal and the reflected signal, which can be analyzed using phase demodulation.

[0233] In some embodiments, the sensor 100 is configured to perform a first step to prepare the sensor 100 and / or a portion of the user interface 550 for a subsequent second step of imaging, for example, the second step includes an image data acquisition step. Fig.50An embodiment of a two-step imaging process is described.For example, sensor 100 may be configured to pre-process a portion of sensor 100 or another portion of device 500 (eg, a portion of a display or platen) to improve the imaging process.

[0234] In some embodiments, the system 10 is configured to perform time domain beamforming (e.g., as described herein), such as when acquiring and storing a time series of echoes for each transmit-receive (TX-RX) combination. The system 10 can use this time series (e.g., the entire time series) to perform image reconstruction. This configuration provides excellent image quality because the data represents multiple frequencies. This configuration provides flexibility in selecting image reconstruction techniques because the entire time series of interest can be acquired.

[0235] In some embodiments, the system 10 is configured to perform frequency domain beamforming and / or oversampling (e.g., as described herein), such as when acquiring and storing a time series of echoes for each TX-RX combination. The system 10 can extract (e.g., via an algorithm embodied by instructions stored in a memory) I / Q components from the time series and then use the extracted components for image reconstruction. This configuration provides a simple, straightforward method for acquiring I / Q components and provides flexibility in selecting I / Q samples within the acquired time window. This configuration also provides flexibility in selecting image reconstruction techniques (e.g., because the entire time series of interest can be acquired).

[0236] In some embodiments, the system 10 is configured to perform frequency domain beamforming using I / Q demodulation (e.g., as described herein). The system 10 can extract (e.g., in hardware) the I / Q components using an I / Q demodulator (e.g., a dedicated I / Q demodulator), and then sample (e.g., using an analog-to-digital converter (ADC)) and store the I / Q values ​​for each TX / RX combination. The I / Q data is then used for image reconstruction. This configuration reduces data storage requirements (e.g., memory requirements) and data transmission requirements. This configuration also reduces sampling requirements, reduces analog-to-digital converter requirements (e.g., enables the use of lower cost, lower speed ADCs), and reduces power requirements (e.g., enables the use of lower speed ADCs that require less power).

[0237] In some embodiments, the system 10 is configured to perform frequency domain beamforming using I / Q sampling (e.g., as described herein). The system 10 can be configured to extract (e.g., in hardware) the I / Q components using two ADCs with orthogonal phase shifts, for example, combining an I / Q demodulator and an ADC in substantially the same hardware. The stored I / Q data can be used for image reconstruction. This configuration reduces data storage requirements (e.g., memory requirements) and data transmission requirements. This configuration also reduces sampling requirements, reduces analog-to-digital converter requirements (e.g., enabling the use of lower cost, lower speed ADCs), and reduces power requirements (e.g., enabling the use of lower speed ADCs that require less power). This configuration avoids the need for dedicated I / Q demodulation hardware, thereby reducing the associated required power and cost.

[0238] In some embodiments, fingerprints from a set of multiple fingers of a particular user may be respectively assigned to a set of specific instructions executed by the device 500. In these embodiments, the detection of a first fingerprint of a user (e.g., a fingerprint of an index finger or other finger) may be assigned to a first task, the detection of a second fingerprint (e.g., a fingerprint of a middle finger or other non-index finger) may be assigned to a second task, and so on. In this arrangement, a task that may otherwise require multiple steps (e.g., multiple key presses on the user interface 550) may be simplified to a single step of bringing a particular finger close to the sensor 100 (e.g., placing it on a portion of the housing 510 of the device 500 or placing the user interface 550 close to the sensor 100) to perform the task. Applicable tasks may include, but are not limited to: switching from a locked state to an unlocked state; switching from an unlocked state to a locked state; blanking the screen of the user interface 550 or otherwise changing the state; dialing a specific person's phone number; entering an alarm state; dialing 911; entering a specific software program or other function of the device 500; and so on. In some embodiments, different fingerprints are independently associated with a task that unlocks a device with a set of associated different levels of user permissions. For example, a first fingerprint (e.g., a fingerprint of a user's dominant thumb) can fully unlock the device, a second fingerprint (e.g., a fingerprint of a user's index finger) can unlock the device in a partial security mode, such as "child mode", and / or a third fingerprint (e.g., a fingerprint of a user's non-dominant thumb) can unlock the device in a "fake unlock" mode. In some embodiments, the "fake unlock" mode may include an operating mode in which the device 500 appears to be fully unlocked, but sensitive user information remains inaccessible, is further encrypted (e.g., requiring additional user and / or third-party information to decrypt), and / or is automatically deleted when the fake unlock mode is activated. Using different fingerprints to activate different usage modes allows a user to surreptitiously activate various modes, for example, when it is necessary to unlock the device under duress (e.g., when being investigated by an evil organization or evil individual).

[0239] Overall Figures 2 to 19 , illustrates various configurations of sensors 100 and systems 10, such as ultrasound-based systems and sensors utilizing time-shifted images as described herein.

[0240] Many security systems and electronic devices use biometric sensing for user authentication. Compared to other authentication methods (e.g., text-based passwords, cognitive passwords, graphical passwords, passcodes, public key cryptography), biometric authentication uses a person's unique biological, physiological, or behavioral characteristics to verify their identity. These biometric characteristics can be found in a person's fingerprints, facial expressions, irises, language patterns, and other features. Due to their uniqueness, biometric characteristics are generally more difficult to forge than passwords, so biometric authentication can be advantageously combined with other authentication methods to improve overall security.

[0241] Fingerprint-based authentication is a type of biometric authentication that records the ridges and valleys that make up a person's fingerprint. Compared to other types of biometric authentication, fingerprint-based authentication benefits from sensors that are small, rugged, and can be manufactured in large quantities at low cost. As a result, fingerprint-based authentication has become widespread and is used in devices and applications such as mobile devices, automated teller machines (ATMs), and door locks.

[0242] To implement fingerprint-based authentication, an ultrasonic, capacitive, optical, or thermal scanner is typically used to record a digital image of the candidate's fingerprint. Regardless of the scanning technology used, the recorded fingerprint must have a spatial resolution high enough to distinguish between ridges and valleys. For example, the Federal Bureau of Investigation (FBI) and the National Institutes of Standards and Technology (NIST) specify a standard resolution of 500 pixels per inch for automatic fingerprint identification systems (AFIS), corresponding to a pixel imaging size of 50 microns. A pattern matching algorithm can then compare the digital image to a database of fingerprints of "allowed" individuals. If a match is found, the security system infers that the candidate is one of the "allowed" individuals. In this case, the security system can then grant the candidate access.

[0243] Many ultrasound scanners use an array of ultrasonic transducers that can both transmit and sense ultrasound. For example, consider a two-dimensional transducer array that forms rows and columns of pixel elements (referred to herein as "pixel elements" or "pixel transducers"). The transducer array can be attached to the bottom surface of the platen, and each pixel element can be driven to emit an ultrasonic pulse into the platen. A portion of the ultrasonic pulse is reflected from the top surface of the platen and propagates back to the transducer array as an echo. One or more pixel elements sense the echo, and the resulting waveform can be processed to obtain pixels of the corresponding image. When a finger touches the top surface of the platen, the resulting image will reveal the fingerprint of the finger.

[0244] Prior art ultrasonic scanners measure the change in echo energy caused by the ridges contacting the top surface of the pressure plate. For example, consider the valley of a finger in contact with the top surface. In this case, an air pocket is formed between the top surface and the skin, so there is no skin directly contacting the top surface. Because the difference between the mechanical impedance of the pressure plate (usually glass or plastic) and the air is relatively large, the ultrasonic pulse emitted into this area of ​​the pressure plate will be reflected from the top surface with a large reflection coefficient. The resulting valley echo will have relatively high energy. However, where the ridge directly contacts the top surface, the difference between the mechanical impedance of the pressure plate and the skin is smaller. In this area of ​​the pressure plate, the ultrasonic pulse will be reflected from the top surface with a smaller reflection coefficient, resulting in a ridge echo with relatively low energy. Therefore, a fingerprint image can be obtained by mapping the echo energy on the two-dimensional top surface of the pressure plate. Further details on echo energy-based fingerprint imaging can be found in International Publication No. WO 2019 / 032590, entitled “Interactive Biometric Touch Scanner,” and in “A row-column addressed acoustic biometric scanner integrated with pulse oximetry,” by Gerard Touma (Stanford University Ph.D. dissertation, 2020); each of these references is hereby incorporated by reference in its entirety for all purposes.

[0245] The present invention contemplates the use of ultrasound to image fingerprints by recording spatial variations in echo phase or time delay, instead of or in addition to spatial variations in echo energy. Specifically, ridge echoes are phase-shifted relative to valley echoes, so the transducer array will detect a different round-trip pulse propagation time for ridge echoes than for valley echoes. By mapping the echo phase and / or pulse propagation time on the two-dimensional top surface of the platen, a fingerprint image can be obtained.

[0246] Advantageously, the fingerprint images obtained using the inventive concept have a higher signal-to-noise ratio (SNR) than images obtained using prior art energy-based techniques (see Fig. 9 ). As described in more detail below, the higher SNR may be due to the fact that the phase noise of the echo is small relative to its amplitude noise. Therefore, the phase can be measured more accurately than the amplitude. The relatively small phase noise may be due to: the phase noise when the ultrasound pulse is generated is small compared to the amplitude noise; and / or the receiving electronics have smaller electronic phase noise.

[0247] Therefore, the present invention contemplates processing the waveform of the sensed echo using a time-based rather than amplitude-based signal processing technique. For example, each pixel element can be used to record a baseline waveform when no finger is in contact with the pressure plate, and to record a signal waveform when a finger is in contact with the pressure plate. The baseline waveform can be processed to determine the baseline arrival time of the baseline echo, and the signal waveform can be processed to determine the signal arrival time of the signal echo. The baseline arrival time is then subtracted from the signal arrival time (or vice versa) to obtain the time offset of the pixel element. For pixel elements near the valley, the time offset will be relatively closer to zero, while for pixel elements near the ridge, the time offset will be relatively farther away from zero.

[0248] As described in more detail below, there are many ways to process waveforms to determine the echo arrival time, some of which are derived from the field of ultrasonic time domain reflectometry. For example, many ultrasonic transducers are excited using tone bursts (i.e., an integer number of consecutive cycles of a single-frequency sine wave). In this case, the echo will also have the form of a tone burst, and the arrival time can be defined as the time when any node or anti-node in the recorded waveform occurs. Signal processing techniques involving Hilbert transforms or cross-correlations can then be used to determine the time offset. However, other signal processing techniques may also be used without departing from the scope of this article. In addition, the present invention is contemplated to be applicable to any type of pulse excitation and is therefore not limited to tone bursts.

[0249] The inventive concept extends to the operation of a single ultrasonic transducer in contact with the pressure plate. For example, a single ultrasonic sensor can be used to determine the presence of a finger in contact with the top surface of the pressure plate by comparing a measured time offset to a threshold value. An indication of presence can then be output, such as a binary indication (e.g., "0" or "1"), or a value between 0 and 1, indicating the probability of the finger being present. The single ultrasonic transducer can be a pixel element of a transducer array. Alternatively, several pixel elements of the array can be operated to obtain several time offsets, which are then aggregated (e.g., by calculating a mean or variance) to determine the indication. In any case, when the resulting indication indicates the presence of a finger, the transducer array can be controlled to obtain an image of the fingerprint. In this way, the transducer array is used to image the finger only when it is known that there is actually a finger on the pressure plate.

[0250] Although the above discussion describes fingerprint sensing, the present concepts can be used to detect any object in contact with the pressure plate, provided that the presence of the object causes a measurable phase shift in the echo. In addition, although the above discussion describes a two-dimensional transducer array with pixel elements arranged linearly in rows and columns, embodiments of the present invention can be implemented with any type of transducer array, including a one-dimensional pixel arrangement (e.g., a linear or circular arrangement of pixel elements), a two-dimensional pixel arrangement (e.g., a concentric arrangement of pixel elements), and / or a three-dimensional pixel arrangement.

[0251] When used for fingerprint sensing, the inventive concept may be combined with other physical, physiological, and biological measurements, such as when included as part of a multifunctional biometric system. For example, the documents referenced above (i.e., International Publication No. WO 2019 / 032590 and Gerard Touma's doctoral thesis) show how a pulse oximeter can be combined with an ultrasonic transducer array when at least a portion of the transducer array is at least partially optically transparent (e.g., in the near infrared). As another example, the inventive concept can be used to determine the contact area between a finger ridge and a pressure plate. The contact area can be measured over time to identify periodic changes in the indicator pulse. In this way, the biometric system can distinguish between living tissue and inanimate matter. The inventive concept may be combined with other sensors and / or biometric functions without departing from the scope of this document.

[0252] Figure 2 is a perspective view of an ultrasonic sensor 3100 that combines an ultrasonic transducer array 3104 with a pressure plate 3102. Figure 331 is a cross-sectional side view of the ultrasonic sensor 3100. The ultrasonic transducer array 3104 is bonded to or fabricated on the bottom surface 3122 of the platen 3102 such that the ultrasonic pulses emitted by the transducer array 3104 propagate through the platen 3102 toward the top surface 3112 of the platen 3102 along the +z direction (see right-hand coordinate system 3120). The top surface 3112 is a boundary between materials having different mechanical impedances (e.g., density and / or stiffness). Therefore, the ultrasonic pulse will be reflected from the top surface 3112, and the resulting reflection will propagate through the platen 3102 toward the bottom surface 3122 along the -z direction, where it is detected by the transducer array 3104. This reflection is also referred to as an echo.

[0253] The ultrasonic transducer array 3104 can be row-column addressable. Specifically, the transducer array 3104 has a plurality of row electrodes 3106 extending along the y direction and a plurality of column electrodes 3108 extending along the x direction. There is a piezoelectric layer 3114 between the row electrodes 3106 and the column electrodes 3108 in the z direction, and the piezoelectric layer can be electrically driven via the row electrodes 3106 and the column electrodes 3108 so that it generates mechanical oscillations, thereby transmitting ultrasonic waves into the platen 3102. Similarly, when the piezoelectric layer 3114 is mechanically driven by ultrasonic waves, it generates a time-varying electrical signal, which can be subsequently detected and processed. The piezoelectric layer 3114 can be formed of a crystal (e.g., lithium niobate, lithium tantalate, quartz, etc.), a ceramic (e.g., zinc oxide, lead zirconate titanate, potassium niobate, barium titanate, etc.), a III-V or II-VI semiconductor (e.g., aluminum nitride, gallium arsenide, etc.), a polymer, and / or any other piezoelectric material.

[0254] Figure 2 The i-th row electrode 3106(i) is shown causing the piezoelectric layer 3114 to transmit an ultrasonic pulse 3116(i) into the platen 3102. Since the row electrodes 3106(i) extend the entire length of the ultrasonic sensor 3100 (in the y-direction), the ultrasonic pulse 3116(i) similarly extends the entire length of the platen 3102. Alternatively, the j-th column electrode 3108(j) can cause the piezoelectric layer 3114 to transmit an ultrasonic pulse 3118(j) into the platen 3102. Since the column electrodes 3108(j) extend the entire width of the ultrasonic sensor 3100 (in the x-direction), the ultrasonic pulse 3118(j) similarly extends the entire width of the platen 3102. In operation, either the row electrode 3106(i) or the column electrode 3108(j) causes ultrasound pulses to be transmitted (e.g., via a signal applied to the electrode), while the other of the electrodes 3106(i) or 3108(j) is configured to record received ultrasound pulses. The lateral area (i.e., in the xy plane) where the row electrode 3106(i) and the column electrode 3108(j) overlap is referred to herein as a pixel element (e.g., see Figure 3 Pixel element 3110 in). Although Figure 2 A transducer array 3104 is shown having 19 row electrodes 3106 and 17 column electrodes 3108 (corresponding to 19×17=323 pixel elements), but the transducer array 3104 may alternatively have any number of row electrodes 3106 and column electrodes 3108 without departing from the scope of this document. For example, the transducer array 3104 may have 512 row electrodes 3106 and 512 column electrodes 3108, corresponding to 512×512=262,144 pixel elements. In some embodiments, there is no minimum and / or maximum number of row electrodes 3106 and / or column electrodes 3108 applicable to the sensors contemplated by the present invention.

[0255] like Figure 3 As shown, the pressure plate 3102 has a thickness d in the z direction. p Since the pixel element 3110 is used for both transmitting and sensing ultrasonic waves, the thickness d can be selected to be p , so that the duration of the emitted pulse is less than the round-trip propagation time t in the pressure plate 3102 p This requirement ensures that the pixel element 3110 does not emit and sense simultaneously and that electrical leakage (see, for example, Figure 6 Leakage in 3502) will not contaminate the output signal. For example, the pressure plate 3102 can be controlled by the sound velocity v s The pulse has a bandwidth of 45 MHz and a bandwidth-limited duration of 22 ns, corresponding to sound propagating 132 μm in the z direction (e.g., propagating back and forth in a platen 3102 with a thickness of 66 μm). However, the pulse can have a larger spatial extent, which can simplify signal processing (e.g., see Figure 6 In some embodiments, the thickness d of the pressing plate 3102 p However, the pressing plate 3102 may have a different thickness d p Similarly, the platen 3102 may be made of materials other than glass (eg, plastic, metal, crystal, semiconductor, etc.) without departing from the scope of this document.

[0256] When one or more user's fingers and / or other tissues (shown as finger 3130) physically contact the top surface 3112 of the pressure plate 3102, the ultrasonic sensor 3100 can be used to (i) detect the presence of the finger 3130, (ii) image the fingerprint of the finger 3130, (iii) measure the force of the finger 3130 pushing against the top surface 3112, (iv) measure the time variation of the force to determine that the finger 3130 is from a living person (not a prosthesis), and / or any combination of these. Therefore, the ultrasonic sensor 3100 can be used as a biometric touch sensor (e.g., see Figure 8 In order to detect a complete fingerprint, the ultrasonic sensor 3100 may have a resolution of at least 0.1 cm. 2 、0.3cm 2 , 0.5cm 2 、0.7cm 2 and / or 1cm 2 For clarity, Figure 2 and Figure 3 Finger 3130 is not drawn to scale and may include fingers, palms, other body parts, and / or any other tissue of one, two, or more users of the systems, devices, and methods of the present inventive concept.

[0257] Figure 4 and Figure 5 The diagram illustrates the row and column addressing of the ultrasonic sensor 3100 when the finger 3130 contacts the pressure plate 3102. Figure 4 In FIG. 3 , column electrodes 3108(j) emit ultrasonic pulses 3118(j) into platen 3102. Figure 5 , row electrodes 3106 ( i ) sense echoes 3406 , 3408 generated when an ultrasonic pulse 3118 ( j ) is reflected from the top surface 3112 . Figure 4 and Figure 5 are side cross-sectional views through row electrode 3106(i). Figure 4 and Figure 5 In FIG. 3 , only ten column electrodes 3108 are shown. This is best viewed together with the following description. Figure 4 and Figure 5 .

[0258] The bottom surface of the finger 3130 forms an alternating sequence of ridges 3316 (also referred to as "friction ridges" or "epidermal ridges") and valleys 3318. The ridges 3316 directly contact the top surface 3112 of the platen 3102, while the valleys 3318 do not directly contact the top surface 3112. Thus, under each valley 3318, air is in contact with the top surface 3112. Therefore, the reflection coefficient at the top surface 3112 is larger at the valleys 3318 and smaller at the ridges 3316, so the amplitude of the echo 3408 is greater than the amplitude of the echo 3406.

[0259] During transmission, the signal source 3304 applies a drive signal 3306 to the column electrode 3108 (j), while all other column electrodes 3108 and all row electrodes 3106 are grounded, thereby establishing a voltage difference across the piezoelectric layer 3114. For clarity, Figure 4 Only the row electrode 3106(i) is shown to be grounded. During sensing, the amplifier 3402 amplifies the electrical output of the row electrode 3106(i) into an amplified output 3404, which is subsequently digitized and processed. Transmitting with the column electrode 3108(j) and sensing with the row electrode 3106(i) is equivalent to imaging the finger 3130 with a single pixel element 110(i,j). Therefore, the image of the finger 3130 can be captured by repeating the transmission and sensing for all combinations of the row electrode 3106 and the column electrode 3108. Alternatively, the transmission can be performed with the row electrode 3106 and the sensing can be performed with the column electrode 3108.

[0260] Figure 6 Waveform 3500W is shown recorded from row electrode 3106(i) during emission and sensing of one pixel element 3110. Waveform 3500W is obtained by digitizing amplified output 3404 (see, e.g., Figure 8 The signal values ​​are also time-stamped. At the transmission start time t=0, the drive signal 3306 is applied to the column electrode 3108(j) to generate an ultrasonic pulse 3118(j). Figure 6 In the example of , the drive signal 3306 is a pulse having a center frequency of 150 MHz and a duration of eight cycles of the center frequency (ie, approximately 53 ns). The emission start time t=0 serves as the reference time for all time measurements of the waveform 3500W.

[0261] When drive signal 3306 is applied to column electrode 3108(j), RF leakage 3502 appears on waveform 3500W due to capacitive coupling between electrodes 3106(i) and 3108(j). RF leakage 3502 disappears within 150ns, after which an echo (e.g., Figure 5 The portion of waveform 3500W with the echo is referred to herein as a "sub-waveform" and is Figure 6 3502. The ultrasonic sensor array 3100 and the drive signal 3306 are designed so that the propagation time of the pulse 3118(i) through the platen 3102 is greater than the time required for the RF leakage 3502 to disappear. This requirement allows the sub-waveform 3504 to be distinguished from the RF leakage 3502 and prevents the RF leakage 3502 from contaminating or affecting the sub-waveform 3504. Note that RF leakage 3502 does not always occur, depending on the specific implementation of the ultrasonic sensor array 3100. If RF leakage 3502 does not occur, or if RF leakage 3502 occurs but is smaller than Figure 6 If the thickness of the substrate 3102 disappears faster than shown, the pressure plate 3102 can be made thinner.

[0262] Figure 6 Sub-waveform 3504 is shown occurring at an arrival time t measured relative to the transmit reference time t=0. a Arrival time t a The arrival time t may be defined relative to any feature of the sub-waveform 3504, such as the start or end point of the sub-waveform 3504, the peak of an envelope calculated from the sub-waveform 3504 (e.g., via a Hilbert transform applied to the sub-waveform 3504), the zero crossing of the instantaneous phase calculated from the sub-waveform 3504, and / or the peak or zero crossing of any oscillation of the sub-waveform 3504. a It may alternatively or additionally be defined relative to any phase of any oscillation of the sub-waveform 3504. The arrival time t a The waveform 3500W is processed to determine the arrival time t a The method depends on the definition chosen and is described in more detail below.

[0263] Arrival time t a Some definitions are based on the zero crossing of the waveform 3500W. To facilitate the determination of t in these cases a, the mean of waveform 3500W can be calculated and subtracted from waveform 3500W. The result is referred to herein as a "mean-corrected waveform". Waveform 3500W is an example of a mean-corrected waveform, as evidenced by the fact that waveform 3500W is generally centered around a 0 mV signal. In addition, since only zero crossings need to be detected near or within sub-waveform 3504, waveform 3500W can be windowed to extract sub-waveform 3504. The mean of sub-waveform 3504 can be calculated and subtracted from sub-waveform 3504. The result is referred to herein as a "mean-corrected sub-waveform", of which sub-waveform 3504 is an example. Windowing eliminates a large portion of waveform 3500W, thereby advantageously speeding up signal processing and reducing the memory required for an associated device or system. In some embodiments, recording of the waveform begins after the emission start time, in which case part or all of waveform 3500W before sub-waveform 3504 can be ignored.

[0264] exist Figure 6 , the echo represented by sub-waveform 3504 is the initial echo of ultrasound pulse 3118 (j). Specifically, the time delay between the start of pulse transmission (i.e., t=0) and the start of the sensed echo (i.e., the start of sub-waveform 3504) is approximately the round-trip propagation time t p =2d p / v s The echo reflects from the bottom surface 3122 to produce another upwardly propagating pulse, which in turn reflects from the top surface 3112 to produce a second downwardly propagating echo, which is transmitted from 2t p This process is repeated continuously, generating a sequence of sensed echoes, the time interval between these echoes is t p , and the amplitude decreases with each reflection (i.e., position in the sequence). The sub-waveform 3504 of the initial echo has the largest amplitude (i.e., the highest SNR). Therefore, it is assumed herein that the sub-waveform 3504 represents the initial echo. However, embodiments of the present invention can be easily adapted to record and process the second echo, the third echo, and so on.

[0265] Figure 7 The time offset Δt between the baseline sub-waveform 3602 and the signal sub-waveform 3604 is illustrated. Each of the sub-waveforms 3602 and 3604 is an example of the mean correction sub-waveform 3504. Figure 7 In FIG. 3 , for clarity, sub-waveforms 3602 and 3604 are normalized and superimposed on the same figure. To enhance the visibility of the time offset Δt, only the 7 ns wide portion of sub-waveforms 3602 and 3604 is plotted.

[0266] Baseline sub-waveform 3602 is recorded by pixel element 3110 when air is in contact with top surface 3112 of platen 3102 in the region directly above pixel element 3110 (e.g., below valley 3318 of finger 3130, or when finger 3130 is completely off platen 3102). In contrast, signal sub-waveform 3604 is recorded when ridge 3316 of finger 3130 contacts top surface 3112 in the region directly above pixel element 3110. Figure 7 As shown, the presence of ridge 3316 on top surface 3112 not only reduces the normalized amplitude of baseline sub-waveform 3604 by ΔA, but also shifts baseline sub-waveform 3604 by Δt. Therefore, the presence or absence of ridge 3316 can be determined from Δt.

[0267] In some embodiments, the drive signal 3306 has the form of a tone pulse, i.e., several consecutive cycles of a single-frequency sine wave. The sub-waveform 3504 also has the form of a tone pulse and can therefore be described using phase rather than time. In these cases, the arrival time t a is equivalent to the arrival phase, so the time offset Δt is equivalent to the phase offset Δφ. That is, the presence of the ridge 3316 on the top surface 3112 shifts the phase of the baseline sub-waveform 3604 by Δφ=fΔt×360°, where f is the frequency of the sine wave, and 360° converts the result to degrees. Therefore, in the present disclosure, when the sub-waveform 3504 has a well-defined phase and frequency, any reference to the time offset Δt is equivalent to the phase offset Δφ (and vice versa). However, the drive signal 3306 need not be a tone pulse, but can instead be a different type of pulse and / or excitation waveform.

[0268] The time delay Δt can be positive or negative. In fact, the sign of Δt can be used to identify whether the material in contact with the pressure plate 3102 is softer or harder than the material of the pressure plate 3102. Therefore, the sign of Δt can also be used to determine the type of object contacting the pressure plate 3102.

[0269] Figure 8 31 is a block diagram of a finger sensor system 3700 that uses an ultrasonic sensor array 3100 to image a finger 3130 based on a time offset Δt. The finger sensor system 3700 can also determine the presence or absence of a finger 3130 on the platen 3102 and determine the force with which the finger 3130 pushes against the platen 3102.

[0270] The finger sensor system 3700 includes a real-time processor 3708 that controls a multiplexer (MUX) 3702 to select which column electrode 3108 is driven by the signal source 3304. The real-time processor 3708 also controls the MUX 3702 to select which row electrode 3106 is connected to the input of the amplifier 3402. The amplified output 3404 of the amplifier 3402 is digitized using an analog-to-digital converter (ADC) 3706, the output of which is sensor data 3716, which is then time-stamped by the real-time processor 3708 to create the waveform 3500W. The real-time processor 3708 references a time base 3728, which references all timing of the waveform 3500W, thereby ensuring that the time stamps of all waveforms 3500 are accurate and stable. Although Figure 8 Not shown, but time base 3728 may also be used as a time / frequency reference for one or both of ADC 3706 and signal source 3304.

[0271] Processor 3708 comprises a "real-time" processor because the time it takes to complete an operation is deterministic and therefore predictable (i.e., does not change based on external factors or unexpected events). Real-time control of MUX 3702 and processing of amplified output 3404 ensures that time stamping is consistently performed for all waveforms 3500. This consistency is important because each time offset Δt is determined from two waveforms 3500 recorded at different times. Sporadic or unpredictable delays in signal processing, control of MUX 3702, or both may result in an erroneous value for the time offset Δt, i.e., the time offset Δt will be incorrectly attributed to the presence or absence of a finger 3130 on the platen 3102. Examples of real-time processor 3708 include field-programmable gate arrays (FPGAs), digital signal processors (DSPs), and system-on-chips (SoCs). However, real-time processor 3708 may be other types of circuits and / or chips as long as it operates deterministically. After waveform 3500W is generated, it may be processed non-deterministically to determine the time offset Δt. Thus, processor 3720 need not be a real-time processor (eg, it may be a central processing unit).

[0272] The real-time processor 3708 sends the waveform 3500W to the computer 3710, which processes the waveform 3500W to determine the time offset Δt. The computer 3710 includes a processor 3720 and a memory 3722 that stores the waveform 3500W. The memory 3722 also stores machine-readable instructions that, when executed by the processor 3720, process the waveform 3500W to determine the time offset Δt from the sensor data 3716. The signal processing method used by the computer 3710 to determine the time offset Δt will be discussed in more detail below. Additional details about the computer 3710 will be discussed below in connection with Fig.19 Give a description.

[0273] In some embodiments, the finger sensor system 3700 generates a time-shifted image from the time shift Δt determined for each pixel element 3110 of the sensor array 3100 (see, for example, Fig. 9 3804 in the time-shifted image). Each pixel of the time-shifted image uniquely corresponds to a pixel element 3110, and the pixels of the time-shifted image are arranged in the same manner as the pixel elements 3110. Computer 3710 can display the time-shifted image to a user via display screen 3712, which can be integrated with computer 3710 (e.g., a tablet device or laptop computer) or can be separate from computer 3710 (e.g., a desktop monitor or high-definition television). Although in Figure 8 3708 and computer 3710 are combined into a single computer system.

[0274] The waveform 3500W recorded by the finger sensor system 3700 when the finger 3130 contacts the pressure plate 3102 is referred to herein as a "signal waveform". The finger sensor system 3700 may sequentially record one signal waveform 3500W for each pixel element 3110 of the ultrasonic sensor array 3100. In some embodiments, the finger sensor system 3700 uses the waveform 3500W obtained when the finger 3130 is not in contact with the pressure plate 3102 (i.e., the air is completely in contact with the top surface 3112 of the pressure plate 3102) to determine the time offset Δt for each pixel element 3110. Such a waveform 3500W is referred to herein as a "baseline waveform".

[0275] Finger sensor system 3700 processes the signal and baseline waveform 3500 of each pixel element 3110 to determine the time offset Δt of the pixel element 3110. For example, finger sensor system 3700 may process signal waveform 3500W to determine the signal arrival time of the signal echo And process the baseline waveform 3500W to determine the baseline arrival time of the baseline echo The finger sensor system 3700 can then calculate the signal arrival time from Subtract the baseline arrival time To get the time offset In other embodiments, the finger sensor system 3700 transforms the signal waveform and the baseline waveform 3500 into a cross-correlation waveform. The finger sensor system 3700 then processes the cross-correlation waveform (eg, by identifying peaks) to determine the time offset Δt.

[0276] The signal arrival time from each pixel element 3110 of the ultrasonic sensor 3100 Subtract the baseline arrival time This is referred to as time (or phase) compensation. Advantageously, time compensation improves accuracy by ensuring that the spatial variations in the detected time offset Δt are correctly attributed to the ridges 3316 and valleys 3318 of the finger 3130 on the platen 3102. Specifically, baseline time compensation is based on the round-trip propagation time on the sensor 3100. The spatial variability of s , thickness d p or both spatial variations, for different pixel elements 3110, t p Subject to change. p The spatial variability of may be caused by manufacturing limitations, such as when the top and bottom surfaces 3112, 3122 of the platen 3102 are not flat or parallel to each other when manufactured, or when the frequency / phase response of the piezoelectric layer 3114 varies spatially across the platen 3102. p The spatial variability of can also be caused by differential thermal expansion of the platen 3102, which can be caused by lateral temperature gradients across the platen 3102. Such temperature gradients can be caused by heat conducted from the finger 3130 into the platen 3102. The thermal gradients can also cause spatial variations in the density of the platen 3102, resulting in a change in the speed of sound v s The round trip time t p Spatial variability may also be caused by the electronic device, such as different delays of different circuit components, different lengths of metal traces, changes in channel impedance, and / or other inconsistencies within the electronic device that may cause spatial variability.

[0277] Due to the spatial variation tp Many sources of spatial variability are time-dependent, so the most accurate value of Δt can be determined from signals and baseline waveform 3500 recorded close in time to each other (e.g., within one second). However, many sources of spatial variability change slowly enough in time that the baseline arrival time The time-shifted image may be substantially constant over a longer period of time (e.g., several minutes or longer). In this case, it may not be necessary to record a complete set of baseline waveforms 3500 (i.e., one for each pixel element 3110) for each time-shifted image. For example, the baseline waveforms 3500 may be recorded once, saved in the memory 3722, and then retrieved from the memory 3722 as needed. In this case, the finger sensor system 3700 may periodically (e.g., once per minute) record a new baseline waveform 3500 and overwrite the baseline waveform 3500 stored in the memory 3722 with the new baseline waveform 3500. Alternatively, only the baseline arrival time is stored in memory 3722 and retrieved from memory 3722 as needed to determine the time delay Δt. In contrast to storing the baseline waveform 3500, only the baseline arrival time is stored. Less memory is used, thereby reducing the computational resources required to generate the time-shifted image.The stored baseline waveform 3500 may also be corrected for temperature changes that have occurred since the baseline waveform 3500 was recorded, thereby extending the amount of time that can elapse before a new baseline waveform 3500 is recorded.

[0278] Fig. 9 The time-shifted image 3804 of a fingerprint is compared to the conventional amplitude-shifted image 3802 of the same fingerprint. To improve the signal-to-noise ratio (SNR), each image 3802 and 3804 is averaged over 16 scans. The ultrasonic sensor 3100 has 250×250=62,500 pixel elements 3110 covering an area of ​​1×1 cm 2 Images 3802 and 3804 are obtained from the same signal and baseline waveform 3500. To generate amplitude shift image 3802, the signal and baseline waveform 3500 of each pixel element 3110 are processed to determine the average amplitude shift therebetween (see, e.g., Figure 7 3804 ). Each average amplitude shift is mapped to a grayscale value of a corresponding pixel of image 3802 . For time-shifted image 3804 , the average time shift Δt determined for each pixel element 3110 is mapped to a grayscale value of a corresponding pixel of image 3804 .

[0279] Subtracting the baseline amplitude from the signal amplitude of each pixel element 3110 of the ultrasonic sensor 3100 is called baseline amplitude (or power) compensation. Similar to baseline time compensation, baseline amplitude compensation is used to correct for the spatial variability of the sensed amplitude (or power) of the echo, thereby ensuring that the spatial variation of ΔA is correctly attributed to the finger 3130. In fact, the spatial variation of the baseline echo amplitude may be greater than the amplitude offset ΔA, in which case baseline amplitude compensation is essential to obtain a clear fingerprint image. Spatial amplitude variability can be caused by any of several factors, including spatial variations in the piezoelectric properties of the piezoelectric layer 3114, electrical variations in the electrodes 3106 and 3108, and readout electronics.

[0280] The SNR of the time-shifted image 3804 is significantly higher than that of the amplitude-shifted image 3802, as evidenced by the significant improvement in the contrast of the ridges. This improvement in SNR may indicate that the ultrasound pulses 3116 were generated with less phase noise than amplitude noise, so that the measurement sensitivity of phase (or time delay) may be better than that of amplitude. Fig. 9 As shown, the higher SNR achievable using the inventive concept can be used to improve image clarity. However, the higher SNR can also advantageously shorten the data acquisition time by reducing the number of averages required to achieve the target SNR. For example, each pixel element 3110 can be scanned using a time period of at least 1 μs, so a comprehensive scan of all 62,500 pixel elements 3110 will occur over a time period of at least 62.5 ms. However, for amplitude offset imaging, up to 64 scans can be performed and averaged to obtain an image with sufficient SNR, so the total scan time is at least 4 s. In contrast, for time offset imaging, sufficient SNR can be obtained by averaging on less than 64 scans (e.g., less than 16 scans, less than 8 scans, such as only 4 scans). The total scan time of the four scans thus obtained is 0.25 s, which is sixteen times less than the time required for amplitude offset imaging. In some embodiments, time offset imaging is achieved using any positive integer number of scans averaged together. These embodiments include time offset imaging of a single scan, in which case averaging is not required.

[0281] The time-shifted image 3804 and the amplitude-shifted image 3802 can be combined to obtain a mixed time-amplitude-shifted image, whose SNR is higher than either of the images 3802 and 3804. Specifically, each pixel of the mixed image can be obtained by processing the corresponding signal and the baseline waveform 3500 to obtain both the time shift Δt and the amplitude shift Δt. These shifts can then be transformed into a single value (e.g., a weighted sum) and then mapped to a grayscale value. Other techniques can also be used to combine the time shift Δt and the amplitude shift ΔA without departing from the scope of this document. In some embodiments, either or both of the time-shifted image 3804 and the amplitude-shifted image 3802 can be obtained, and the device (e.g., the user device 500 described herein) can be configured to first create one or more time-shifted images or amplitude-shifted images to identify the position of the finger (e.g., on the sensor), and then create one or more amplitude-shifted images or time-shifted images, respectively, which are used by the device to create a fingerprint of the finger. Alternatively or additionally, the device may be configured to create either or both of a time-shifted image and / or an amplitude-shifted image based on a configuration input by a user or a condition recognized by the device (e.g., automatically recognized). For example, if one type of image (e.g., a fingerprint) does not provide sufficient and / or appropriate data (e.g., for user recognition), the device may automatically switch to obtaining another type of image. For example, an indication that one or more fingerprint ridges and / or valleys are missing may result in a transition from one type of image capture (e.g., a time-shifted image or an amplitude-shifted image) to another type of image capture (e.g., an amplitude-shifted image or a time-shifted image, respectively), and / or from a single type of image capture (e.g., a time-shifted image or an amplitude-shifted image) to a combination of multiple types of image capture (e.g., a combination of a time-shifted image and an amplitude-shifted image). In another example, one type of image (e.g., a time-shifted image or an amplitude-shifted image) is used to identify the periphery of a finger placed adjacent to the sensor 3100, while another type of image (e.g., an amplitude-shifted image or a time-shifted image, respectively) is used to capture the fingerprint of the finger (e.g., to improve the response time of fingerprint recognition).

[0282] Fig.10 shows the signal arrival time using only the signal waveform 3500 Generated fingerprint image 3902. Thus, Fig.10 The fingerprint image 3902 is generated without baseline compensation (i.e., baseline waveform 3500). Specifically, the signal arrival time determined for each pixel element 3110 of the ultrasonic sensor 3100 is The grayscale values ​​of the corresponding pixels are mapped to the fingerprint image 3902. The fingerprint image 3902 is obtained from the Fig. 9 Images 3802, 3804 are created from the same signal waveform 3500.

[0283] Fig.10 Also shown is a binarized image 3904 obtained by applying binarization to the fingerprint image 3902. The binarized image 3904 shows almost all of the same features that appeared in the time-shifted image 3804. Therefore, the round-trip propagation time t p The spatial variability of may be small enough that no baseline time compensation is required. For example, the thickness d of the platen 3102 p may have sufficient spatial uniformity so that for all pixel elements 3110, the baseline arrival time In this case, the baseline waveform 3500 is not required, thereby advantageously shortening data acquisition time, speeding up signal processing, and reducing memory storage requirements.

[0284] Fig.11 31000 is a flow chart of a method 31000 for processing an ultrasound signal using baseline time compensation. The method 31000 may be performed using the systems and devices of the present invention and described using the various components described herein. In block 31012, a time offset between (i) a signal arrival time of a signal echo sensed by the ultrasound transducer and (ii) a baseline arrival time of a baseline echo sensed by the ultrasound transducer is determined. In one example of block 31012, the ultrasound transducer is a pixel element 3110 (i, j) of the ultrasound sensor 3100, and Figure 8 The computer 3710 processes the signal and baseline waveform 3500 to determine the time offset Δt. The signal echo may be generated by the platen surface when an object is in contact with the platen surface. Similarly, the baseline echo may be generated by the platen surface when no object is present. For example, Figures 2 to 5 As shown, the signal and baseline echo may be generated by the platen top surface 3112 of the platen 3102 .

[0285] In some embodiments, the ultrasonic transducer is a pixel element of an ultrasonic transducer array. In these embodiments, the method 31000 includes a decision block 31020 that repeats block 31012 for each pixel element of the ultrasonic transducer array to generate a time-shifted array. The method 31000 also includes a block 31022, in which a time-shifted image is generated for the time-shifted array. In one example of blocks 31020 and 31022, the computer 3710 processes the signal and baseline waveform 3500 to determine a time offset Δt for each pixel element 3110 of the ultrasonic sensor array 3100. A time offset Δt is one of an array of time offsets corresponding to the two-dimensional array of pixel elements 3110. The computer 3710 then processes the array of time offsets to create a time-shifted image (e.g., Fig. 9time-shifted image 3804). Although Fig. 9 Not shown, but the time-shifted image can subsequently be output (e.g., to display screen 3712 or to another computer system for additional processing or storage).

[0286] In some embodiments, the ultrasound transducer array has a number of rows (conductor rows) and a number of columns (conductor columns), and the time-shifted image has the same number of rows and columns. For example, the number of rows and columns in the time-shifted image 3804 may be equal to the number of rows and columns of the ultrasound sensor 3100. In this case, the pixels of the time-shifted image may have a one-to-one correspondence with the pixel elements 3110 of the sensor 3100.

[0287] In some embodiments, method 31000 also includes post-processing of the time-shifted image (e.g., post-processing of the time-shifted image data). For example, the post-processing may include applying one or more of the following to the time-shifted image: Wiener filtering, steerable filtering, histogram equalization, and / or binarization. In some embodiments, binarization is applied to the fingerprint image 3902 to generate a binarized image 3904. However, any type of image post-processing may be implemented without departing from the scope of this document. Details on various post-processing techniques may be found in "A row-column addressed acoustic biometric scanner integrated with pulse oximetry" by Gerard Touma (Stanford University Ph.D. dissertation, 2020).

[0288] In some embodiments, method 31000 includes one or both of blocks 31008 and 31010. In block 31008, a baseline echo is identified from a baseline waveform obtained from an ultrasonic transducer while the object is in contact with the platen surface. In block 31010, a signal echo is identified from a signal waveform obtained from an ultrasonic transducer while the object is not in contact with the platen surface. The signal echo may be an initial echo of the signal waveform, and the baseline echo may be an initial echo of the baseline waveform. Waveform 3500W is an example of a waveform that may be a signal waveform or a baseline waveform. Sub-waveform 3504 is an example of an initial echo.

[0289] In some embodiments, block 31012 of method 31000 includes blocks 31014, 31016, and 31018. In block 31014, the signal waveform is processed to identify the signal arrival time. In block 31016, the baseline waveform is processed to identify the baseline arrival time. In block 31018, the baseline arrival time is subtracted from the signal arrival time to determine the time offset. Prior to identifying the signal arrival time, the signal waveform may be filtered. Similarly, prior to identifying the baseline arrival time, the baseline waveform may be filtered.

[0290] The foregoing embodiments of method 31000 may be executed on a computer system (eg, see Fig.19 The method 31000 may be performed by a third party and may include an ultrasonic signal processing system 31800, such as a computer system that receives the signal recorded by the finger sensor system 3700 and the baseline waveform 3500. The third party may operate the finger sensor system 3700 and send the recorded waveform 3500 to the computer system for processing. Thus, an ultrasonic sensor is not required to perform the method 31000. However, the following discussion describes other embodiments of the method 31000 that include operation of an ultrasonic sensor to obtain a waveform.

[0291] Therefore, some embodiments of method 31000 include blocks 31002 and 31004. In block 31002, a signal ultrasonic pulse is sent into a platen by an ultrasonic transducer so that a portion of the signal ultrasonic pulse is reflected from a surface of the platen to form a signal echo. In block 31004, the signal echo is sensed using the ultrasonic transducer. Then, the output of the ultrasonic sensor can be processed into a signal waveform. For example, in Figure 8 In the example, the amplifier 3402 amplifies the output of the sensor array 3100 into an amplified output 3404, the ADC 3706 digitizes the amplified output 3404 into sensor data 3716, and the real-time processor processes the sensor data 3716 into a waveform 3500 W. Although the ultrasound transducer in this example is an array of multiple pixel elements, the ultrasound transducer may alternatively be a single ultrasound transducer.

[0292] In some embodiments, the ultrasonic transducer includes one or more pixel elements of an ultrasonic transducer array. In these embodiments, the method 31000 may include a decision block 31006 that repeats blocks 31002 and 31004 for each pixel element of the transducer array. If the pixel elements of the transducer array are row-column addressable, a signal ultrasonic pulse can be sent and a signal echo can be sensed by controlling the ultrasonic transducer array via row-column addressing. Only one row of the sensor array can be used to send a signal ultrasonic pulse, and only one column of the sensor array can be used to sense an echo pulse. In one example of these embodiments, the column electrode 3108 (j) of the ultrasonic sensor 3100 is excited to send an ultrasonic pulse 3118 (j) into the platen 3102. The ultrasonic pulse 3118 (j) is reflected from the top surface 3112 of the platen 3102 to generate echoes 3406, 3408, which are then sensed by the row electrode 3106 (i).

[0293] In other embodiments, the ultrasonic transducer array has individually addressable pixel elements. In these embodiments, by addressing individual pixel elements, signal ultrasonic pulses can be sent and signal echoes can be sensed. In some embodiments, beamforming can be used to send signal ultrasonic pulses, that is, multiple pixel elements can be excited simultaneously, and complex-valued weights are appropriately selected to focus the signal ultrasonic pulses onto the top surface of the pressure plate. Similarly, beamforming can also be used to sense signal echoes, that is, multiple pixel elements can be sensed simultaneously, and appropriate complex-valued weights are applied to the electrical outputs of the pixel elements. Beamforming can be implemented using both row-column addressable sensor arrays and individually addressable sensor arrays. Once the detected data is digitized and stored in a computer, software can also be used to implement beamforming on the detected data (for example, see Fig.19 An ultrasonic signal processing system 31800) is provided to replace the use of hardware for beamforming for both or either of the transmit and receive operations.

[0294] In the aforementioned embodiments of method 31000 including blocks 31002 and 31004, the baseline waveform may be stored in a memory and retrieved from the memory as part of block 31012. However, in other embodiments, method 31000 iterates blocks 31002 and 31004 twice. Specifically, method 31000 iterates blocks 31002 and 31004 for a first time to measure the signal waveform, as described above. In a second iteration of blocks 31002 and 31004, a baseline ultrasonic pulse is sent into the platen by an ultrasonic transducer so that a portion of the baseline ultrasonic pulse is reflected from the platen surface to form a baseline echo. The baseline echo is then sensed using an ultrasonic transducer. The output of the ultrasonic sensor may subsequently be processed into a baseline waveform, similar to the signal waveform. The baseline waveform may be generated before or after the signal waveform.

[0295] In an embodiment where the ultrasonic transducer is a pixel element of an ultrasonic transducer array, the method 31000 includes a block 31006 to repeat blocks 31002 and 31004 for each pixel element of the transducer array. Specifically, the method 31000 performs a first iteration of blocks 31002, 31004, and 31006 to measure a signal waveform for each pixel element. Then, the method 31000 performs a second iteration of blocks 31002, 31004, and 31006 to measure a baseline waveform for each pixel element. The transducer array can be controlled to send a baseline ultrasound pulse, similar to the way it is controlled to send a signal ultrasound pulse (e.g., row and column or individual pixel addressing, beamforming or single row transmission, etc.). Similarly, the transducer array can be used to sense a baseline echo, similar to the way it is used to sense a signal echo (e.g., row and column or individual pixel addressing, beamforming or single column sensing, etc.). The signal waveform and the baseline waveform can be obtained in any time sequence. For example, all signal waveforms may be acquired before all baseline waveforms are acquired, or vice versa.

[0296] Signal Processing to Determine Time Offset

[0297] Fig.12 is a flow chart of method 31100 for processing a waveform to identify an arrival time of an echo. When method 31100 is performed using a signal waveform to identify a signal arrival time, method 31100 may replace block 31014 of method 31000. Similarly, when method 31100 is performed using a baseline waveform to identify a baseline arrival time, method 31100 may replace block 31016 of method 31000.

[0298] In block 31108 of method 31100, the waveform is processed to identify the zero crossing of the echo. In block 31110, the arrival time of the echo is calculated based on the time of the zero crossing. Blocks 31108 and 31110 can be performed using the signal waveform to calculate the signal arrival time. Blocks 31108 and 31110 may also be performed using the baseline waveform to calculate the baseline arrival time The baseline arrival time can be determined Determine signal arrival time before or after

[0299] Some embodiments of method 31100 include block 31104, where the mean of the waveform is subtracted from the waveform to obtain a mean-corrected waveform. In these embodiments, blocks 31108 and 31110 are performed using the mean-corrected waveform, i.e., the identified zero crossings are zero crossings of the mean-corrected waveform. In some of these embodiments, method 31100 includes calculating the mean of the waveform.

[0300] Some embodiments of method 31100 include block 31102, where a sub-waveform of an echo is selected from the waveform. Figure 6 An example of a sub-waveform is sub-waveform 3504. In this case, block 31104 is performed with the sub-waveform (i.e., the mean of the sub-waveform is subtracted from the sub-waveform) to obtain a mean-corrected sub-waveform. Blocks 31108 and 31110 are then performed with this mean-corrected sub-waveform (i.e., the zero crossings are the zero crossings of the mean-corrected sub-waveform). Figure 7 The mean-corrected sub-waveforms 3602 and 3604 of are examples of mean-corrected baseline sub-waveforms and mean-corrected signal sub-waveforms, respectively. In one of these embodiments, the method 31100 includes calculating the means of the sub-waveforms.

[0301] Some embodiments of method 31100 include block 31106, wherein the mean syndrome waveform is interpolated to obtain a best fit curve. In these embodiments, blocks 31108 and 31110 are performed using the best fit curve (i.e., the zero crossing is the zero crossing in the best fit curve). The entire mean syndrome waveform may be interpolated, or a portion thereof may be interpolated. For example, a portion of the mean syndrome waveform 3602 near the zero crossing 3610 may be selected for linear interpolation, while other portions (e.g., near adjacent antinodes) may be excluded. Excluding these other portions advantageously speeds up the interpolation by reducing the amount of data that needs to be processed.

[0302] like Figure 6 As shown, sub-waveform 3504 lasts for several cycles, thereby forming a sequence of zero crossings. Any one or more of these zero crossings can be used to determine the signal arrival time of the echo. The sequence of zero crossings can include only zero crossings with positive slopes, only zero crossings with negative slopes, or both. In some embodiments, the sequence of signal zero crossings is processed to determine the signal arrival time, and the sequence of baseline zero crossings is similarly processed to determine the baseline arrival time. Similar processing of these two sequences ensures that the definition of arrival time is the same for the baseline and signal echo. For example, in the case where only one baseline zero crossing is used to determine the baseline arrival time and only one signal zero crossing is used to determine the signal arrival time In an embodiment of the present invention, the position of the baseline zero-crossing point in the baseline zero-crossing point sequence may be the same as the position of the signal zero-crossing point in the signal zero-crossing point sequence.

[0303] In some embodiments of method 31000, in block 31014, the signal waveform is processed to identify the signal arrival time by applying a Hilbert transform to at least a portion of the signal waveform (e.g., a portion or all of a signal sub-waveform). The output of the Hilbert transform includes a time series of instantaneous signal phases, which can be processed to identify signal zero crossings. The signal transmission time can then be calculated based on the time at which the signal zero crossing occurs. The same steps can also be implemented in block 31016, but the baseline waveform is used instead of the signal waveform to calculate the baseline arrival time. Any of the techniques described above for method 31100, such as selecting sub-waveforms, interpolating, subtracting means, and the like, can be implemented using a sequence of instantaneous signal phases and a sequence of instantaneous baseline phases.

[0304] The Hilbert transform may also output a time series of envelope values, which may also be used to determine the echo arrival time. For example, an extreme value may be identified in the sequence of envelope values, and the time at which the extreme value occurs may be selected as the arrival time. The sequence of envelope values ​​may be interpolated to more accurately identify the time at which the extreme value occurs. The sequence of envelope values ​​may be used with or without a corresponding sequence of instantaneous phase values ​​output by the Hilbert transform. Examples of techniques for identifying echo arrival times based on the phase and envelope output of the Hilbert transform may be found in Mario Kupnik, Edwin Krasser, and Martin The invention is found in "Absolute Transit Time Detection for Ultrasonic Gas Flowmeters Based on Time and Phase Domain Characteristics" by IEEE, Proceedings of the 2007 IEEE Ultrasonic Symposium, New York, NY, 2007, pp. 142-145. However, those skilled in the art will recognize that there are many techniques for determining the arrival time of an echo using the Hilbert transform, any of which may be used without departing from the scope of this invention.

[0305] In some embodiments of method 31000, the time offset is determined by transforming the baseline and signal waveforms into a cross-correlation signal and calculating the time offset based on the cross-correlation signal. In these embodiments, block 31012 can exclude blocks 31014, 31016, and 31018 because the peak of the cross-correlation signal will directly indicate the time offset Δt without separately determining the signal and baseline arrival times. Those skilled in the art will recognize that there are many techniques for determining the time offset using cross-correlation, and any of them can be used without departing from the scope of this document.

[0306] Fig.1331 is a flow chart of a method 31200 for processing a waveform to identify an arrival time of an echo. As with method 31100, method 31200 may be performed using a signal waveform to identify a signal arrival time, in which case method 31200 may replace block 31014 of method 31000. Similarly, method 31200 may be performed using a baseline waveform to identify a baseline arrival time, in which case method 31200 may replace block 31016 of method 31000. Method 31200 is similar to method 31100 except that the arrival time is determined from the extreme values ​​(i.e., maximum or minimum values) of the sub-waveforms. To make the following discussion clearer, the maximum value is used for the extreme value. However, the minimum value may be used instead without departing from the scope of this document.

[0307] In block 31202 of method 31200, the waveform is processed to identify a maximum of the echo. In block 31204, the time of arrival of the echo is calculated based on the time of the maximum. Blocks 31202 and 31204 may be performed using the signal waveform to calculate the signal arrival time. Similarly, blocks 31202 and 31204 may be performed using the baseline waveform to calculate the baseline arrival time The baseline arrival time can be determined Determine signal arrival time before or after

[0308] Some embodiments of method 31200 include block 31102, wherein a sub-waveform of an echo is selected from the waveform. In these embodiments, blocks 31202 and 31204 are performed using this sub-waveform. The amplitude thus obtained can be a local maximum of the sub-waveform. Some embodiments of method 31200 include block 31106, wherein the sub-waveform is interpolated to obtain a best fit curve. In these embodiments, blocks 31202 and 31204 are performed using the best fit curve. The entire sub-waveform can be interpolated, or a portion thereof can be interpolated.

[0309] like Figure 6 As shown, sub-waveform 3504 lasts for several cycles, thereby forming a sequence of extrema. Any one or more of these extrema can be used to determine the signal arrival time of the echo. The sequence of extrema can include only maximum values, only minimum values, or both. In some embodiments, the sequence of signal extrema is processed to determine the signal arrival time, and the sequence of baseline extrema is similarly processed to determine the baseline arrival time. Similar processing of these two sequences ensures that the definition of arrival time is the same for the baseline and signal echo. For example, in the case where only one baseline maximum is used to determine the baseline arrival time And only one signal maximum is used to determine the signal arrival time In an embodiment of the present invention, the position of the baseline maximum value in the baseline extreme value sequence may be the same as the position of the signal maximum value in the signal extreme value sequence.

[0310] Fig.14 A method 31300 of processing a signal and a baseline waveform to identify a time offset Δt is illustrated. Similar to cross-correlation, the method 31300 combines the signal waveform and the baseline waveform to directly determine Δt, rather than processing the signal waveform and the baseline waveform separately to determine and Thus, method 31300 may be used in block 31012 of method 31000. Method 31300 is based on exciting pixel elements using several consecutive cycles of a single frequency waveform (also referred to as a "tone burst"). For example, a tone burst may be formed by eight consecutive cycles of a sine wave having a frequency of 150 MHz. The tone burst may be unipolar, or may be bipolar. In addition, the tone burst may be low pass filtered to smooth its envelope. It may be assumed that the echoes generated from the tone burst have the same fixed number of consecutive cycles of the center frequency. Specifically, any time offset Δt generated from the object is constant throughout the echo. In this case, the signal sub-waveform 31304 may be subtracted from the baseline sub-waveform 31302 to obtain a differential waveform 31306. The frequency of the differential waveform 31306 is the same as the frequencies of the sub-waveforms 31302 and 31304, and the amplitude of the differential waveform 31306 depends on the time offset Δt. Therefore, the differential waveform 31306 may be processed to determine the time offset Δt.

[0311] For small values ​​of time offset Δt, the amplitude of the differential waveform 31306 will be smaller than the amplitudes of the sub-waveforms 31302 and 31304. In this case, the SNR of the differential waveform 31306 will be lower than the sub-waveforms 31302 and 31304. This reduced SNR may limit how well the time offset Δt can be determined. One way to maintain the SNR is to fit each of the sub-waveforms 31302 and 31304 to a sine wave with variable phase and amplitude (but fixed frequency), and then calculate the differential waveform 31306 from the best fit sine wave. Other techniques may be used to maintain the SNR without departing from the scope of this document.

[0312] Fig.15Two sampling methods 31402 and 31404 are illustrated for processing waveforms to identify the arrival time of an echo. In method 31402, the system 10 samples an echo including a sinusoidal waveform at a sampling rate of 10 samples per cycle of the sinusoidal wave. The system 10 can analyze the collected 10 samples per cycle to create an estimate of the echo (e.g., an estimate of the amplitude and / or phase). In method 31404, the echo (e.g., the same echo as in method 31402) is sampled at a rate of 2 samples per cycle of the sinusoidal wave. The system 10 can similarly provide an estimate of the echo (e.g., an estimate of the amplitude and / or phase) after knowing the parameters of the transmitted signal on which the echo is based. The reduced sampling of method 31402 provides many advantages, such as processing speed, data storage and transmission, and other advantages. Similar to methods 31100 and 31200, methods 31402 and / or 31404 can be performed using a signal waveform to calculate the signal arrival time In this case, methods 31402 and / or 31404 may be used in block 31014 of method 31000. Similarly, methods 31402 and / or 31404 may be performed using a baseline waveform to calculate a baseline arrival time. In this case, methods 31402 and / or 31404 may be used in block 31016 of method 31000. In determining the baseline arrival time Determine signal arrival time before or after

[0313] Methods 31402 and / or 31404 may implement orthogonal sampling of the sensed echoes, which advantageously reduces the amount of data to be recorded and processed compared to uniform sampling. For example, Figure 7 The sub-waveforms 3602, 3604 in FIG. 3 may be uniformly sampled (e.g., by Figure 8 ADC3706). At this sampling rate, for the center frequency f 0 For a 150MHz waveform, approximately eight data points can be sampled per cycle. However, due to the center frequency f 0 It is known that, therefore, only two data points need to be sampled per cycle to determine the phase. These two data points must be separated in time by a quarter of a cycle (i.e., in quadrature), but can occur anywhere within a single cycle. Specifically, consider the first and second quadrature data points (t 1 ,a 1 ) and (t 2 ,a 2 ). These two data points constrain the baseline waveform to the mathematical form y(t) = A cos cos(2πf0 t+φ b ) of the sine wave, where And the baseline phase φ b By solving a 1 =A cos cos(2πf 0 t 1 +φ b ) or a 2 =Acos cos(2πf 0 t 2 +φ b ). Repeat this process for two orthogonal data points from the signal waveform to obtain the signal phase φ s The resulting time offset is then Δt = (φ s -φ b ) / (2πf 0 ), where φ s and φ b The unit is radians, and f 0 The unit is Hertz. Or, the phase shift φ s -φ b can be used directly to create a time-shifted image (e.g., by mapping phase shifts to corresponding grayscale values ​​of pixels of the time-shifted image).

[0314] Example pseudo code

[0315] The following pseudo code is an exemplary implementation of method 31000, where method 31200 is used for each of blocks 31014 and 31016. Comments are preceded by a "#" symbol.

[0316] #Define constants

[0317] n_tx=250#Number of transmitting electrodes

[0318] n_rx=250#Number of sensing electrodes

[0319] wfm_size = 100 # The number of data points in each waveform

[0320] interp_factor=25#interpolation factor

[0321] fc = 150MHz #Center frequency of the transmitted pulse and sensed echo

[0322] fs=1.25GSPS #ADC sampling rate

[0323] Ts = fs x interp_factor # sampling period after interpolation

[0324] # Retrieve a three-dimensional (3D) array of the baseline waveform. The first index of the array # runs from 1 to n_tx and # identifies a corresponding row of the sensor. The second index of the array runs from 1 to n_rx and # identifies a corresponding column of the sensor. The third index runs from 1 to wfm_size and # identifies a data point for each waveform.

[0325] input_data_baseline=echo_array_baseline(n_tx,n_rx,wfm_size)

[0326] # Get a 3D matrix-like representation of the signal waveform

[0327] input_data_signal=echo_array_signal(n_tx,n_rx,wfm_size)

[0328] #Preprocess each waveform to remove the mean. Parameter "3" indicates which dimension of the #3D array corresponds to the time of the waveform.

[0329] input_data_baseline=mean_removal(input_data_baseline,3)

[0330] input_data_signal=mean_removal(input_data_signal,3)

[0331] #Interpolate each waveform so that sampling period << expected time delay

[0332] input_data_baseline=interpolation(input_data_baseline,interp_factor)

[0333] input_data_signal=interpolation(input_data_signal, interp_factor) #Bandpass filter each waveform between 120 and 180 MHz. Parameter BW is the bandwidth, # and parameter N_order is the filter order.

[0334] Input_data_baseline=FIR_filter(input_data_baseline,BW=[120 180]MHz,N_order=100)

[0335] Input_data_signal=FIR_filter(input_data_signal,BW=[120 180]MHz,N_order=100)

[0336] #Process each waveform peak to identify when the waveform reaches its peak

[0337] [max_val_baseline,max_idx_baseline]=max(input_data_baseline(sub_window),3)

[0338] [max_val_signal,max_idx_signal]=max(input_data_signal(sub_window),3)

[0339] #Generate a 2D time-shifted map. #Multiply each pixel of the map by 1e12

[0340] #To express the result in picoseconds

[0341] Raw_image=(max_idx_signal-max_idx_baseline)x Ts x 1e12

[0342] Embodiment with a single ultrasonic transducer

[0343] As described above, method 31000 may be performed using a single ultrasonic transducer (e.g., not part of an array of multiple transducers). In this case, method 31000 may be used to detect the presence of an object in contact with a platen surface of a platen. For example, the object may be a contact Figures 2 to 5 Human tissue, such as a finger 3130, can be detected by measuring the time offset of the top surface 3112 of the pressure plate 3102. The presence of an object can be determined by the time offset, for example, by comparing the time offset to a threshold. If the time offset is less than the threshold, the time offset can be considered to be zero, so the signal and baseline arrival times are the same. In this case, it can be inferred that no object is contacting the pressure plate. On the other hand, if the time offset is greater than the threshold, it can be inferred that an object was contacting the pressure plate when the signal waveform was recorded. The threshold can be large enough to ensure that statistical fluctuations in the echo arrival times do not result in a false indication of the presence of an object. An indication of the presence of an object can then be output.

[0344] Embodiments with biometric sensing

[0345] Method 31000 may also be used for biometric sensing. For example, in some embodiments, the object is a finger and the time-shifted image is a fingerprint of the finger. Time-shifted image 3804 is an example of a time-shifted image of a fingerprint. Method 31000 may also include determining a contact area between the finger and the platen surface based on the time-shifted image. The contact area may be the area of ​​the ridges of the finger in contact with the platen surface (e.g., see Figure 4 and Figure 5 ridge 3316 of finger 3130 in the figure). Method 31000 may also include determining a force applied by a finger and / or other body tissue on the surface of the pressure plate based on the contact area. Method 31000 may also include: (i) repeating the determining of the time offset (i.e., block 31012) and the determining of the contact area to generate a time series of the contact area; (ii) determining an oscillation period of the time series of the contact area; and (iii) calculating a pulse rate based on the oscillation period. Further details on using a two-dimensional ultrasonic transducer array to measure the contact area of ​​a finger and thereby determine the pulse rate are described by Gerard Touma in "A row-column addressed acoustic biometric scanner integrated with pulse oximetry" (Stanford University Ph.D. dissertation, 2020). The reference also describes how to combine an at least partially transparent ultrasonic transducer array with a pulse oximeter.

[0346] Example without baseline waveform

[0347] Fig.16 31500 for generating a time-shifted image in the absence of a baseline waveform. In block 31502, a time offset between (i) an arrival time of an echo sensed by a pixel element of an ultrasound transducer array and (ii) a baseline arrival time is determined. Any technique or method described herein for determining an echo arrival time may be used as part of block 31502. For example, method 31100 or method 31200 may be used to determine an arrival time based on a waveform recorded from a pixel element. In block 31504, method 31500 repeats block 31502 for each pixel element of the ultrasound transducer array. The echo may be generated by an object contacting a platen surface (e.g., Figures 2 to 5 The object may be a finger (eg, finger 3130) and / or other human tissue.

[0348] In block 31510, a time-shifted image is generated based on the time shift determined for the pixel elements. Similar to method 31000, the pixels of the time-shifted image may have a one-to-one correspondence with the pixel elements of the ultrasound transducer array. The time-shifted image may then be output. When the object contacting the platen is a finger, the time-shifted image may be a fingerprint of the finger.

[0349] Unlike the 31000 method, in which the baseline arrival time is determined individually for each pixel element, in the 31500 method, the baseline arrival time is the same for all pixel elements. The baseline arrival time can be calculated based on the arrival time of one or more pixel elements. For example, the baseline arrival time can be set equal to the arrival time of one of the pixel elements. Alternatively, the baseline arrival time can be set to the average of the arrival times of all pixel elements. The baseline arrival time can also be set to zero.

[0350] The foregoing embodiments of method 31500 may be implemented on a computer system (e.g., see Fig.19 The ultrasonic signal processing system 31800 is executed on the computer system, which receives the ultrasonic signal from the sensor system (e.g., Figure 8 A third party may operate the sensor system and send the recorded waveforms to a computer system that processes the waveforms to determine the echo arrival times. Thus, an ultrasonic transducer array is not required to perform method 31500. However, in some embodiments, method 31500 includes blocks 31002, 31004, and 31006, in which the ultrasonic transducer array is operated to record a waveform for each pixel element. These waveforms may then be used by block 31502 to determine the corresponding echo arrival times.

[0351] Object Detection Methods

[0352] Fig.17 is a flow chart of a method 31600 for object detection without using a baseline waveform. In block 31602, an arrival time is determined for an echo sensed by a pixel element of an ultrasound transducer array. Any technique or method for determining an echo arrival time (e.g., method 31100 or method 31200) may be used as part of block 31602. In block 31604, method 31600 repeats block 31602 for each pixel element of the ultrasound transducer array. The echo is generated from a platen surface where an object contacts the platen. The object may be human tissue, such as a finger (e.g., Figures 2 to 5 3102).

[0353] The method 31600 also includes a block 31606, wherein a deviation is calculated based on the arrival time determined for one or more pixel elements (e.g., for each pixel element). The deviation is also referred to as an "arrival time deviation". The method 31600 also includes a block 31608, wherein the presence of an object is determined based on the arrival time deviation. The arrival time deviation can be a standard deviation, a variance, a median absolute deviation, and / or any other statistical measure of dispersion. In some embodiments, the method 31600 includes a block 31610, wherein the arrival time deviation is compared to a threshold. For example, if the arrival time deviation is less than the threshold, it can be inferred that no object is contacting the pressure plate surface. However, if the arrival time deviation is greater than the threshold, it can be inferred that an object is contacting the pressure plate surface. Specifically, the ridges 3316 and valleys 3318 of the fingers (e.g., fingers and / or other body parts) can cause a significantly increased spread of the arrival times compared to the arrival time distribution without the fingers contacting the pressure plate surface.

[0354] In some embodiments, method 31600 includes block 31612, where an indication of the presence of an object is output. The indication may be binary (i.e., indicating that the object is present or not). Alternatively, the indication may be a value indicating a probability that the object is in contact with the platen surface. The value may be calculated based on the arrival time deviation, such that a higher arrival time deviation results in a higher output value, indicating a higher probability that the object is present on the platen.

[0355] The foregoing embodiments of method 31600 may be performed on a computer system (e.g., see Fig.19 The ultrasonic signal processing system 31800 is executed on the computer system, which receives the ultrasonic signal from the sensor system (e.g., Figure 8 In some embodiments, the method 31600 includes blocks 31002, 31004, and 31006, in which the ultrasonic transducer array is operated to record a waveform for each pixel element. These waveforms can then be used by block 31602 to determine the corresponding echo arrival times.

[0356] Fig.18is a flow chart of object detection method 31700, which is similar to method 31600, except that a baseline waveform is used. Thus, method 31700 implements baseline time compensation by using a time offset for each pixel element rather than a single echo arrival time. Thus, method 31700 includes blocks 31012 and 31020 of method 31000. Method 31700 also includes: block 31406, in which a deviation is calculated based on the time offset; and block 31408, in which the presence of an object is determined based on the deviation (e.g., by comparing with a threshold). This deviation is also referred to as a "time offset deviation." Similar to method 31600, in method 31700, a signal echo can be generated from the surface of a platen where an object contacts the platen. The object can be human tissue, such as a finger (e.g., Figures 2 to 5 The method 31700 may also include a block 31412, wherein an indication of the presence of the object is output.

[0357] Compared to method 31600, method 31700 can advantageously improve the accuracy of determining the presence of an object, particularly when the deviation of the round-trip propagation time on the platen is comparable to or greater than the arrival time deviation. When no object is contacting the platen, each time offset is close to zero, and the resulting time offset deviation may be less than the arrival time deviation. When an object is contacting the platen, the time offsets of some pixel elements will no longer be close to zero. As a result, the time offset deviation may increase significantly, particularly for fingerprints, whose ridges and valleys typically produce a wide dispersion of time offsets. This increase in time offset deviation may be significantly greater than the increase in arrival time deviation, thereby advantageously helping to distinguish between situations where no object is contacting the platen and situations where an object is contacting the platen.

[0358] The foregoing embodiments of method 31700 may be implemented on a computer system (e.g., see Fig.19 The ultrasonic signal processing system 31800 is executed on the computer system, which receives the ultrasonic signal from the sensor system (e.g., Figure 8 A third party may operate the sensor system and send the recorded waveform to a computer system that processes the waveform to determine the signal and baseline arrival times. Thus, an ultrasonic transducer array is not required to perform method 31700. However, in some embodiments, method 31700 includes blocks 31002, 31004, and 31006, in which the ultrasonic transducer array is operated to record waveforms for each pixel element. In some of these embodiments, method 31700 repeats blocks 31002, 31004, and 31006 twice, the first time to obtain a signal waveform and the second time to obtain a baseline waveform. Block 31012 may then use these signal waveforms and baseline waveforms to determine the time delay.

[0359] System Example

[0360] Fig.19 31800 is a block diagram of an ultrasound signal processing system 31800, which may be used to implement the present method embodiment. The ultrasound signal processing system 31800 is a computer system that may form at least a portion of an ultrasound-based sensor system, such as Figure 8 The finger sensor system 3700 in FIG. 31800. For example, the ultrasonic signal processing system 31800 can be used as one or both of the computer 3710 and the real-time processor 3708.

[0361] The ultrasound signal processing system 31800 includes a processor 31802 and a memory 31806, which communicate with each other via a system bus 31804. The system 31800 may also include at least one I / O block 31812 for communicating with at least one peripheral device. Fig.19 The system 31800 is shown with only one I / O block 31812, but the system 31800 may include any number of I / O blocks 31812 as needed to implement the functionality described herein. For example, when the system 31800 is used as a computer 3710, the I / O block 31812 may be used to receive the waveform 3500 from the real-time processor 3708. In this case, the I / O block 31812 may be a serial port or parallel port that interfaces with the real-time processor 3708. Similarly, the I / O block 31812 may be a graphics card for outputting a time-shifted image to a display screen, such as the display screen 31803 (e.g., similar to the display screen 31803). Figure 8 The I / O block 31812 may be a display screen of the display screen 3712 of the system 31800, or a host adapter that connects the system 31800 to a storage device (e.g., a hard drive, a solid-state drive, a memory card, a memory stick, etc.) to store and retrieve time-shifted images and other data. The I / O block 31812 may also be a host adapter that connects the system 31800 to a network to communicate with other devices or computer systems (e.g., via a wide area network, a local area network, the Internet, Wi-Fi, USB, etc.), such as a biometric security system that processes the time-shifted images to determine access rights to a room, a computer system, a file, etc. In some embodiments, the system 31800 implements at least some of the functionality of a biometric security system. Therefore, the system 31800 is not limited to implementing only the functionality of the finger sensor system 3700.

[0362] Processor 31802 may be any type of circuit capable of performing logic, control, and input / output operations, for example, processor 31802 may include one or more of a microprocessor having one or more central processing unit (CPU) cores, a graphics processing unit (GPU), a digital signal processor (DSP), an FPGA, a system-on-chip (SoC), and a microcontroller unit (MCU). Processor 31802 may also include a memory controller, a bus controller, one or more coprocessors, and / or other components that manage the flow of data between processor 31802 and other devices communicatively coupled to system bus 31804. In an embodiment where system 31800 implements the functionality of real-time processor 3708, processor 31802 includes at least one circuit and / or chip (e.g., an integrated circuit) that operates deterministically as described above. Processor 31802 may be Figure 8 An example of a processor 3720.

[0363] The memory 31806 stores machine-readable instructions 31820, which, when executed by the processor 31802, control the control system 31800 to implement the functions and methods described herein (e.g., one or more of the methods 31000 to 31700). The memory 31806 also stores data 31840 used by the processor 31802 when executing the machine-readable instructions 31820. Fig.19 In the example of , the machine readable instructions 31820 include a time offset determiner 31822 that determines a time offset 31846 between a signal arrival time of a signal echo sensed by the ultrasound transducer and a baseline arrival time of a baseline echo sensed by the ultrasound transducer. In this case, the time offset determiner 31822 implements block 31012 of method 31000. The memory 31806 may store a comparison Fig.19 More machine readable instructions 31820 may be shown without departing from the scope of this document. Similarly, memory 31806 may store more than Fig.19 More data 31840 may be shown without departing from the scope of this document. Memory 31806 may be Figure 8 An example of memory 3722 of.

[0364] In some embodiments, the time offset determiner 31822 implements block 31010 of method 31000 by identifying a signal echo from a signal waveform 31842 obtained from an ultrasonic transducer when an object is contacting a platen surface of the platen. Similarly, the time offset determiner 31822 implements block 31008 of method 31000 by identifying a baseline echo from a baseline waveform 31844 obtained from an ultrasonic transducer when an object is not contacting a platen surface. The time offset determiner 31822 may also implement block 31014 of method 31000 by processing the signal waveform 31842 to identify a signal arrival time 31850 of the signal echo, implement block 31016 of method 31000 by processing the baseline waveform 31844 to identify a baseline arrival time 31852 of the baseline echo, and implement block 31018 of method 31000 by subtracting the baseline arrival time 31852 from the signal arrival time 31850 to obtain the time offset 31846. Each of the waveforms 31842 and 31844 is Figure 6 The waveform 3500W is an example, and the time offset 31846 is an example of the time offset Δt (see Figure 7 ), signal arrival time 31850 is the signal arrival time , and the baseline arrival time 31852 is the baseline arrival time .

[0365] The machine-readable instructions 31820 may also include an image generator 31824 that determines the time offset of each pixel for one or more pixel elements (e.g., all pixel elements) of the ultrasound transducer array to generate an array of time offsets. The image generator 31824 may then generate a time-shifted image 31848 based on the time-shifted array. Thus, the image generator 31824 may implement blocks 31020 and 31022 of the method 31000. Although in Fig. 9 31806 may store additional machine-readable instructions 31820 for controlling the system 31800 to output the time-shifted image 31848 (e.g., to a peripheral device or another computer system via the I / O block 31812). The machine-readable instructions 31820 may include a transducer controller 31828 as shown, wherein the transducer controller 31828 includes data providing instructions for the timing of energy delivery and recording of reflected energy (echoes) for each pixel element.

[0366] In some embodiments, system 31800 includes ADC 31808 that digitizes amplified output 3404. Fig.19As shown, ADC 31808 can be connected to bus 31804 so that sensor data 3716 output by ADC 31808 is stored in memory 31806. Alternatively, sensor data 3716 can be directly transmitted to processor 31802 via bus 31804 for time stamp processing, thereby converting sensor data 3716 into a waveform. ADC 31808 is Figure 8 An example of ADC 3706.

[0367] In some embodiments, system 31800 includes a MUX controller 31810 that outputs one or more digital control lines 31814 to drive MUX 3702. Fig.19 As shown, the MUX controller 31810 can be connected to the bus 31804 so that the digital control line 31814 can be controlled by the processor 31802. However, the MUX controller 31810 can also be embedded within the processor 31802. In embodiments where the system 31800 implements real-time functions (e.g., timestamp processing, MUX control, ADC sampling, etc.), the system 31800 can also include a time base 3728.

[0368] Fig.19 The system 31800 is shown as a computing device employing a von-Neumann architecture, but in some embodiments, the system 31800 uses a Harvard architecture or a modified Harvard architecture. In these embodiments, the machine-readable instructions 31820 may be stored as firmware in a memory (e.g., non-volatile flash memory) separate from the data 31840. Thus, the system 31800 may form part of an embedded system that includes one or more of the sensor array 3100, the MUX 3702, the amplifier 3402, and the signal source 3304.

[0369] The system of the present invention can generate images (e.g., images of fingerprints or other tissue surfaces) using amplitude-shifted image creation or time-shifted image creation as described herein. In some embodiments, the system 10 is configured to use both amplitude-shifted image creation and time-shifted image creation (e.g., to create enhanced images of fingerprints or other tissue surfaces). In these embodiments, the system 10 can be configured to utilize beamforming (also described herein) to further enhance the image quality achieved.

[0370] Overall Figures 20 to 28 , illustrates various configurations of sensors 100 and systems 10, such as ultrasound-based systems and sensors utilizing a multi-platen configuration.

[0371] In some embodiments, the sensor 100 is constructed and arranged as described herein with reference to Figures 25A-25D described.

[0372] Embodiments of the present invention may include multi-platen ultrasonic sensors (e.g., fingerprint sensors) utilizing two or more platens. These sensors may be used to sense one or more fingerprints. Advantageously, embodiments of the present invention may simultaneously drive and sense multiple pixel transducers, thereby reducing the time required to scan a group of multiple pixel transducers and generate a fingerprint image. For example, the time required to operate a group of multiple pixel transducers of a multi-platen sensor having two platens may be approximately half the time required to operate each pixel transducer of the group individually. Signals from electrically paired pixel transducers (e.g., an electrically connected group of two, three, or more pixel transducers) may be distinguished and assigned to a platen using time discrimination, frequency discrimination, or a combination thereof. In addition, some embodiments of the present invention are also characterized by electrically paired pixel transducers that share a transmitting electrode and a receiving electrode. In some embodiments, the multi-platen ultrasonic sensor contemplated by the present invention includes three, four, five, or more platens.

[0373] Advantageously, electrically paired pixel transducers reduce the number of electrical connections to the fingerprint and / or other sensors (herein referred to as "sensors" or "fingerprint sensors"), thereby simplifying the multiplexing circuits that interface with the sensors. Another advantage of embodiments of the present invention is that the energy per scan is reduced. A portion of the energy consumed by an ultrasonic fingerprint sensor system is proportional to the scan time. This energy is typically consumed by amplifiers and other electronic devices that are maintained in an "active" state during the scan. Because embodiments of the present invention shorten the scan time, these electronic devices can spend more time in a low-energy "sleep" state. Reducing the energy per scan can extend battery life, for example when embodiments of the present invention are used in portable electronic devices (e.g., smart phones, laptops, and tablet devices), in which extended battery life is a significant advantage.

[0374] Another advantage of embodiments of the present invention is that they can tolerate variations in platen topography that typically occur during manufacturing. For example, when the platen is a glass display screen for a smartphone, tablet device, or similar product, the resulting platen topography may generally depend on the specific process used to manufacture the display screen, the size of each display pixel, the overall size of the display screen, and / or other factors. In any case, the pixel elements can be deposited on the rear end face of the platen while still achieving all or at least a portion of the benefits described above. Thus, while embodiments of the present invention are shown as having a platen with a completely flat surface, it should be understood that the platen surface may have some curvature, surface variations, depressions, defects, and / or other topological features (e.g., topological inhomogeneities), and the presence of these topological features will have little, if any, effect on the manufacture and / or operation (e.g., performance) of embodiments of the present invention.

[0375] Although embodiments of the present invention are described as fingerprint sensors, embodiments of the present invention can be used to measure any object in contact with two, three, or more pressure plates, provided that the presence of the object causes a measurable shift in the amplitude and / or phase of the echo. Examples of such objects include prosthetic limbs, toes, and other human tissue, as well as inanimate objects. Thus, embodiments of the present invention can be used to determine the binary presence of a single object contacting any one of the pressure plates, or the binary presence of an integer number of objects contacting the pressure plates (e.g., multiple fingers from one or more users). This ability to detect the presence of objects can be combined with fingerprint sensing. For example, embodiments of the present invention can be programmed to perform fingerprint sensing only after one or more objects are detected contacting the pressure plates (e.g., pressure plates 4102 and 4103 described herein).

[0376] When used for fingerprint sensing, embodiments of the present invention can be combined with other physical, physiological, and biological measurements as part of a multifunctional biometric system. For example, documents (i) International Publication No. WO 2019 / 032590, entitled "Interactive Biometric Touch Scanner," and (ii) Gerard Touma, "A row-column addressed acoustic biometric scanner integrated with pulse oximetry" (Stanford University Ph.D. dissertation, 2020) show how pulse oximetry can be combined with an ultrasonic transducer array when at least a portion of the transducer array is optically transparent (e.g., in the near infrared). Each of these documents is hereby incorporated by reference in its entirety for all purposes.

[0377] As another example of a biometric measurement, embodiments of the present invention may be used to determine the contact area between a finger ridge and one of the pressure plates. This contact area may be measured over time to identify periodic changes in the indicator pulse. In this way, the biometric system can distinguish between living tissue and inanimate matter. Embodiments of the present invention may be combined with other sensors and / or biometric functions without departing from the scope of this document. In addition, multiple biometric functions may be implemented using different pressure plates of a fingerprint sensor. For example, one pressure plate may be used for pulse oximetry of a finger, while another pressure plate is used to measure the pulse and / or other physiological parameters of one or more users (referred to herein as "users").

[0378] Fig. 20 is a perspective view of a multi-platen ultrasonic fingerprint sensor 4100 having a first platen 4102 and a second platen 4103 with different round trip propagation times. Fig.21 yes Fig. 20FIG. 4 is a side cross-sectional view of a multi-platen ultrasonic fingerprint sensor 4100. The fingerprint sensor 4100 also includes a first ultrasonic transducer array 4104, which may be bonded to and / or fabricated on a first rear end face 4122 of the first platen 4102. The ultrasonic pulse emitted by the first ultrasonic transducer array 4104 propagates along the +z direction (see the right-hand coordinate system 4120) through the first platen 4102 toward the first front end face 4112 of the first platen 4102. The first front end face 4112 is a boundary between materials with different mechanical impedances (e.g., different densities and / or stiffnesses). Therefore, the ultrasonic pulse will be reflected from the first front end face 4112, and the resulting reflection will propagate along the -z direction through the first platen 4102 toward the first rear end face 4122, where it is detected by the first ultrasonic transducer array 4104. This reflection is also called an echo.

[0379] Similarly, the multi-platen ultrasonic fingerprint sensor 4100 further includes a second ultrasonic transducer array 4105, which may be bonded to the second rear end face 4123 of the second platen 4103 and / or fabricated on the second rear end face 4122 of the second platen 4102. The ultrasonic pulse emitted by the second ultrasonic transducer array 4105 propagates along the +z direction through the second platen 4103 toward the second front end 4113 of the second platen 4103. Like the first front end face 4112, the second front end face 4113 is a boundary between materials with different mechanical impedances, so the ultrasonic pulse is reflected from the second front end face 4113. The resulting reflection or echo propagates along the -z direction through the second platen 4103 toward the second rear end face 4123, where it is detected by the second ultrasonic transducer array 4105. In some embodiments, the end surfaces 4112 and 4113 can be distinguished (e.g., tactically distinguished) by a user's fingers so that the user can place one or more fingers on a particular surface via the distinction (e.g., select one surface rather than another to perform a particular function associated with one surface rather than the other).

[0380] exist Fig. 20 and Fig.21 In the embodiment, the first pressing plate 4102 and the second pressing plate 4103 have different round trip propagation times due to different thicknesses. Specifically, the first pressing plate 4102 has a first thickness d along the z direction. 1 , and the second pressing plate 4103 has a thickness d 1 Different second thickness d 2 The first thickness d 1 is measured between the first rear end face 4122 and the first front end face 4112. Similarly, the second thickness d 2is measured between the second rear end face 4123 and the second front end face 4113. Fig. 20 and Fig.21 Display the first thickness d 1 Greater than the second thickness d 2 , but the first thickness d 1 It can also be smaller than the second thickness d 2 As described in more detail below, in some embodiments of the present invention, the first thickness d 1 With the second thickness d 2 same.

[0381] A finger or other body tissue (shown as finger 4130) is physically contacted with front faces 4112 and 4113 to, for example, detect a fingerprint. Fig. 20 and Fig.21 The sensor 4100 is shown to be configured to sense the fingerprint of only one finger 4130, but the sensor 4100 may alternatively be configured to sense more than one finger simultaneously (e.g., from a single user or from multiple users). For example, a first finger 4130(1) may be in physical contact with the first front face 4112, while a second finger 4130(2) is in physical contact with the second front face 4113 (e.g., see FIG. 4 ). Fig. 22 and Fig.23 ). In order to detect a complete fingerprint, each of the pressure plates 4102 and 4103 may have a thickness of at least 0.1 cm 2 、0.3cm 2 , 0.5cm 2 、0.7cm 2 and / or 1cm 2 For clarity, Fig. 20 and Fig.21 Finger 4130 is not drawn to scale.

[0382] The first ultrasound transducer array 4104 has a plurality of first pixel transducers 4110. Fig. 20 and Fig.21 In the example of , these first pixel transducers are arranged in a linear two-dimensional array of rows and columns. Similarly, the second ultrasound transducer array 4104 has a plurality of second pixel transducers 4111, which are also shown to be arranged in a linear two-dimensional array. Fig. 20 and Fig.21, the first pixel transducer 4110 can be addressed in rows and columns via a plurality of receiving electrodes 4108 and a plurality of first transmitting electrodes 4106. Similarly, the second pixel transducer 4111 can be addressed in rows and columns via a plurality of receiving electrodes 4108 and a plurality of second transmitting electrodes 4107. Thus, each first transmitting electrode 4106 extends only through the first platen 4102 in the y direction, each second transmitting electrode 4107 extends only through the second platen 4103 in the y direction, and each receiving electrode 4108 extends through both the first platen 4102 and the second platen 4103 in the x direction.

[0383] The first ultrasound transducer array 4104 also includes a first piezoelectric layer 4114 located between the receiving electrode 4108 and the first transmitting electrode 4106. Similarly, the second ultrasound transducer array 4105 includes a second piezoelectric layer 4115 located between the receiving electrode 4108 and the second transmitting electrode 4107. Thus, each first pixel transducer 4110(j,i) is spatially defined by the overlap of the jth receiving electrode 4108(j) and the i-th first transmitting electrode 4106(i) in the xy plane, and each second pixel transducer 4111(j,i) is spatially defined by the overlap of the jth receiving electrode 4108(j) and the i-th second transmitting electrode 4107(i) in the xy plane.

[0384] For clarity, Fig. 20 Only nineteen first transmitting electrodes 4106, nineteen second transmitting electrodes 4107 and seventeen receiving electrodes 4108 are shown. Similarly, Fig.21 Only six first transmit electrodes 4106 and six second transmit electrodes 4107 are shown. However, the sensor 4100 may have any number of first transmit electrodes 4106, any number of second transmit electrodes 4107, and any number of receive electrodes 4108 without departing from the scope of this document. Typically, the fingerprint sensor 4100 will include hundreds of first transmit electrodes 4106, hundreds of second transmit electrodes 4107, and hundreds of receive electrodes 4108. For example, the first ultrasonic transducer array 4104 may have 512 first transmit electrodes 4106 and 512 receive electrodes 4108, corresponding to 512×512=262,144 first pixel transducers 4110. The second ultrasonic transducer array 4105 may be configured similarly, resulting in 524,288 pixel transducers 4110, 4111.

[0385] The first piezoelectric layer 4114 can be electrically driven (e.g., via ultrasound entering the first platen 4102). When the piezoelectric layer 4114 is mechanically driven by ultrasound, it generates a time-varying electrical signal that can be subsequently detected and processed. The first piezoelectric layer 4114 can be formed of a crystal (e.g., lithium niobate, lithium tantalate, quartz, etc.), a ceramic (e.g., zinc oxide, lead zirconate titanate, potassium niobate, barium titanate, etc.), a III-V or II-VI semiconductor (e.g., aluminum nitride, gallium arsenide, etc.), a polymer and / or any other piezoelectric material. Similar construction materials are also applicable to the second piezoelectric layer 4115.

[0386] Fig. 20 The i-th first transmit electrode 4106(i) is shown "transmitting" an ultrasound pulse 4116(i) into the first platen 4102 (i.e., the electrode-piezoelectric-electrode transducer element transmits an ultrasound pulse). Since each first transmit electrode 4106 extends the entire length of the first platen 4102 (in the y-direction), the ultrasound pulse 4116(i) similarly extends the entire length of the first platen 4102. Fig. 20 Similarly, the i-th second transmitting electrode 4107 ( i ) is shown transmitting an ultrasonic pulse 4117 ( i ) into the second pressure plate 4103 . Fig. 20 Also shown is a receive electrode 4108(j) transmitting an ultrasonic pulse 4118(j) into both platens 4102 and 4103. The receive electrode 4108(j) extends to the entire width (in the x-direction) of the fingerprint sensor 4100, and thus the ultrasonic pulse 4118(j) similarly extends to the entire width of both platens 4102 and 4103. Although electrodes 4106 and 4107 are referred to as "transmit" electrodes, it should be understood that these electrodes may alternatively or additionally be used to sense echoes. Similarly, electrode 4108, although referred to herein as a "receive" electrode, may alternatively or additionally be used to transmit ultrasonic pulses into platens 4102 and 4103.

[0387] Fig. 22 The multi-platen ultrasonic fingerprint sensor 4100 is shown being electrically driven to simultaneously transmit a first ultrasonic pulse 4316 into a first platen 4102 and a second ultrasonic pulse 4317 into a second platen 4103 . Fig.23 The fingerprint sensor 4100 is shown sensing a first echo 4416 generated when a first ultrasonic pulse 4316 is reflected from the first front face 4112 and a second echo 4417 generated when a second ultrasonic pulse 4317 is reflected from the second front face 4113 . Fig. 22 and Fig.23 is with Fig.21 Same cross-sectional view, but with the first finger 4130 ( 1 ) in contact with the first front face 4112 , and the second finger 4130 ( 2 ) in contact with the second front face 4113 . Fig. 22 and Fig.23 Best viewed in conjunction with the description below.

[0388] The bottom surface of each of the fingers 4130(1) and 4130(2) forms an alternating sequence of ridges 4320 (also referred to as "friction ridges" or "epidermal ridges") and valleys 4322. Each ridge 4320 of the first finger 4130(1) directly contacts the first front face 4112 of the first platen 4102, while the valleys 4322 do not directly contact the first front face 4112. Thus, below each valley 4322, air is in contact with the first front face 4112. Therefore, the reflection coefficient at the first front face 4112 is larger at the valleys 4322 and smaller at the ridges 4320, so that when reflection occurs at the ridges 4320 rather than at the valleys 4322, the amplitude of the echo 4416 is larger. Similar arguments apply to the second front face 4113.

[0389] exist Fig. 22 , the waveform generator 4304 outputs a drive signal 4306 to both the electrically connected first transmit electrode 4106(i) and the second transmit electrode 4107(i). All other transmit electrodes 4106 and 4107 are grounded, and all receive electrodes 4108 are grounded. In this configuration, the transmission time of the ultrasound pulses 4316 and 4317 is similar (ignoring the slight difference in electrical propagation time to the transmit electrodes 4106(i) and 4107(i)). Fig.23 In FIG. 4 , the receiving electrode 4108 (j) outputs a first electrical pulse 4418 in response to sensing the first echo 4416, and outputs a second electrical pulse 4420 in response to sensing the second echo 4417. Both electrical pulses 4418 and 4420 are output on the same electrical conductor and are processed by the amplifier 4402 into an amplified output 4404, which is subsequently digitized and processed. Fig.23 For the sensing shown, all transmitting electrodes 4106 and 4107 are grounded. Fig.23 Not shown, but all other receive electrodes 4108 are also grounded.

[0390] Since the platens 4102 and 4103 have different round trip propagation times, the electrical pulses 4418 and 4420 are distinguishable in time, that is, the electrical pulses 4418 and 4420 can be clearly assigned to the echoes 4416 and 4417. Specifically, the first round trip propagation time of the first platen 4102 is t 1 =2d 1 / v 1 , where v 1 is the speed of sound of the first platen 4102. Similarly, the second round trip propagation time of the second platen 4103 is t 2 =2d 2 / v2 , where v 2 is the speed of sound of the second platen 4103. Assume that the plates 4102 and 4103 are made of the same bulk material (i.e., v 1 =v 2 ), then select d 2 <d 1 means t 2 <t 1 . Therefore, a first electrical pulse 4418 is generated due to the second echo 4417, and a second electrical pulse 4420 is generated due to the first echo 4416.

[0391] Electrical pulses 4418 and 4420 may partially overlap (in time) while still being distinguishable in time. For example, the tail of first electrical pulse 4418 may overlap with the head of second electrical pulse 4420, such that the peaks of electrical pulses 4418 and 4420 are detected at different times. Thus, the delay between the peaks of electrical pulses 4418 and 4420 is |t 2 -t 1 |Can be smaller than the time width of electrical pulses 4418 and 4420.

[0392] In other embodiments, the pressure plates 4102 and 4103 are made of different materials so that v 1 ≠v 2 In these embodiments, the pressure plates 4102 and 4103 may have the same thickness, ie, d 1 =d 2 In this case, the pressing plates 4102 and 4103 can be placed on the corresponding sides so that the front end faces 4112 and 4113 are coplanar, and the rear end faces 4122 and 4123 are coplanar. In other embodiments, the pressing plates 4102 and 4103 are made of different materials and have different thicknesses.

[0393] In other embodiments, platens 4102 and 4103 form an array of ultrasonic waveguides rather than a bulk material. In these embodiments, one waveguide is located directly above each of pixel transducers 4110 and 4111. The velocity of the ultrasonic pulse (and the resulting echo) is determined by the dispersion equation of the waveguide, which generally depends on the geometry of the waveguide (e.g., lateral dimensions), the frequency, the speed of sound in the core of the waveguide, and the speed of sound in the material surrounding the core. Thus, the first platen 4102 may include a first array of waveguides sized to achieve a first velocity, while the second platen 4103 includes a second array of waveguides sized to achieve a second velocity different from the first velocity. In this case, platens 4102 and 4103 may have the same thickness, but different round-trip propagation times.

[0394] Each of the first pixel transducers 4110 is electrically paired with one of the second pixel transducers 4111. Specifically, the first pixel transducers 4110 and the second pixel transducers 4111 form a one-to-one correspondence. Here, "electrical pairing" means that the transmitting electrodes of the paired pixel transducers are directly electrically connected to each other, so they can be driven by a single waveform generator or oscillator. Similarly, "electrical pairing" also means that the receiving electrodes of the paired pixel transducers are directly electrically connected to each other, so their electrical outputs can be processed by a single amplifier and digitized by a single analog-to-digital (A / D) converter or channel.

[0395] Fig. 20 4109 is shown as being split into two "legs", one of which is routed to the first transmit electrode 4106(i) and the second to the second transmit electrode 4107(i). In this case, the two legs are electrically connected in parallel. In contrast, the receive electrode 4108(j) does not need to be split because it can be extended as a single line (straight, curved or sheet-like) across both platens 4102 and 4103. Although Fig. 20 For clarity, only a single conductor 4109 is shown, but it should be understood that each first transmit electrode 4106 is similarly connected to a corresponding second transmit electrode 4107. Fig. 20 The i-th first transmit electrode 4106(i) is shown paired with the i-th second transmit electrode 4107(i), but the pixel transducers 4110 and 4111 are not required to be paired in index order (eg, the 1st column electrode does not have to be paired with the 1st row electrode).

[0396] In other embodiments, the fingerprint sensor 4100 has individually addressable pixel transducers 4110 and 4111. In this case, each pixel transducer 4110 and 4111 has its own receiving electrode and transmitting electrode (i.e., not shared with other pixel transducers in the same row or column), and the above definition of "electrical pairing" still applies.

[0397] Fig.24 is a side cross-sectional view of a multi-platen ultrasonic fingerprint sensor 4500, which is Figure 20 to Figure 23 The multi-platen ultrasonic fingerprint sensor 4100 is similar to Fig.24 The front end faces 4112 and 4113 are coplanar. Figure 20 to Figure 23 In FIG. 4 , the rear faces 4122 and 4123 of the fingerprint sensor 4100 are coplanar, thereby creating a “step” (in the z direction) between the front faces 4112 and 4113. Fig.24In the fingerprint sensor 4500, this step appears between the rear end surfaces 4122 and 4123. Therefore, each receiving electrode 4108 changes its z position at the step to ensure electrical continuity between the two pressure plates 4102 and 4103.

[0398] The pressure plates 4102 and 4103 can be made of a block of material (e.g., glass or plastic) to form a single integral component. Alternatively, the pressure plates 4102 and 4103 can also be made separately and bonded along corresponding sides (e.g., via contact bonding, epoxy resin, anodic bonding with a silicon wafer in the middle, etc.). In some embodiments, the pressure plates 4102 and 4103 can be made using spin on glass (SOG) and / or etching processes. In other embodiments, the first pressure plate 4102 and the first transducer array 4104 are physically separated from the second pressure plate 4103 and the second transducer array 4105. In these embodiments, the first pixel transducer 4110 is electrically paired with the second pixel transducer 4111 (e.g., via a circuit board to which the transducer arrays 4104 and 4105 are soldered).

[0399] The above embodiments (for example, as referenced Figure 20 to Figure 23The electrical pulses 4418 and 4420 may be assigned to the first pixel transducer 4110 and the second pixel transducer 4111 using time discrimination of the electrical pulses 4418 and 4420. In other embodiments, the electrical pulses 4418 and 4420 have different frequencies, in which case the electrical pulses may be assigned to the pixel transducers 4110 and 4111 using frequency discrimination. For example, the first pixel transducer 4110 and the second pixel transducer 4111 may be made with different frequency responses. Specifically, the first pixel transducer 4110 may both have a first resonance with a first center frequency and a first bandwidth. Similarly, the second pixel transducer 4111 may both have a second resonance with a second center frequency different from the first center frequency, and a second bandwidth. The difference between the first and second center frequencies may be selected to be greater than the first and second bandwidths. In other embodiments, the first and second center frequencies are selected so that there is an overlap between the first and second bandwidths, and the electrical pulses 4418 and 4420 are distinguished using the frequency discrimination function as described above. The electrically paired pixel transducers 4110 and 4111 can be driven with a dual frequency waveform having a first component at a first center frequency and a second component at a second center frequency. Each of the first component and the second component can be a tone burst (i.e., an integer number of cycles of a single frequency sine waveform). The first component will resonantly excite the first pixel transducer 4110 (i) at the first center frequency, but not at the second center frequency. Conversely, the second component will resonantly excite the second pixel transducer 4111 (j) at the second center frequency, but not at the first center frequency. In this case, the ultrasonic pulses 4316 and 4317 will have different frequencies, which can be electronically resolved using signal processing techniques known in the art.

[0400] One advantage of frequency discrimination over time discrimination is that platens 4102 and 4103 can be of uniform thickness (ie, d 1 =d 2 ) of a single piece of material. However, in order to achieve a different frequency response, the first pixel transducer 4110 may need to be made separately from the second pixel transducer 4111. The frequency response can be modified via the thickness of the piezoelectric layer. For example, the first piezoelectric layer 4114 can be made to have a different thickness (in the z-direction) than the second piezoelectric layer 4115. Alternatively or additionally, the shape and thickness of the electrodes 4106, 4107, and 4108 can be modified to change the frequency response.

[0401] Embodiments of the present invention may be used to detect fingerprints or other imageable tissues or other patterns ("fingerprints" herein) by measuring amplitude offsets, for example, by measuring spatial variations in the amplitude of an echo. Alternatively, or in combination with amplitude offset measurements, embodiments of the present invention may be used to detect fingerprints by measuring time and / or phase offsets, for example, by measuring spatial variations in delay time, phase offset, or both. In some embodiments, beamforming techniques may be used to construct an image, for example while using amplitude offset measurements, phase offset measurements, or both. Further details on fingerprint detection using time and / or phase offsets are described in U.S. Provisional Patent Application No. 63 / 140,647, entitled "Ultrasound Signal-Processing System and Associated Methods," filed on January 22, 2021. This provisional patent application is hereby incorporated by reference in its entirety for all purposes.

[0402] Fig.25 4 is a side cross-sectional view of a multi-platen ultrasonic fingerprint sensor 4600 in which one pixel transducer array is used with both a first platen 4102 and a second platen 4103. Fingerprint sensor 4600 is also referred to as a "dual-sided" fingerprint sensor because it can simultaneously detect fingerprints from a first finger 4130(1) and a second finger 4130(2) where the plates are arranged in a back-to-back geometry (rather than a Figure 20 to Figure 24 ). When the pressure plates 4102 and 4103 are made of the same bulk material, the fingerprint sensor 4600 uses time discrimination to identify the electrical pulses on the pressure plates, so d 1 ≠d 2 Given the back-to-back geometry, fingerprint sensor 4600 is particularly advantageous when one of fingers 4130(1) and / or 4130(2) is a thumb. Alternatively, fingerprint sensor 4600 can be used to detect a fingerprint from each of two hands of a single person (e.g., finger 4130(1) is from the person's left hand and finger 4130(2) is from the person's right hand), and / or when one finger is from one person and the other finger is from another person.

[0403] Although Figure 20 to Figure 24Shown are multi-platen ultrasonic fingerprint sensors 4100 and 4500 with two platens 4102 and 4103, but the concepts of time discrimination, frequency discrimination, and electrically paired pixel transducers can be extended to more than two platens without departing from the scope of this document. For example, a fingerprint sensor similar to fingerprint sensors 4100 and 4500 can be made with three platens of three different thicknesses, and therefore can have three different round-trip propagation times. In this example, each pixel transducer of the first platen has a corresponding pixel transducer for the second platen and a corresponding pixel transducer for the third platen, so that the three pixel transducers form an electrically connected triplet that can be driven simultaneously using a waveform generator. The receiving electrode will then output three electrical pulses separated in time, each pulse uniquely corresponding to one of the platens. This concept can be similarly extended to four or more platens.

[0404] In other embodiments, a multi-platen ultrasonic fingerprint sensor combines time discrimination and frequency discrimination. For example, a fingerprint sensor may include four platens. The first and second platens have the same first round-trip propagation time, and the third and fourth platens have the same second round-trip propagation time, which is different from the first round-trip propagation time. In addition, the first and third platens can be made using pixel transducers having the same first frequency response, while the second and fourth platens can be made using pixel transducers having the same second frequency response, which is different from the first frequency response. In this case, the pixel transducers form an electrically connected quartet that can be driven simultaneously using a dual-frequency waveform. The sensed echo then causes two temporally distinguishable pulses, each pulse containing two resolvable frequencies.

[0405] Additional references Figures 25A-25D , various electrical configurations of ultrasonic sensors are illustrated in accordance with the present invention. Fig.25Both the dual-sided sensor embodiments and the large-area sensor embodiments described herein can be implemented using "time division multiplexing" (e.g., using the time axis to capture multiple reflections from different locations under the sensor in a single scan). Alternatively or additionally, "frequency division multiplexing" can be used for the same single time domain signal that provides interrogation at multiple locations under the sensor. These embodiments rely on receiving reflections from several locations under the sensor at different times. These time differences can be achieved in a variety of ways: different platen thicknesses at different sensor locations; different platen materials at different sensor locations; and / or multiple different sensors (e.g., as with a dual-sided sensor). In some embodiments, frequency division multiplexing (FDM) can be achieved by varying the thickness of the piezoelectric (e.g., a zinc oxide piezoelectric) and / or the thickness and / or type of metal layers below and above the piezoelectric. Signal processing can then be applied to the signals received from the different locations to extract the amplitude and / or phase of the signals at different locations on the underside of the sensor.

[0406] like Fig.25 As shown, two fingers (e.g., thumb and index finger) can be used to apply a compressive force (e.g., squeeze) to a sensor consisting of two back-to-back ultrasonic sensors, the two sensors having pressure plates of different thicknesses, which are attached to have common X lines (e.g., transmitting electrodes) and Y lines (receiving electrodes). Thus, each single X line (transmitting electrode) can be used to send two signals, a first signal in the first sensor and a second signal in the second sensor. The two sensors can be constructed with pressure plates of slightly different thicknesses so that the signals on the single Y line (receiving electrode) will arrive at different times (e.g., but on the same electrical connection). Measurements of the amplitude and / or phase (arrival time) of the two signals will correspond to fingerprints on the two sensors at the same XY location.

[0407] The coupling of the two sensors can be achieved in a number of ways: for example by attaching solder bumps to a flexible printed circuit board, thereby making contact to the X and Y lines in the two sensors.

[0408] The two sensors can have the same or different thicknesses, and the piezoelectric material (e.g., ZnO film) can have different thicknesses, so that the phase of the reflected signals will be different, so processing the signals in the frequency domain will allow the extraction of the amplitude and phase (arrival time) of the two signals associated with the two fingers, both signals arriving on the same electrical channel.

[0409] exist Figure 20-24In the , platens with various thicknesses at different sensor locations are shown with the same X-line and different Y-lines. The Y-lines are electrically connected one by one to have the same channels 1 to n, where n is the number of channels. In some embodiments, when one Y-line is excited, ultrasonic energy is sent from different Y-lines to interrogate platens at different locations. Due to the different thicknesses of the platens at different locations, the receiving X-ray will receive signals on the same channel at different times. Figure 20-24 Two steps in one direction are shown (i.e., two different platen thicknesses), but there is no limit to the number of steps, as long as there is sufficient spacing between reflected pulses to allow measurement of amplitude and phase at different arrival times. In this arrangement, very large area sensors can be implemented with a relatively small number of channels, allowing data acquisition and processing to be performed quickly, for example to achieve real-time operation. Alternatively, this arrangement can also be applied to sensors of any size, for example to achieve faster data acquisition.

[0410] Figures 25A-25D The diagram illustrates how resources can be shared compared to a single sensor approach. The hardware illustrated can be used to generate images from two or more sensors (essentially doubling the sensor area) using appropriate connections and time division multiplexing and / or frequency division multiplexing. Time division multiplexing and / or frequency division multiplexing can increase information density without increasing hardware or data acquisition time. Fig.25A A single 5x5 sensor connected to imaging hardware is shown. Dashed lines represent transmit lines and solid lines represent receive lines. Fig.25B Diagram showing connection to Fig.25A Two 5x5 sensors of the same hardware. Dashed lines represent transmit lines. Solid lines represent receive lines, with different flight times (e.g., achievable with multiple different platen thicknesses as described above) and / or different frequency responses (e.g., achievable with different ZnO or other piezoelectric material thicknesses), which can be combined together and separated by windowing in the time domain and / or filtering in the digital domain, respectively. Fig.25C The changes in connectivity between sensors are illustrated.

[0411] These arrangements allow for reduced hardware energy requirements per scan (e.g., very important for portable applications) since multiple ultrasound channels can share the same electrical channels and since the total data acquisition time (e.g., the time the hardware needs to be powered) is shorter. Variations of this arrangement can be used that impact data acquisition time and hardware complexity and reduce digital processing requirements by avoiding time or frequency division multiplexing. Hardware sharing remains to share the transmit electronics and receive chains since they are the primary power consumers.

[0412] Fig.25DThe same 5x5 sensor connected to the same transmit line is illustrated. On the receive side, hardware resources are shared between the two sensors except for the increased number of multiplexers used to switch between the lines.

[0413] Another arrangement for achieving different arrival times of multiple pulses is to use a platen made of different materials attached together (e.g., on the sides). For example, multiple glass square rods can be fused together and then sliced ​​horizontally to make a flat disk (e.g., a platen) with different material properties (e.g., sound speed) to, for example, allow a large area fingerprint sensor to be implemented in the manner previously described. For frequency division multiplexing, the system 10 can determine the phase difference of the signals excited at different locations while maintaining the phase difference in the X and Y directions. Figure 20-24 The electrical connection type shown. In some embodiments, the phase change can be achieved by changing the thickness of the piezoelectric material (eg, ZnO thin film).

[0414] The applicant has simulated the above arrangement, in which the output pressure is measured at a fused quartz platen and the piezoelectric ZnO film thickness is varied from 16 μm to 19 μm in steps of 1 μm. At an operating frequency of 150 MHz, the phase change is approximately 10° for every micron change in the thickness of the ZnO film. The simulation was performed using an arrangement including a metal film (e.g., gold with a thickness of 0.2 μm) above and below the ZnO film. There is sufficient phase shift at different locations of the metal film forming the electrodes of the sensor. Another way to achieve phase shift is by changing the metal above and below the piezoelectric film. An aluminum film can be used at the interface between the ZnO and the quartz platen. In the simulation, a larger phase shift was achieved when the thickness of the aluminum film was varied from 0.2 μm to 1.0 μm.

[0415] Fig.26 is a block diagram of a fingerprint sensing system 4700 using a fingerprint sensor 4100 or 4500. The fingerprint sensing system 4700 includes a real-time processor 4708 that controls a transmit multiplexer (MUX) 4703 to select which electrically paired transmit electrodes 4106, 4107 are driven by the waveform generator 4304. The real-time processor 4708 also controls a receive MUX 4702 to select which receive electrode 4108 is connected to the input of the amplifier 4402. The amplified output 4404 of the amplifier 4402 is digitized using an analog-to-digital converter (ADC) 4706, the output of which is sensor data 4716, which is then time-stamped by the real-time processor 4708. The real-time processor 4708 references a time base 4728, which references all timing. Although Fig.26 Not shown, but time base 4728 may also be used as a time and / or frequency reference for one or both of ADC 4706 and waveform generator 4304.

[0416] Processor 4708 is "real-time" because the time it takes to complete an operation is deterministic and therefore predictable (e.g., does not change based on external factors or unexpected events). Examples of real-time processors 4708 include field programmable gate arrays (FPGAs), digital signal processors (DSPs), and systems on chips (SoCs). However, real-time processor 4708 can be other types of circuits and / or chips as long as it operates deterministically.

[0417] The real-time processor 4708 sends the waveform 4500W to a computer 4710, which includes a processor 4720 and a memory 4722 storing the waveform 4500W. The memory 4722 also stores machine-readable instructions that, when executed by the processor 4720, process the waveform 4500W to determine the amplitude offset and / or time offset of the sensed pair of pixel transducers 4110, 4111. Figures 2 to 19 Further details regarding the signal processing methods used by computer 4710 are described.

[0418] The fingerprint sensing system 4700 processes the waveform 4500W for all pixel transducers 4110, 4111, from which it generates a fingerprint image. The computer 4710 can display the fingerprint image to the user via a display screen 4712, which can be integrated with the computer 4710 (e.g., a tablet device or laptop computer) or can be separate from the computer 4710 (e.g., a desktop monitor or high-definition television). Although in Fig.26 47. Not shown, computer 4710 may alternatively or additionally communicate with another computer system (e.g., via a wide area network, a local area network, the Internet, Wi-Fi, etc.) that uses the fingerprint image, such as a biometric security system that processes the fingerprint image to determine access rights to a room, computer system, file, etc. In some embodiments, real-time processor 4708 and computer 4710 are combined into one computer system.

[0419] Fig. 27 FIG. 4 is a side cross-sectional view of an ultrasonic fingerprint sensor 4800 with a wedge-shaped pressure plate 4802. The fingerprint sensor 4800 includes an ultrasonic transducer array 4804 that is connected to a Fig. 20 The transducer arrays 4104 and 4105 are similar and are located on the rear end face 4822 of the wedge-shaped pressure plate 4802. The front end face 4812 of the wedge-shaped pressure plate 4802 is not parallel to the rear end face 4822, so the thickness (in the z direction) of the wedge-shaped pressure plate 4802 increases from d 1 to d 2 Due to this varying thickness, the round trip propagation time of the ultrasound pulses emitted by the transducer array 4804 will also vary linearly in the x-direction.

[0420] The operation of the ultrasonic fingerprint sensor 4800 may be similar to that of the multi-platen ultrasonic fingerprint sensor 4100 and thus may have similar advantages. Fig. 27 As shown, a pair of transmit electrodes 4106 can be directly electrically connected to each other and driven simultaneously using a single waveform generator 4304. This arrangement will simultaneously transmit two ultrasonic pulses into the wedge-shaped pressure plate 4802, Fig. 22 The operation of the multi-plate fingerprint sensor 4100 shown is similar. Thus, Fig. 27 The pixel transducers 4110 in the embodiment may be electrically paired, similar to the electrically paired pixel transducers described above. Reflection from the front face 4812 will produce two echoes that are sensed by a single receiving electrode 4108(j), similar to Fig.23 Operation of the fingerprint sensor 4100 is shown. Due to the difference in round trip propagation time, each detected echo can be related to its spatial position along the x-direction.

[0421] Advantageously, the ultrasonic fingerprint sensor 4800 provides the same benefits as the multi-platen fingerprint sensors described herein, but may be easier to manufacture because the wedge-shaped platen 4802 has no "steps." Fig. 27 The wedge-shaped pressure plate 4802 is shown as being tilted only in the x-direction, but the wedge-shaped pressure plate 4802 may be tilted in both the x- and y-directions without departing from the scope of this document.

[0422] Embodiment with anti-reflection coating

[0423] Fig.28 Two cross-sectional side views of an anti-reflection (AR) coated ultrasonic fingerprint sensor 4900 are shown. The AR coated ultrasonic fingerprint sensor 4900 has a first AR coating 4902 deposited directly onto the front face 4112 of the platen 4102, Fig.28 The platen 4102 is shown to be made of glass. The AR coating ultrasonic fingerprint sensor 4900 has a second AR coating 4904 deposited directly onto an ultrasonic transducer array (e.g., the transducer array 4104 described herein). Thus, the second AR coating 4904 is deposited directly onto two electrodes (e.g., Fig. 20 and Fig.21 On the area of ​​the piezoelectric layer 4114 between the electrode 4106) and the electrode.

[0424] Fig.28The upper figure in FIG. 4 illustrates that the probe light 4912 propagates upward (i.e., in the +z direction), passes through the platen 4102, and enters the finger 4130 in physical contact with the first AR coating 4902. The probe light 4912 may be generated by an LED or a laser (not shown) located at the plane 4910 below the AR coating ultrasonic fingerprint sensor 4900. The second AR coating 4904 increases the transmission of the probe light 4912 into the piezoelectric layer 4114 (compared to the transmission without the second AR coating 4904) by reducing the amplitude of the reflection generated by the step function change of the refractive index between the air and the piezoelectric layer 4114 (e.g., ZnO). The first AR coating 4902 increases the transmission of the probe light 4912 into the finger 4130 (compared to the transmission without the first AR coating 4902) by reducing the amplitude of the reflection generated by the step function change of the refractive index between the platen 4102 and the finger 4130.

[0425] Fig.28 The lower figure in 4904 illustrates the transmission of signal light 4916 from the finger 4130 downward (i.e., in the -z direction) through the platen 4102. The first AR coating 4902 increases the transmission of the signal light 4916 from the finger outward and into the platen 4102, while the second AR coating 4904 increases the transmission of the signal light 4916 from the piezoelectric layer 4114 outward and into the underlying air. After exiting from the piezoelectric layer 4114, the signal light 4916 can be detected by a photodiode (not shown) located on or near the plane 4910.

[0426] The AR coated ultrasonic fingerprint sensor 4900 can be used to increase the signal-to-noise ratio (SNR) of a pulse oximeter. For example, the documents cited above (i) International Publication No. WO 2019 / 032590 and (ii) Gerard Touma, "A row-column addressed acoustic biometric scanner integrated with pulse oximetry" (Stanford University Ph.D. dissertation, 2020) show how a pulse oximeter can be combined with an ultrasonic transducer array when at least a portion of the transducer array is optically transparent. For pulse oximetry, the wavelength of the probe light 4912 is typically close to 660 nm, while the wavelength of the signal light 4916 is typically close to 940 nm. In this case, the AR coatings 4902 and 4904 can be configured to enhance transmission at both wavelengths.

[0427] Since the detection light 4912 and the signal light 4916 can propagate at the same time, the second AR coating 4904 reduces the amount of the detection light 4912 detected together with the signal light 4916, thereby reducing the noise level when detecting the signal light 4916. The first AR coating 4902 increases the signal level when detecting the signal light 4916 by increasing the amount of the detection light 4912 entering the finger 4130 and the amount of the signal light 4916 leaving the finger 4130.

[0428] Each of the AR coatings 4902 and 4904 can be configured to increase transmission at: (i) any wavelength in the infrared, optical, or ultraviolet regions of the electromagnetic spectrum, (ii) a plurality of such wavelengths (e.g., 660 nm and 940 nm), and / or (iii) over a range of wavelengths (e.g., 660-940 nm). Each of the AR coatings 4902 and 4904 can be a multilayer dielectric stack (e.g., composed of SiO 2 and Ta 2 O 5 or other materials used in dielectric stacks) or a single layer coating (e.g., MgO 2 ).

[0429] When the electrodes are made of metal, the detection light 4912 and the signal light 4916 cannot pass through the electrodes. However, the electrodes can be made of an optically transparent conductive material (e.g., indium tin oxide). When the total area of ​​the piezoelectric layer 4114 covered by the electrodes is greater than the corresponding area not covered, the second AR coating 4904 can be designed to maximize the light transmission at the interface between the air and the electrode material, rather than the interface between the air and the piezoelectric material, because this may result in an overall increase in the transmission of light through the platen 4102 in both directions. Alternatively, the second AR coating 4904 can be designed to partially (but not maximize) increase the light transmission at the interface between the air and the electrode material, and partially (but not maximize) increase the light transmission at the interface between the air and the piezoelectric material. Depending on the proportion of the area of ​​the piezoelectric layer 4114 covered by the electrodes, the refractive index of the piezoelectric layer 4114 and the electrodes, the wavelength of the detection light 4912 and the signal light 4916, and / or other factors, this alternative design can achieve maximum light transmission.

[0430] AR coatings 4902 and 4904 may be used in ultrasonic fingerprint sensors having a single platen, such as those described in (i) International Publication No. WO 2019 / 032590 and (ii) Gerard Touma, “A row-column addressed acoustic biometricscanner integrated with pulse oximetry” (Stanford University Ph.D. dissertation, 2020). AR coatings 4902 and 4904 may also be used in any one or more of any of the multi-platen ultrasonic fingerprint sensors described herein (e.g., Fig. 20 and Fig.21 The first pressure plate 4102 and the second pressure plate 4103 of the multi-pressure plate ultrasonic fingerprint sensor 4100 are shown in FIG.

[0431] In other embodiments, a screen protector for a mobile device (e.g., a smartphone or tablet device) having a touch screen includes a thin plastic sheet (e.g., polyethylene terephthalate or thermoplastic polyurethane), glass, and / or another optically transparent material. A first side of the screen protector directly contacts an outward-facing surface of the touch screen (i.e., the side of the touch screen that a user will view) to physically protect the outward-facing surface. Directly deposited onto a second side of the screen protector opposite the first side may be a Fig.28 The AR coating on the second side 4904 is similar to the AR coating on the second side. The light source and photodetector for pulse oximetry can be located behind the inward-facing surface of the touch screen, opposite the outward-facing surface, and pointing toward the touch screen. In this case, the touch screen acts similar to the pressure plate 4102, and the AR coating on the second side increases the light transmission between the screen protector and the finger in direct physical contact with the AR coating. The AR coating can be designed to increase the transmission of light used for pulse oximetry (e.g., 660nm and 940nm).

[0432] Overall Figures 29 to 45B ,use Figure 1 The label of .

[0433] Fig.29 1 is a block diagram of the hardware and software parts of the system conceived by the present invention. The system 10 includes a sensor 100 and a controller 200. The sensor 100 and the controller 200 may include various components, such as Fig.29 Those shown.

[0434] In some embodiments, the system 10 is constructed and arranged as follows Fig.30 shown. Fig.30 The sensor 100 includes a fingerprint sensor 100a and a pulse oximetry sensor 100b. Fig.30Sensor 100 also includes a collimator that includes a light absorbing material within the frequency range of pulse oximetry sensor 100b and is positioned between sensor 100b and sensor 100a to, for example, reduce clutter signals in the recording generated by sensor 100b. The collimator can be used in place of, or in addition to, the anti-reflection coating. The height and width ratio of the collimator can be configured to provide optimized transmission and reception angles.

[0435] In some embodiments, the sensor 100 includes a focusing lens, such as Fig.31 As shown. A focusing lens may be included to increase the signal-to-noise ratio (SNR), reduce misalignment, and reduce clutter signals. In some embodiments, the lens includes a Fresnel lens.

[0436] In some embodiments, the system 10 is constructed and arranged as follows Fig.32 shown. Fig.30 The sensor 100 includes a fingerprint sensor 100a and a pulse oximetry sensor 100b. Fig.30 The sensor 100 also includes a transparent, non-conductive adhesive layer to attach the sensor 100b to the sensor 100a. The adhesive layer provides permanent alignment while mechanically coupling the sensors 100a and 100b.

[0437] The sensor 100 may include a relatively large number of electronic attachment points, or "pads," such as at least 100 pads, at least 200 pads, or at least 300 pads. These pads are attached to various input channels (e.g., power and control channels) and output channels of the sensor. The user device 500 may include a front-end ASIC (e.g., located near the sensor 100) that converts the numerous channels (e.g., analog channels) of the sensor 100 into fewer (e.g., one) channels (e.g., one or a few digital channels).

[0438] In some embodiments, user device 500 comprises a smart card and sensor 100 comprises an ultrasound-based sensor constructed of PVDF, wherein sensor 100 is positioned at a selected depth from a first surface of the smart card such that ultrasound transmission passes only a portion of the full thickness of the smart card.

[0439] In some embodiments, user device 500 comprises a smart card, and sensor 100 comprises an ultrasound-based sensor composed of zinc oxide (ZnO) positioned on a small glass portion of the smart card. In some embodiments, the glass portion comprises a scratch-resistant coating.

[0440] In some embodiments, user device 500 comprises a cellular telephone and sensor 100 comprises an ultrasound-based sensor positioned within a housing of the phone (e.g., housing 510 comprising an acoustically transparent metal housing), and ultrasound transmission to and from sensor 100 is configured to pass through the housing.

[0441] In some embodiments, the sensor 100 (eg, an ultrasound-based sensor) is configured to identify a user based on an image of the user's palm (eg, in addition to or as an alternative to a fingerprint).

[0442] Ultrasonic sensor combined with capacitive sensor

[0443] In some embodiments, the sensor 100 includes a sensor 100a including an ultrasound-based sensor and a sensor 100b including a capacitive touch sensor (eg, operating at a DC level).

[0444] In some embodiments, the sensor 100 includes an ultrasound-based sensor (e.g., sensor 100a described above) that includes a layer of ZnO that is positioned behind (e.g., sputtered onto) a display screen (e.g., a display screen of a cell phone or other user device 500). In these embodiments, sound generated and received by the sensor 100 passes through the display screen. In some embodiments, the display screen (e.g., user interface 550) includes: LCD, OLED and / or microLED layers (e.g., including substrates, thin film transistors, liquid crystals, color filters, packaging, etc.); a capacitive sensor matrix (e.g., sensor 100b as described above, which includes electrodes, insulators, thin film transistors, passivation layers, etc.); one or more thin (e.g., about 1 μm, 2 μm, or 3 μm, such as up to 50 μm or 75 μm) optically clear adhesive layers (e.g., between one or more other layers); and / or a glass cover layer. The display layers can be uniformly constructed and arranged, can be acoustically conductive, and can include minimal air gaps or no air gaps.

[0445] Similarly, in some embodiments, sensor 100 includes an ultrasound-based sensor 100a that is positioned behind (e.g., splashed onto) a sensor 100b that includes a capacitive touch sensor. In these embodiments, sound generated and received by sensor 100a passes through sensor 100b.

[0446] In some embodiments, the sensor 100 may include an ultrasound-based sensor 100a positioned within a layer of a sensor 100b, on and / or between layers of a housing 510 of the device 500, and / or between layers of a display screen (e.g., a display screen of a user interface 550 of the device 500). In these embodiments, the sound generated and received by the sensor 100a passes through various layers of the sensor 100b and / or layers of the display screen (e.g., as described above), which are located between the sensor 100a and the tissue of the user (e.g., the tissue of the user's finger). The sensor 100b, the housing 510 of the device 500, and / or the user interface 550 may include a transparent insulator film surrounded by two linear electrode layers (e.g., orthogonal linear electrode layers, or linear electrode layers arranged at angles between 1° and 89°), which are relatively transparent and may be composed of indium tin oxide. This configuration allows light to pass through (e.g., with an optical transmittance of about 94%). Sensor 100a may be positioned within two of these wire electrode layers, for example by depositing a piezoelectric film in place of an insulator film (e.g., so that the sound passes through fewer layers than if sensor 100a were positioned behind a mating component). This construction of an ultrasound-based sensor 100a in combination with a capacitive touch sensor (e.g., of sensor 100b, housing 510 of device 500, and / or user interface 550) may provide a single assembly that may perform one, two, three, or more functions selected from the group consisting of: ultrasonic fingerprint detection; capacitive fingerprint detection; ultrasonic touch sensing (e.g., position sensing); capacitive touch sensing; force sensing (e.g., via capacitive or ultrasound-based measurements); tactile feedback; acoustic feedback; and combinations of these.

[0447] Figures 33A-33B The configuration of a user interface 550 is illustrated, which includes a capacitive touch sensor 100b (e.g., operating at a DC level), as described above. An ultrasound-based sensor 100a, not shown but including a piezoelectric film and operating in the MHz range as described herein, may be positioned between two or more of the various layers shown. Alternatively or additionally, the sensor 100a may be replaced with a Fig.33A One of the layers shown.

[0448] Operation Area

[0449] In some embodiments, sensor 100 includes sensor 100a and sensor 100b, sensor 100a includes an ultrasound-based sensor and sensor 100b includes a capacitive touch sensor, as described above. Sensor 100a can be positioned below sensor 100b (e.g., from the user's perspective). System 10 can be configured such that user contact with sensor 100b (e.g., contact via a user's finger) is used to change the current state of user device 500, such as making a state change selected from a group including the following: off to on; standby mode to wake-up mode; low power mode to non-low power mode; silent mode to non-silent mode; and combinations of these. In some embodiments, sensor 100 is configured such that user contact along a top surface portion of sensor 100 (e.g., continuous finger contact) can be configured via sensor 100b to define an "operation zone" so that system 10 can be used in subsequent events (e.g., a user can dynamically set one or more operation zones to a subset of a relatively large sensor 100 surface area). For example, one or more of these user-defined operating zones can be associated with one or more "active zones" of sensor 100a (e.g., one or more subsets of the entire area of ​​sensor 100 where sensor 100a will actively image the user's contact portion). These limited-area active zones can be used to reduce power consumption, and / or reduce the amount of data collected by sensor 100a (e.g., for faster data collection, processing, and / or matching). Multiple active zones can be created, and each can be assigned to similar and / or different functions (e.g., different functions of a gaming application or other application of device 500), so that either or both sensors 100a and / or 100b can associate functionality with a user's contact with a particular active zone.

[0450] In some embodiments, the device 500 is configured for use by multiple users, each of which controls a particular cursor of the user interface 550. In these embodiments, the system 10 can associate a particular cursor (e.g., from a group of cursors of different colors, shapes, emojis, and / or other different graphical parameters) with a particular user by their fingerprint. Once detected, the user can continue the association with the cursor by continued contact of their finger. If the finger contact is lost, the user can perform re-association (e.g., select the same cursor), and / or perform detection of the user by repeatedly analyzing the user's fingerprint (e.g., automatic detection).

[0451] In some embodiments, an ultrasound-based sensor 100 (e.g., sensor 100a described above) is used to determine one or more operating zones (e.g., with or without the use or even presence of a capacitive touch-based sensor (e.g., sensor 100b just described above)). For example, the ultrasound-based sensor 100 may utilize pulse echoes on all of its ultrasonic transducers (also referred to herein as “channels”) to quickly detect a user's contact location (e.g., a user's finger), and subsequently define an operating zone around the contact location (e.g., including a buffer zone around the detected contact location). Alternatively or additionally, the ultrasound-based sensor 100 may provide drive signals to a small fraction of the total number of ultrasound sensors (e.g., an equally spaced distribution of less than 20% of the total number of sensors), and the sensor 100 may use reflections of these signals to locate the user's contact point, and use this contact point as an operating zone (e.g., with or without an accompanying buffer zone).

[0452] Langevin transducer based sensors

[0453] In some embodiments, the sensor 100 includes a sensor based on a Langevin transducer (or its equivalent). In normal operation, the piezoelectric body resonates when the thickness of the piezoelectric body is half the wavelength of the drive signal, and resonates at higher frequencies when the thickness of the piezoelectric body is an odd multiple of half the wavelength. The sensor 100 may include a Langevin transducer, which includes an assembly, which includes a piezoelectric element and an attachment element of a specific mass. These Langevin sensors resonate at a frequency where the thickness of the assembly (piezoelectric transducer thickness plus attachment element thickness) is half the wavelength of the drive signal, and resonate at a high frequency where the thickness of the assembly is an odd multiple of half the wavelength. The sensor 100 may include a Langevin transducer, which includes an attachment element that is much thicker than the piezoelectric element, for example, to create an assembly whose resonant frequency is much lower than the resonant frequency of the piezoelectric element when it is not connected to the attachment element.

[0454] In some embodiments, the sensor 100 includes an ultrasound-based sensor that includes one or more piezoelectric elements (e.g., zinc oxide piezoelectric elements) having a specific thickness (e.g., 16 μm). The sensor 100 includes a specific area (e.g., 1 mm by 1 mm, 5 mm by 5 mm, etc.), all row electrodes are connected together, and all column electrodes are connected together. The controller 200 can uniformly drive a group of multiple piezoelectric elements (e.g., all or a portion of the total number of piezoelectric elements of the sensor 100) so that the group of piezoelectric transducers functions as a signal sensor (e.g., a low-frequency sensor) to, for example, send and receive ultrasonic energy to tissue (e.g., a user's finger) to perform Doppler ultrasound measurements (e.g., measurements of blood flow, heart rate, etc.). For example, system 10 may include a system comprising a plurality of piezoelectric elements that can be configured (e.g., via controller 200) as Langevin transducers, wherein system 10 is capable of perfor...

Claims

1. A user classification system, comprising: A sensor configured to generate a sensor signal, the sensor comprising: The controller is configured as: providing a drive signal to be transmitted by the transducer as an ultrasonic pulse; and receiving and processing the signals recorded by the sensor, wherein the signal recorded by the sensor comprises one or more recorded reflections of an ultrasonic pulse transmitted by the sensor; and User equipment, The system is configured to classify a user of the user device based on the sensor signal.

2. The system of claim 1 and / or any one or more other claims herein, wherein: The controller is configured to implement a beamforming technique.

3. The system of claim 2 and / or any one or more other claims herein, wherein: The beamforming technique includes time domain beamforming.

4. The system of claim 2 and / or any one or more other claims herein, wherein: The beamforming technique includes frequency domain beamforming.

5. The system of claim 4 and / or any one or more other claims herein, wherein: The frequency domain beamforming is achieved by oversampling the recorded signal.

6. The system of claim 4 and / or any one or more other claims herein, wherein: The frequency domain beamforming is implemented using IQ sampling.

7. The system of claim 6 and / or any one or more other claims herein, wherein: The controller includes an IQ demodulator.

8. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor also includes a first ultrasound layer.

9. The system of claim 8 and / or any one or more other claims herein, wherein: The user device further comprises a display, and wherein the first ultrasound layer is located on a lower side of the display.

10. The system of claim 9 and / or any one or more other claims herein, wherein: The sensor further comprises a second ultrasound layer, and wherein the second ultrasound layer is located on the underside of the display.

11. The system of claim 8 and / or any one or more other claims herein, wherein: The first ultrasound layer includes a boundary, and wherein the controller is located outside the boundary.

12. The system of claim 8 and / or any one or more other claims herein, wherein: The first ultrasonic film layer includes a piezoelectric material.

13. The system of claim 12 and / or any one or more other claims herein, wherein: The piezoelectric material includes PVDF.

14. The system of claim 12 and / or any one or more other claims herein, wherein: The piezoelectric material includes a 0-3 type piezoelectric composite material.

15. The system of claim 1 and / or any one or more other claims herein, wherein: The controller includes one or more thin film transistor components.

16. The system of claim 1 and / or any one or more other claims herein, wherein: The controller includes one or more resonant circuits configured to increase a transmitted pressure of the sensor.

17. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor includes a substrate and one or more ultrasonic thin film layers, wherein the user device includes a display, and wherein the one or more ultrasonic thin film layers are located between the substrate and the display.

18. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor is fabricated using a layered deposition process.

19. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor is manufactured with reference to the contents described in the specification and drawings herein.

20. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor includes two or more sensors.

21. The system of claim 20 and / or any one or more other claims herein, wherein: The sensor includes a first sensor and a second sensor, and wherein the second sensor is constructed and arranged differently from the first sensor.

22. The system of claim 1 and / or any one or more other claims herein, further comprising a processing unit comprising a processor and a memory storage component coupled to the processor, wherein: The memory storage component stores instructions for the processor to execute an algorithm.

23. The system of claim 22 and / or any one or more other claims herein, wherein: The algorithm includes weighting factors and / or biases that prioritize one user identification over another.

24. The system of claim 22 and / or any one or more other claims herein, wherein: The sensor comprises an array of pixel elements, and wherein the algorithm comprises an artificial intelligence algorithm and / or other algorithm configured to determine which subset of pixel elements in the array of pixel elements to use for imaging a fingerprint or other object.

25. The system of claim 24 and / or any one or more other claims herein, wherein: The algorithm is configured to compensate for damage to the housing or other parts of the sensor.

26. The system of claim 24 and / or any one or more other claims herein, wherein: The user device includes a housing and a cover surrounding at least a portion of the housing, and wherein the algorithm is configured to adjust the cover.

27. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor is configured to provide multi-cycle ultrasound signal bursts.

28. The system of claim 1 and / or any one or more other claims herein, wherein: The user device comprises a user interface including a display, and wherein the sensor is located below the display.

29. The system of claim 1 and / or any one or more other claims herein, wherein: The user device comprises a housing, and wherein the sensor is constructed and arranged to transmit and / or receive ultrasound signals through at least a portion of the housing.

30. The system of claim 29 and / or any one or more other claims herein, wherein: The at least a portion of the housing includes a metal having a thickness of at least 100 μm, no greater than 5 mm, or both.

31. The system of claim 29 and / or any one or more other claims herein, wherein: The at least a portion of the housing includes an edge of the housing and / or a side of the housing.

32. The system of claim 31 and / or any one or more other claims herein, wherein: The sensor includes a first sensor disposed near a first edge of the housing and a second sensor disposed near a second edge of the housing.

33. The system of claim 32 and / or any one or more other claims herein, wherein: The first sensor is different from the second sensor in construction and arrangement.

34. The system of claim 31 and / or any one or more other claims herein, wherein: The user device comprises buttons and / or other user controls, and wherein the sensor is located near the buttons and / or other user controls.

35. The system of claim 31 and / or any one or more other claims herein, wherein: The housing includes aluminum, titanium and / or other metals.

36. The system of claim 29 and / or any one or more other claims herein, wherein: The sensor comprises a substrate, and wherein the substrate is attached to the housing.

37. The system of claim 36 and / or any one or more other claims herein, wherein: The thickness of the substrate is equal to nλ / 2±λ / 4, where λ is set by the operating frequency of the sensor and the speed of sound in the material of the substrate.

38. The system of claim 36 and / or any one or more other claims herein, wherein: The substrate includes an insulating material.

39. The system of claim 38 and / or any one or more other claims herein, wherein: The substrate is configured as an acoustic matching layer between the sensor and the housing.

40. The system of claim 36 and / or any one or more other claims herein, wherein: The sensor includes row electrodes and column electrodes, and wherein the thickness of the substrate is not less than a spacing between the row electrodes and the column electrodes.

41. The system of claim 1 and / or any one or more other claims herein, wherein: The system includes a calibration routine.

42. The system of claim 41 and / or any one or more other claims herein, wherein: The user device includes a housing and a cover surrounding at least a portion of the housing, and the calibration routine is configured to compensate for the presence of the cover.

43. The system of claim 1 and / or any one or more other claims herein, wherein: The system is configured to record fingerprints from a plurality of different fingers, and wherein the system is configured to assign use of each fingerprint to a different set of instructions executed by the user device.

44. The system of claim 43 and / or any one or more other claims herein, wherein: The instruction set is configured to perform a function of the user device selected from the group consisting of: transitioning from a locked state to an unlocked state; transitioning from an unlocked state to a locked state; causing a screen of a user interface to go blank or otherwise change state; dialing a specific person's phone number; entering an alarm state; dialing 911; entering a specific software program; and combinations thereof.

45. The system of claim 43 and / or any one or more other claims herein, wherein: Different fingerprints are independently associated with the task of unlocking a device with associated user permission levels.

46. ​​The system of claim 1 and / or any one or more other claims herein, wherein: The user device is configured to operate in a detection mode and enter an imaging mode when the presence of a finger is detected, wherein the detection mode is configured to detect when a finger is placed on the sensor and / or otherwise close to the sensor, and the imaging mode is configured to image a fingerprint or other object.

47. The system of claim 46 and / or any one or more other claims herein, wherein: The power consumption of the user equipment in the detection mode is lower than that in the imaging mode.

48. The system of claim 46 and / or any one or more other claims herein, wherein: The user device is configured to switch back to detection mode after capturing the fingerprint.

49. The system of claim 46 and / or any one or more other claims herein, wherein: The detection mode is configured to operate at a frame rate of at least 5 fps.

50. The system of claim 46 and / or any one or more other claims herein, wherein: The sensor has a transmitting channel and a receiving channel, and wherein the detection mode uses fewer transmitting channels and / or receiving channels than the imaging mode.

51. The system of claim 1 and / or any one or more other claims herein, wherein: The user equipment is configured to measure an average signal reduction over a surface of the sensor.

52. The system of claim 51 and / or any one or more other claims herein, wherein: The measurement of the average signal reduction is used to determine the position of the finger on the sensor.

53. The system of claim 52 and / or any one or more other claims herein, wherein: The sensor is configured to provide a writing tablet functionality.

54. The system of claim 52 and / or any one or more other claims herein, wherein: The sensor is configured to control a cursor of the user device.

55. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor is configured to detect various gestures of the user.

56. The system of claim 55 and / or any one or more other claims herein, wherein: The various gestures include: tapping; double-tapping; and / or sliding in one or more directions.

57. The system of claim 55 and / or any one or more other claims herein, wherein: The detection of a specific gesture is configured to perform a function selected from the group consisting of: locking the user device; unlocking the user device; adjusting the volume of the user device; minimizing and / or maximizing an application displayed on a user interface of the user device; adjusting the brightness of the user interface of the user device; and combinations thereof.

58. The system of claim 1 and / or any one or more other claims herein, wherein: The sensors include ultrasonic sensors and capacitive sensors.

59. The system of claim 58 and / or any one or more other claims herein, wherein: The user device is configured to operate in a detection mode configured to detect when a finger is placed on and / or otherwise in proximity to the sensor, and wherein, when operating in the detection mode, both the capacitive sensor and the ultrasonic sensor are enabled.

60. The system of claim 58 and / or any one or more other claims herein, wherein: The user device is configured to use the ultrasonic sensor and / or the capacitive sensor alone and / or in combination to: reduce power consumption; sensitize and / or otherwise increase detection thresholds; and / or enhance user experience.

61. The system of claim 1 and / or any one or more other claims herein, wherein: The sensors include a first sensor and a second sensor, wherein the user device is configured to allow and / or require a user to place a first finger on the first sensor and a second finger on the second sensor, and wherein the first finger is opposite to the second finger.

62. The system of claim 61 and / or any one or more other claims herein, wherein: At least a partial fingerprint image can be captured from each of the first finger and the second finger.

63. The system of claim 1 and / or any one or more other claims herein, wherein: The user equipment is configured to provide different levels of user identification.

64. The system of claim 63 and / or any one or more other claims herein, wherein: The different levels of user identification include: a first, lower security level of identification based on a single fingerprint image; a second, higher security level of identification based on multiple fingerprint images recorded sequentially and / or simultaneously from one or more of the sensors; and / or a third, more secure level of identification based on multiple fingerprint images recorded simultaneously and / or sequentially from one or more sensors.

65. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor includes a first sensor and a second sensor configured as a multi-platen sensor.

66. The system of claim 65 and / or any one or more other claims herein, wherein: The user device includes a housing, and wherein a first portion of the housing proximate the first sensor has a different thickness than a second portion of the housing proximate the second sensor.

67. The system of claim 66 and / or any one or more other claims herein, further comprising a controller, wherein the controller is configured to drive and / or sense the first sensor and the second sensor simultaneously.

68. The system of claim 1 and / or any one or more other claims herein, wherein: The system is configured to record a plurality of A-scans, and wherein the system is further configured to perform image reconstruction without determining a temporal sequence of each A-scan.

69. The system of claim 68 and / or any one or more other claims herein, wherein: The system is configured to determine amplitude and phase only.

70. The system of claim 1 and / or any one or more other claims herein, wherein: The system is configured to determine amplitude and phase information using IQ sampling.

71. The system of claim 1 and / or any one or more other claims herein, wherein: The user device comprises a housing, and wherein the sensor comprises one or more non-square arrays proximate an edge and / or side of the housing.

72. The system of claim 71 and / or any one or more other claims herein, wherein: Each of the one or more non-square arrays comprises a rectangular array including a different number of transmit and receive channels.

73. The system of claim 71 and / or any one or more other claims herein, wherein: Each of the one or more non-square arrays has a width less than 2 mm, a length of at least 6 mm, or both.

74. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor includes pixel elements of a first resolution, and wherein the system is configured to reconstruct an image at a resolution higher than the first resolution using ultrasound beamforming.

75. The system of claim 74 and / or any one or more other claims herein, wherein: The sensor includes column electrodes and row electrodes, and wherein a density of a set of focal spots formed by the beamforming is greater than a pitch of the column electrodes, greater than a pitch of the row electrodes, or both.

76. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor comprises pixel elements and one or more sparse ultrasound arrays, and wherein each array is configured to use a sparse distribution of the pixel elements.

77. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor includes pixel elements, and wherein the system is configured to compensate for one or more faulty pixel elements using a sparse array technique.

78. The system of claim 77 and / or any one or more other claims herein, wherein: The system is configured to record an image at a resolution of at least 500 dpi when 10% or more of the pixel elements fail.

79. The system of claim 78 and / or any one or more other claims herein, wherein: The system is configured to record an image at a resolution of at least 500 dpi when 20% or more, 30% or more, 40% or more, and / or 50% or more of the pixel elements are faulty.

80. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor is configured to collect A-scans, and wherein the sensor is further configured to process a plurality of discrete time samples for each A-scan.

81. The system of claim 80 and / or any one or more other claims herein, wherein: The sensor is configured to process a single time sample for each pulse of the ultrasound signal and average the results of each time sample to reconstruct the fingerprint image.

82. The system of claim 80 and / or any one or more other claims herein, wherein: The multiple discrete time samples processed represent multiple A-scans based on each focus, which improves the signal-to-noise ratio of the reconstructed image.

83. The system of claim 1 and / or any one or more other claims herein, wherein: The system is configured to use ultrasound beamforming by controlling the number of bits based on the phase resolution used.

84. The system of claim 83 and / or any one or more other claims herein, wherein: The system is configured to achieve a phase resolution of eight levels or less using a three-bit control system.

85. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor comprises multiple layers, and wherein two or more of the multiple layers together comprise a thickness configured to establish acoustic resonance.

86. The system of claim 85 and / or any one or more other claims herein, wherein: The first layer among the two or more layers includes a substrate layer, the second layer among the two or more layers includes an electrode layer, and / or the third layer among the two or more layers includes a glue layer.

87. The system of claim 86 and / or any one or more other claims herein, wherein: The user device comprises a housing, and wherein a third layer comprising a glue layer connects the sensor to the housing.

88. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor comprises multiple layers, and wherein one or more of the multiple layers are configured to reduce a resonant frequency of the sensor.

89. The system of claim 1 and / or any one or more other claims herein, wherein: The controller is further configured to provide a drive signal at an adjustable frequency.

90. The system of claim 89 and / or any one or more other claims herein, wherein: The controller includes a calibration routine configured to determine an optimized frequency of a drive signal provided to the sensor.

91. The system of claim 90 and / or any one or more other claims herein, wherein: The sensor comprises two or more parts, and wherein the calibration routine is configured to independently calibrate the drive signal for one or more of the two or more parts.

92. The system of claim 90 and / or any one or more other claims herein, wherein: The calibration routine is configured to optimize the drive signal based on variability of one or more sensor parameters.

93. The system of claim 90 and / or any one or more other claims herein, wherein: The calibration routine is configured to adjust the drive signal to accommodate one or more environmental factors.

94. The system of claim 93 and / or any one or more other claims herein, wherein: The one or more environmental factors include temperature, humidity, or both.

95. The system of claim 93 and / or any one or more other claims herein, wherein: The sensor is further configured to generate a signal related to temperature, and wherein the calibration routine adjusts the drive signal based on the signal related to the temperature of the sensor.

96. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor is optimized to operate within a temperature range that is within 10°C of body temperature.

97. The system of claim 96 and / or any one or more other claims herein, wherein: The controller is configured to prevent user classification when the temperature of the sensor is outside the temperature range.

98. The system of claim 96 and / or any one or more other claims herein, wherein: The user device is configured to indicate to the user to adjust the temperature of the sensor when the temperature of the sensor exceeds the temperature range.

99. The system of claim 96 and / or any one or more other claims herein, wherein: The system is configured to provide a first level of authentication and a second level of authentication, wherein the first level of authentication comprises a higher level of authentication than the second level of authentication, and wherein the controller is configured to prevent user classification at the first level of authentication when the temperature of the sensor is outside the temperature range.

100. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor includes one or more apodization sections configured to compensate for a natural focus of the sensor.

101. The system of claim 100 and / or any one or more other claims herein, wherein: The sensor includes row electrodes extending along a long dimension of the sensor and column electrodes extending along a short dimension of the sensor.

102. The system of claim 101 and / or any one or more other claims herein, wherein: The column electrode comprises a taper proximate an edge of a long dimension of the sensor, and wherein the one or more apodized portions comprise the taper.

103. The system of claim 101 and / or any one or more other claims herein, wherein: Each of the row electrodes comprises a width and an inter-electrode spacing, wherein the inter-electrode spacing increases near an edge of a long dimension of the sensor and / or the width of each electrode decreases near an edge of the long dimension of the sensor, and wherein the one or more toe-off portions comprise an increased inter-electrode spacing and / or a decreased electrode width.

104. The system of claim 1 and / or any one or more other claims herein, wherein: The sensor includes one or more receive channels, wherein the controller includes an array of one or more amplifiers, and wherein the array of one or more amplifiers includes two amplifiers for each of the one or more receive channels.

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