Temperature measurement via ultrasonic sensor

Abstract

Some disclosed methods involve capturing a first ultrasonic signal corresponding to a reflection from a cover / air interface of a device including an ultrasonic sensor system, and determining one or more first ultrasonic signal parameters of the first ultrasonic signal. Some methods involve capturing a second ultrasonic signal corresponding to a reflection from a cover / target interface, and determining one or more second ultrasonic signal parameters of the second ultrasonic signal. Some methods involve estimating the temperature of a target object based at least in part on one or more first ultrasonic signal parameters, one or more second ultrasonic signal parameters, and the temperature of the ultrasonic sensor system. Some disclosed methods involve receiving ultrasonic sensor system temperature data indicating the temperature of the ultrasonic sensor system and calibrating the ultrasonic sensor system based on the temperature.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Patent Application No. 17 / 247,998, filed January 4, 2021, entitled “TEMPERATURE MEASUREMENT VIAULTRASONIC SENSOR”, which is hereby incorporated by reference. Technical Field

[0003] This disclosure generally relates to sensor devices and related methods, including but not limited to ultrasonic sensor systems and methods for using such systems.

[0004] Related technical descriptions

[0005] Biometric authentication can be an important feature used to control access to devices, etc. Many existing products include some type of biometric authentication. While some existing biometric authentication technologies provide satisfactory performance under certain conditions, improvements in methods and devices are still desired.

[0006] Overview

[0007] The systems, methods, and apparatus disclosed herein each have several innovative aspects, and no single aspect is solely responsible for the desired properties disclosed herein.

[0008] One innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus. The apparatus may include an ultrasonic sensor system, a control system, and a cover. In some examples, the ultrasonic sensor system may include a piezoelectric layer, ultrasonic sensor system electrodes proximate a first side of the piezoelectric layer, and an ultrasonic sensor pixel array proximates a second side of the piezoelectric layer. In some implementations, the apparatus may include a temperature sensor configured to determine the temperature of the ultrasonic sensor system. In some examples, the apparatus may be integrated into a mobile device.

[0009] In some examples, at least a portion of the control system is coupled (e.g., electrically or wirelessly) to the ultrasonic sensor system. The control system may include one or more general-purpose single-chip or multi-chip processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or combinations thereof.

[0010] According to some examples, the control system can be configured to receive temperature data from an ultrasonic sensor system from a temperature sensor. In some instances, the ultrasonic sensor system temperature data can indicate the temperature of the ultrasonic sensor system. In some examples, the control system can be configured to capture a first ultrasonic signal via the ultrasonic sensor system. The first ultrasonic signal can be received by electrodes of the ultrasonic sensor system and can correspond to a reflection from the cover / air interface. According to some examples, the control system can be configured to determine one or more first ultrasonic signal parameters of the first ultrasonic signal.

[0011] In some examples, the control system may be configured to capture a second ultrasonic signal from a target approaching the cover via an ultrasonic sensor system. In some instances, the second ultrasonic signal may be received by electrodes of the ultrasonic sensor system and may correspond to a reflection from the cover / target interface. According to some examples, the control system may be configured to determine one or more second ultrasonic signal parameters. In some instances, the control system may be configured to estimate the target object temperature based at least in part on one or more first ultrasonic signal parameters, one or more second ultrasonic signal parameters, and the ultrasonic sensor system temperature.

[0012] In some implementations, the device may include a memory. In some such implementations, the control system may be further configured to retrieve previously captured ultrasonic signal parameter data and previously captured temperature data from the memory, and to estimate the temperature of the target object based at least in part on the previously captured ultrasonic signal parameter data and previously captured temperature data.

[0013] In some examples, the target object may be a body part of the user of the device. In some such examples, previously captured ultrasound signal parameter data and previously captured temperature data may have been previously captured from the user (e.g., via the control system) during the user calibration phase.

[0014] In some implementations, the device may include a user interface system. In some such examples, the control system may be further configured to control the user interface system to provide one or more user prompts. In some examples, the user interface system may include a display stack. According to some examples, the cover may be or may include a cover glass. At least a portion of the display stack may reside between the cover glass and the ultrasonic sensor system. However, in some instances, some or all of the cover may be optically opaque.

[0015] In some implementations, the control system may be further configured to control the display stack to present a graphical user interface indicating the area of ​​the ultrasound sensor system. According to some implementations, the control system may be configured to control the display stack to present text during the user calibration phase, before capturing a first ultrasound signal, or both during the user calibration phase and before capturing a first ultrasound signal, prompting the user to ensure that no object is on or near the ultrasound sensor system area before capturing an ultrasound signal corresponding to a reflection from the cover / air interface. In some examples, the control system may be configured to control the display stack to present text during the user calibration phase, before capturing a second ultrasound signal, or both during the user calibration phase and before capturing a second ultrasound signal, prompting the user to position a body part on the ultrasound sensor system area before capturing an ultrasound signal corresponding to a reflection from the cover / body part interface. According to some examples, the control system may be further configured to control the display stack to present a graphical user interface indicating the user's estimated body temperature.

[0016] In some instances, previously captured ultrasound signal parameter data and previously captured temperature data may not have been previously captured from the user's body part. In some such examples, previously captured ultrasound signal parameter data and previously captured temperature data may have been captured from multiple individuals. In some instances, previously captured ultrasound signal parameter data and previously captured temperature data may have been captured via multiple devices.

[0017] According to some examples, one or more first ultrasonic signal parameters and one or more second ultrasonic signal parameters may include frequency, amplitude, phase, and / or attenuation coefficient. In some instances, capturing the first and second ultrasonic signals involves controlling an ultrasonic sensor system to emit ultrasonic waves according to each of a plurality of modes. According to some examples, each of these modes may correspond to a different combination of ultrasonic sensor system parameters.

[0018] In some examples, the control system may be configured to perform an authentication process based at least in part on ultrasonic signals received via an ultrasonic sensor pixel array. According to some examples, the control system may be configured to cause the piezoelectric layer to emit ultrasonic waves by applying a voltage to the electrodes of the ultrasonic sensor system. In some examples, the second ultrasonic signal may also correspond to a reflection from within the target object.

[0019] Other inventive aspects of the subject matter described in this disclosure can be implemented in a method. In some examples, the method may involve receiving temperature data from an ultrasonic sensor system, the temperature sensor being configured to determine the ultrasonic sensor system temperature. The ultrasonic sensor system temperature data may, for example, indicate the ultrasonic sensor system temperature. In some examples, the method may involve capturing a first ultrasonic signal via the ultrasonic sensor system. In some instances, the first ultrasonic signal may correspond to a reflection from a cover / air interface. The cover / air interface may be an interface between air and a cover comprising the ultrasonic sensor system.

[0020] In some examples, the method may involve determining one or more first ultrasonic signal parameters of a first ultrasonic signal. In some examples, the method may involve capturing a second ultrasonic signal from a target approaching a cover via an ultrasonic sensor system. In some instances, the second ultrasonic signal may be received by electrodes of the ultrasonic sensor system and may correspond to a reflection from the cover / target interface. In some examples, the method may involve determining one or more second ultrasonic signal parameters of the second ultrasonic signal. In some examples, the method may involve estimating a target object temperature based at least in part on one or more first ultrasonic signal parameters, one or more second ultrasonic signal parameters, and the ultrasonic sensor system temperature. According to some examples, the method may involve controlling a display to present a graphical user interface indicating the estimated target object temperature.

[0021] According to some examples, the method may involve retrieving previously captured ultrasound signal parameter data and previously captured temperature data from memory, and estimating the temperature of the target object based at least in part on the previously captured ultrasound signal parameter data and previously captured temperature data.

[0022] In some examples, the target object can be a body part of the user of the device. In some examples, previously captured ultrasound signal parameter data and previously captured temperature data may have been captured from the user during the user calibration phase.

[0023] According to some examples, an ultrasonic sensor system may include a piezoelectric layer. Electrodes of the ultrasonic sensor system may be accessible to a first layer of the piezoelectric layer, and an array of ultrasonic sensor pixels may be accessible to a second layer of the piezoelectric layer. In some instances, a first ultrasonic signal may be received by the ultrasonic sensor system electrodes. In some examples, the method may involve performing an authentication process based at least in part on the ultrasonic signal received via the ultrasonic sensor pixel array. According to some examples, the method may involve causing the piezoelectric layer to emit ultrasonic waves by applying a voltage to the ultrasonic sensor system electrodes.

[0024] In some examples, one or more first ultrasonic signal parameters and one or more second ultrasonic signal parameters may include frequency, amplitude, phase, and / or attenuation coefficient. According to some examples, capturing the first and second ultrasonic signals may involve controlling an ultrasonic sensor system to emit ultrasonic waves according to each of a plurality of modes. Each of these modes may correspond to a different combination of ultrasonic sensor system parameters.

[0025] Some or all of the operations, functions, and / or methods described herein may be performed by one or more devices according to instructions (e.g., software) stored on one or more non-transient media. Such non-transient media may include memory devices such as those described herein, including but not limited to random access memory (RAM) devices, read-only memory (ROM) devices, etc. Accordingly, some innovative aspects of the subject matter described herein may be implemented in one or more non-transient media on which software is stored. For example, the software may include instructions for controlling one or more devices to perform methods.

[0026] In some examples, the method may involve receiving temperature data of an ultrasonic sensor system from a temperature sensor configured to determine the ultrasonic sensor system temperature. The ultrasonic sensor system temperature data may, for example, indicate the ultrasonic sensor system temperature. In some examples, the method may involve capturing a first ultrasonic signal via the ultrasonic sensor system. In some instances, the first ultrasonic signal may correspond to a reflection from a cover / air interface. The cover / air interface may be an interface between air and a cover comprising the ultrasonic sensor system.

[0027] In some examples, the method may involve determining one or more first ultrasonic signal parameters of a first ultrasonic signal. In some examples, the method may involve capturing a second ultrasonic signal from a target approaching a cover via an ultrasonic sensor system. In some instances, the second ultrasonic signal may be received by electrodes of the ultrasonic sensor system and may correspond to a reflection from the cover / target interface. In some examples, the method may involve determining one or more second ultrasonic signal parameters of the second ultrasonic signal. In some examples, the method may involve estimating a target object temperature based at least in part on one or more first ultrasonic signal parameters, one or more second ultrasonic signal parameters, and the ultrasonic sensor system temperature. According to some examples, the method may involve controlling a display to present a graphical user interface indicating the estimated target object temperature.

[0028] According to some examples, the method may involve retrieving previously captured ultrasound signal parameter data and previously captured temperature data from memory, and estimating the temperature of the target object based at least in part on the previously captured ultrasound signal parameter data and previously captured temperature data.

[0029] In some examples, the target object can be a body part of the user of the device. In some examples, previously captured ultrasound signal parameter data and previously captured temperature data may have been captured from the user during the user calibration phase.

[0030] According to some examples, an ultrasonic sensor system may include a piezoelectric layer. Electrodes of the ultrasonic sensor system may be accessible to a first layer of the piezoelectric layer, and an array of ultrasonic sensor pixels may be accessible to a second layer of the piezoelectric layer. In some instances, a first ultrasonic signal may be received by the ultrasonic sensor system electrodes. In some examples, the method may involve performing an authentication process based at least in part on the ultrasonic signal received via the ultrasonic sensor pixel array. According to some examples, the method may involve causing the piezoelectric layer to emit ultrasonic waves by applying a voltage to the ultrasonic sensor system electrodes.

[0031] In some examples, one or more first ultrasonic signal parameters and one or more second ultrasonic signal parameters may include frequency, amplitude, phase, and / or attenuation coefficient. According to some examples, capturing the first and second ultrasonic signals may involve controlling an ultrasonic sensor system to emit ultrasonic waves according to each of a plurality of modes. Each of these modes may correspond to a different combination of ultrasonic sensor system parameters. Brief description of the attached diagram

[0033] Details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from this description, the drawings, and the claims. It should be noted that the relative dimensions of the following drawings may not be drawn to scale. Similar reference numerals and designations in the various drawings indicate similar elements.

[0034] Figure 1 This is a block diagram illustrating example components of a device implemented according to some of the disclosed methods.

[0035] Figure 2 Example components of a device based on some of the disclosed implementations are shown.

[0036] Figure 3 It is a flowchart that provides operational examples based on some of the disclosed methods.

[0037] Figure 4 An example of a data structure is shown, which can be used to determine one or more fingerprint sensor parameters based at least in part on temperature data from an ultrasonic sensor system.

[0038] Figure 5 It is a graphical representation of an example A-line signal.

[0039] Figure 6Examples are shown of how the frequency of the received A-line signal varies depending on the pattern and the body temperature of the person from whose body parts (e.g., fingers, forehead, wrist, etc.) are obtained.

[0040] Figure 7 This example illustrates how the amplitude of the received A-line signal varies depending on the pattern and body temperature.

[0041] Figure 8 An example illustrating how the phase of the received A-line signal changes depending on the pattern and body temperature.

[0042] Figure 9 This illustrates an example of how the attenuation coefficient corresponding to the received A-line signal varies depending on the pattern and body temperature.

[0043] Figure 10A , 10B Figures 10C and 10D illustrate examples of graphical user interfaces (GUIs) that may be rendered during the implementation of method 300, based on some examples.

[0044] Figure 11A , 11B Figures 11C and 11D show examples of GUIs that can be presented during a user calibration process, based on some examples.

[0045] Figure 12 Another example of a GUI that can be presented in some implementations is shown.

[0046] Figure 13 A representative description of various aspects of a 4×4 pixel array of sensor pixels used in an ultrasonic sensor system is presented.

[0047] Detailed description

[0048] The following description is directed to certain implementations in order to illustrate the inventive aspects of this disclosure. However, those skilled in the art will readily recognize that the teachings herein can be applied in many different ways. The described implementations can be implemented in any device, apparatus, or system, including biometric systems as disclosed herein. Furthermore, it is contemplated that the described implementations can be included in or associated with a variety of electronic devices, such as, but not limited to: mobile phones, Internet-enabled multimedia cellular phones, mobile TV receivers, wireless devices, smartphones, smart cards, wearable devices (such as bracelets, armbands, wristbands, rings, headbands, patches, etc.). Devices, personal data assistants (PDAs), wireless email receivers, handheld or portable computers, netbooks, notebooks, smartbooks, tablets, printers, copiers, scanners, fax equipment, GPS receivers / navigators, cameras, digital multimedia players (such as MP3 players), camcorders, game consoles, wristwatches, clocks, calculators, television monitors, flat panel displays, electronic reading devices (e.g., e-readers), mobile health devices, computer monitors, automotive displays (including odometer and speedometer displays), cockpit controls and / or displays, camera video displays (such as rearview camera displays in vehicles), electronic photographs, electronic billboards or signs, projectors, building structures, microwave ovens, refrigerators, stereo systems, cassette recorders or players, DVD players, CD players, VCRs, radios, portable storage chips, washing machines, dryers, washer / dryer units, parking timers, packages (such as in electromechanical systems (EMS) applications, including microelectromechanical systems (MEMS) applications, and non-EMS applications), aesthetic structures (such as image displays on a piece of jewelry or clothing), and various EMS devices. The teachings herein can also be applied to applications such as, but not limited to, electronic switching devices, radio frequency filters, sensors, accelerometers, gyroscopes, motion sensing devices, magnetometers, inertial components for consumer electronic devices, parts for consumer electronic products, steering wheels or other automotive parts, varactor tubes, liquid crystal devices, electrophoresis equipment, drive systems, manufacturing processes, and electronic testing equipment. Therefore, these teachings are not intended to be limited to the implementations depicted in the accompanying drawings, but have broad applicability, as will be apparent to those skilled in the art.

[0049] The COVID-19 pandemic has increased interest in convenient ways to measure body temperature. In many instances, people may want to measure their temperature when they are not at home and when a thermometer is unavailable. Many people dislike carrying around a thermometer or thermal camera. Some newly deployed smartphones include temperature sensors. However, adding temperature sensors to smartphones increases costs.

[0050] Some of the disclosed devices are capable of measuring or estimating a user's body temperature via an ultrasonic sensor system (such as an ultrasonic fingerprint sensor system). In some examples, the estimation of the user's body temperature may be based at least in part on a comparison of currently acquired ultrasonic signal parameters, previously captured ultrasonic signal parameter data, and previously captured temperature data corresponding to the previously captured ultrasonic signal parameter data.

[0051] Specific implementations of the subject matter described in this disclosure can achieve one or more of the following potential advantages. In some instances, the device (e.g., a smartphone) may not require new hardware to estimate the user's body temperature. Instead, some such implementations may include previously deployed ultrasonic fingerprint sensor hardware configured to provide fingerprint authentication functionality. In some instances, an ultrasonic fingerprint sensor system may be deployed in a smartphone. However, the control system of the device (e.g., a smartphone) can be upgraded and configured to measure or estimate the user's body temperature via the ultrasonic fingerprint sensor system. Such implementations avoid the higher cost of including a temperature sensor configured to measure the user's body temperature in the device.

[0052] According to some examples, an ultrasonic sensor system may include a piezoelectric layer, electrodes near a first side of the piezoelectric layer, and an array of ultrasonic sensor pixels near a second side of the piezoelectric layer. In some such examples, ultrasonic signals used to estimate a person's temperature may be received via the electrodes. Such implementations are potentially advantageous for various reasons. One such potential advantage is that a relatively high signal-to-noise ratio may be possible if the ultrasonic signal is received via the electrodes rather than via the ultrasonic sensor pixel array. Furthermore, implementations where the ultrasonic signal is received via the electrodes rather than via the ultrasonic sensor pixel array can be relatively fast, use relatively less power, and can operate at a relatively low cost.

[0053] Figure 1 This is a block diagram illustrating example components of a device according to some of the disclosed implementations. In this example, device 101 includes an ultrasonic sensor system 102, a control system 106, and a cover 108. In some implementations, device 101 may include an interface system 104 and / or a display system 110.

[0054] According to this example, the ultrasonic sensor system 102 is or includes an ultrasonic fingerprint sensor. In this example, the ultrasonic sensor system 102 includes a temperature sensor 107 configured to determine the temperature of the ultrasonic sensor system and provide ultrasonic sensor system temperature data indicating the temperature of the ultrasonic sensor system to the control system 106. Some alternative examples may not include a temperature sensor configured to determine the temperature of the ultrasonic sensor system. In some examples, as suggested by the dashed lines within the ultrasonic sensor system 102, the ultrasonic sensor system 102 may include an ultrasonic receiver 103 and a separate ultrasonic transmitter 105. In some such examples, the ultrasonic transmitter 105 may include an ultrasonic plane wave generator.

[0055] However, this document discloses various examples of ultrasonic fingerprint sensors, some of which may include a separate ultrasonic transmitter 105, while others may not. Although... Figure 1While shown as separate elements, in some implementations, the ultrasonic receiver 103 and ultrasonic transmitter 105 may be combined in an ultrasonic transceiver system. For example, in some implementations, the ultrasonic sensor system 102 may include a piezoelectric receiver layer, such as a polyvinylidene fluoride (PVDF) polymer layer or a polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) copolymer layer. In some implementations, a single piezoelectric layer may be used as an ultrasonic transmitter. In some implementations, a single piezoelectric layer may be used as both a transmitter and a receiver. In some implementations including a piezoelectric layer, other piezoelectric materials, such as aluminum nitride (AlN) or lead zirconate titanate (PZT), may be used in the piezoelectric layer. In some examples, the ultrasonic sensor system 102 may include an array of ultrasonic transducer elements, such as a piezoelectric micromechanical ultrasonic transducer (PMUT) array, a capacitive micromechanical ultrasonic transducer (CMUT) array, etc. In some such examples, PMUT elements in a single-layer PMUT array or CMUT elements in a single-layer CMUT array may be used as an ultrasonic transmitter along with an ultrasonic receiver.

[0056] The data received from the ultrasonic sensor system 102 may sometimes be referred to herein as “ultrasonic image data,” “image data,” etc., although the data is typically received from the ultrasonic sensor system in the form of electrical signals. Accordingly, without additional processing, such image data may not be perceptible to humans as an image.

[0057] Control system 106 may include one or more general-purpose single-chip or multi-chip processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or combinations thereof. According to some examples, control system 106 may include dedicated components for controlling ultrasonic sensor system 102. Control system 106 may also include one or more memory devices (and / or be configured to communicate with one or more memory devices), such as one or more random access memory (RAM) devices, read-only memory (ROM) devices, etc. Accordingly, device 101 may have a memory system including one or more memory devices, although the memory system in Figure 1 Not shown. The control system 106 may be configured to receive and process data from the ultrasonic sensor system 102. If the device 101 includes a separate ultrasonic transmitter 105, the control system 106 may be configured to control the ultrasonic transmitter 105. In some implementations, the functionality of the control system 106 may be partitioned among one or more controllers or processors, such as between a dedicated sensor controller and an application processor of the mobile device.

[0058] Some implementations of device 101 may include interface system 104. In some examples, interface system 104 may include a wireless interface system. In some implementations, interface system 104 may include a user interface system, one or more network interfaces, one or more interfaces between control system 106 and memory system, and / or one or more interfaces between control system 106 and one or more external device interfaces (e.g., ports or application processors).

[0059] Interface system 104 may be configured to provide communication between components of device 101 (which may include wired or wireless communication, electrical communication, radio communication, etc.). In some such examples, interface system 104 may be configured to provide communication between control system 106 and ultrasonic sensor system 102. According to some such examples, interface system 104 may couple at least a portion of control system 106 to ultrasonic sensor system 102, for example, via a conductive material (e.g., via conductive metal cables or traces). If device 101 includes ultrasonic transmitter 105 separate from ultrasonic receiver 103, interface system 104 may be configured to provide communication between at least a portion of control system 106 and ultrasonic transmitter 105. According to some examples, interface system 104 may be configured to provide communication between device 101 and other devices and / or humans. In some such examples, interface system 104 may include one or more user interfaces. In some examples, interface system 104 may include one or more network interfaces and / or one or more external device interfaces (such as one or more Universal Serial Bus (USB) interfaces or Serial Peripheral Interface (SPI)). In some implementations, device 101 may include a memory system. In some examples, interface system 104 may include at least one interface between control system 106 and memory system.

[0060] According to this example, device 101 includes a cover 108. The cover may or may not be made of a transparent material, such as glass, depending on the specific implementation. Cover 108 may be formed of any suitable material (such as glass, hard plastic, etc.) for a specific implementation. If cover 108 covers a display, cover 108 is preferably formed of a transparent material. In some implementations, at least a portion of cover 108 may not cover the display. According to some such examples, at least a portion of ultrasonic sensor system 102 may reside on the side or back of a device including ultrasonic sensor system 102, such as the side or back of a mobile device (such as a smartphone). In some such implementations, at least a portion of cover 108 may be optically opaque. In some such examples, at least a portion of cover 108 may be formed of metal, opaque plastic, ceramic material, etc.

[0061] In some implementations, device 101 may include display system 110. For example, device 101 may include layers of displays, which may be referred to herein as a “display stack.” In some examples, display system 110 may be or may include a light-emitting diode (LED) display, such as an organic light-emitting diode (OLED) display.

[0062] Device 101 can be used in a variety of different contexts, some of which are disclosed herein. For example, in some implementations, a mobile device may include at least a portion of device 101. In some implementations, a wearable device may include at least a portion of device 101. For example, a wearable device may be a wristband, armband, wrist strap, ring, headband, or patch. In some implementations, control system 106 may reside in more than one device. For example, a portion of control system 106 may reside in a wearable device, while another portion of control system 106 may reside in another device (such as a mobile device (e.g., a smartphone)). In some such examples, interface system 104 may also reside in more than one device.

[0063] Figure 2 Example components of an apparatus according to some of the disclosed implementations are shown. As with other disclosed implementations, the types, numbers, and arrangements of the elements, as well as the dimensions of the elements, are merely examples. According to this example, apparatus 101 is configured to perform at least some of the methods disclosed herein. According to this implementation, apparatus 101 has an ultrasonic sensor system 102, which includes a piezoelectric layer 208, an electrode layer 210 on one side of the piezoelectric layer 208, and a sensor pixel array 206 on a second (and opposite) side of the piezoelectric layer 208. In this implementation, the piezoelectric layer 208 is an ultrasonic transceiver layer comprising one or more piezoelectric polymers. According to this example, the ultrasonic sensor system 102 includes a temperature sensor 107 configured to determine the temperature of the ultrasonic sensor system 102 and to provide ultrasonic sensor system temperature data indicating the temperature of the ultrasonic sensor system to a control system 106. In some implementations, the temperature sensor 107 may be or may include a temperature sensing electrode. In this example, the temperature sensor 107 is electrically connected to a thin-film transistor (TFT) layer 204, for example, via conductive elements (such as pins).

[0064] According to this example, electrode layer 210 resides between passivation layer 212 and piezoelectric layer 208. In some examples, passivation layer 212 may include an adhesive, such as an epoxy resin film, a polymer layer (such as a polyethylene terephthalate (PET) layer), etc.

[0065] In this example, TFT layer 204 includes a TFT substrate and circuitry for sensor pixel array 206. TFT layer 204 can be a type of metal-oxide-semiconductor field-effect transistor (MOSFET) fabricated by depositing an active semiconductor thin film layer, a dielectric layer, and metal contacts on the TFT substrate. In some examples, the TFT substrate is a non-conductive material, such as glass.

[0066] In this example, device 101 includes a display system 110, which in this instance includes an OLED display. Here, the OLED display is attached to the TFT layer 204 via an adhesive layer 202.

[0067] According to this implementation, the TFT layer 204, the sensor pixel array 206, and the electrodes are electrically coupled to at least a portion of the control system 106 and one side of the ultrasonic transceiver layer 101 via a portion of the interface system 104, which in this example includes conductive material and flexible printed circuit (FPC).

[0068] In this example, device 101 is configured to perform at least some of the methods disclosed herein. In this example, control system 106 is configured to control ultrasonic sensor layer 102 to emit one or more ultrasonic waves 213. According to this example, the ultrasonic waves 213 are emitted through TFT layer 204, OLED display, and cover 108. According to this example, the reflection 214 of the ultrasonic waves 213 is caused by the acoustic impedance contrast at (or near) the interface 215 between the outer surface of cover 108 and anything in contact with the outer surface (which can be air or the surface of a target object, such as ridges and valleys of a fingerprint, etc.). (As used herein, the term "finger" can refer to any finger, including the thumb. Accordingly, a thumbprint will be considered a type of "fingerprint.")

[0069] According to some examples, the reflection 214 of the ultrasound waves 213 can be used to estimate the body temperature of a person whose finger is on the outer surface of device 101 (e.g., on cover 108). In some such examples, the reflection 214 can be detected by electrode layer 210. The corresponding ultrasound signal can be provided to control system 106. In some such implementations, the reflection 214 corresponding to the cover / air interface can be detected by electrode layer 210, and the corresponding background ultrasound signal can be provided to control system 106. In some such implementations, the ultrasound signal used by control system 106 for fingerprint-based authentication can be based on the reflections 214 from the cover / finger interface, which are detected by sensor pixel array 206.

[0070] Figure 3 It is a flowchart providing examples of operations based on some of the disclosed methods. For example, Figure 3 The frame can be made of Figure 1 or Figure 2 The apparatus 101 or similar apparatus performs the operation. As with other methods disclosed herein, Figure 3 The methods outlined herein may include more or fewer boxes than indicated. For example, some implementations may omit box 305. Furthermore, the boxes in the methods disclosed herein are not necessarily executed in the indicated order. In some instances, one or more boxes may be executed concurrently.

[0071] In this example, box 305 relates to receiving ultrasonic sensor system temperature data from a temperature sensor configured to determine the ultrasonic sensor system temperature. In this example, the ultrasonic sensor system temperature data indicates the ultrasonic sensor system temperature, for example, Figure 1 or Figure 2 The temperature of the ultrasonic sensor system 102. For example, block 305 may relate to... Figure 1 or Figure 2 The control system 106 receives temperature data from the ultrasonic sensor system from the temperature sensor 107.

[0072] In some examples, method 300 involves determining at least one new ultrasonic fingerprint sensor parameter based at least in part on ultrasonic sensor system temperature data. In some such examples, method 300 may involve determining at least one new ultrasonic fingerprint sensor parameter when the ultrasonic sensor system temperature data indicates that the ultrasonic sensor system temperature has changed by more than a threshold amount (e.g., 3 degrees Celsius, 4 degrees Celsius, 5 degrees Celsius, etc.). The at least one new ultrasonic fingerprint sensor parameter may, for example, include a distance gating delay, the frequency of the emitted ultrasonic wave, or a bias voltage. In some instances, determining at least one new ultrasonic fingerprint sensor parameter may involve obtaining at least one new ultrasonic fingerprint sensor parameter from a temperature-corresponding portion of a data structure. The data structure may be or may include a lookup table. For example, method 300 may involve the control system querying a data structure that includes temperature data and one or more corresponding ultrasonic fingerprint sensor parameters.

[0073] Figure 4 An example data structure is shown that can be used, at least in part, to determine one or more fingerprint sensor parameters based on temperature data from an ultrasonic sensor system. In this example, data structure 405 includes fingerprint sensor parameters and the corresponding temperature in degrees Celsius. According to this example, the fingerprint sensor parameters include frequency, range gating delay (RGD), and bias voltage. RGD may, for example, correspond to the time interval between the emission of ultrasonic waves (or the time when a voltage is applied to cause ultrasonic wave emission) and the start of a time window during which the reflected ultrasonic waves are sampled; this time window may be referred to as a range gating window or RGW. In this example, data structure 405 is a lookup table (LUT).

[0074] In some examples, method 300 may involve querying a data structure (such as data structure 405) and determining one or more ultrasonic fingerprint sensor parameters corresponding to the temperature determined in block 305. In some examples, the data structure may include a transient temperature value and one or more types of corresponding ultrasonic fingerprint sensor parameters. Some implementations involve determining ultrasonic fingerprint sensor parameters for the corresponding transient temperature value.

[0075] return Figure 3 According to this implementation, block 310 relates to capturing a first ultrasonic signal via an ultrasonic sensor system. In some examples, in block 310, Figure 1 or Figure 2 The control system 106 can control the ultrasonic sensor system 102 to capture a first ultrasonic signal. In this example, the first ultrasonic signal corresponds to a reflection from the cover / air interface of the device including the ultrasonic sensor system. As used herein, the word “first” does not necessarily have a temporal meaning. For example, the phrase “first ultrasonic signal” does not necessarily mean (and generally does not mean) that the first ultrasonic signal was previously captured by the ultrasonic sensor system. Instead, terms such as “first,” “second,” etc., as used herein, are primarily (and in some instances simply) intended to identify a particular feature, or a type of feature, and / or to distinguish features from one another.

[0076] In some examples, capturing the first ultrasonic signal may involve controlling an ultrasonic sensor system to emit ultrasonic waves according to each of a plurality of modes. In some implementations, each of these modes may correspond to a different combination of ultrasonic sensor system parameters. Some examples of these modes are described below.

[0077] According to some implementations, a first ultrasonic signal corresponding to reflections from the cover / air interface is used to determine a set of BG ultrasonic image data corresponding to “background” (BG) noise (e.g., for multiple modes). The ultrasonic image data corresponding to the BG noise can be stored in memory and subsequently subtracted from the ultrasonic image data obtained through the target object on the surface in order to increase the signal-to-noise ratio of the resulting ultrasonic image data.

[0078] Some examples may involve (e.g., a user interface system controlled by a control system (such as control system 106)) (e.g., Figure 1 The user interface system section of interface system 104 provides one or more user prompts. Some examples are shown below. Figure 10A The following is illustrated and described in the text. Depending on some implementations, the user interface system may include a display stack, which may be... Figure 1The components of the display system 110. In some implementations, the cover of the device including the ultrasonic sensor system may be a cover glass. In some such implementations, at least a portion of the display stack may reside between the cover glass and the ultrasonic sensor system.

[0079] In this example, box 315 relates to determining one or more first ultrasound signal parameters of a first ultrasound signal. In some instances, in box 315, Figure 1 or Figure 2 The control system 106 can determine first ultrasonic signal parameters. According to some examples, the first ultrasonic signal parameters may include the frequency content, amplitude, and / or phase of the first ultrasonic signal. In some implementations, the first ultrasonic signal parameters may include an attenuation coefficient corresponding to the first ultrasonic signal.

[0080] According to this implementation, block 320 relates to capturing a second ultrasonic signal from a target approaching the lid via an ultrasonic sensor system. In some instances, the target may be a finger on the lid. According to this example, the second ultrasonic signal corresponds to a reflection from the lid / target interface. Alternatively or additionally, in some examples, the second ultrasonic signal corresponds to a reflection from within the target object (such as a finger) on the lid.

[0081] In some examples, the second ultrasonic signal may be received by the electrodes of the ultrasonic sensor system (or may have already been received). For example, the second ultrasonic signal may or may have been received via... Figure 2 Electrode 210 or via a similar electrode is captured. According to some such examples, the control system can be configured to cause the piezoelectric layer (such as...) to... by applying a voltage to the electrodes of the same ultrasonic sensor system used to receive ultrasonic signals. Figure 2 The piezoelectric layer 208 emits ultrasonic waves, and these ultrasonic signals correspond to the reflections caused by these emitted ultrasonic waves. Electrodes of the ultrasonic sensor system (such as...) Figure 2 The ultrasound signal received by electrode 210 may be referred to herein as an A-line signal, an example of which is described in reference below. Figure 5 To describe.

[0082] The ultrasonic signal is transmitted via electrodes of the ultrasonic sensor system (such as...) Figure 2 The implementation of electrode 210 is potentially advantageous, at least in part because a relatively high signal-to-noise ratio can exist where the ultrasonic signal is received via the electrode rather than via the ultrasonic sensor pixel array and the corresponding TFT circuitry. Furthermore, the implementation where the ultrasonic signal can be received via the electrode rather than via the ultrasonic sensor pixel array can be relatively fast, use relatively less power, and operate at a relatively low cost. In some implementations, the first ultrasonic signal may also have been received via… Figure 2The signal is captured by electrode 210 or via a similar electrode. However, in an alternative implementation, the first ultrasonic signal and / or the second ultrasonic signal may be received via one or more of the ultrasonic sensor pixels.

[0083] In some examples, capturing a second ultrasonic signal may involve controlling an ultrasonic sensor system to emit ultrasonic waves according to each of a plurality of modes. In some implementations, each of these modes may correspond to a different combination of ultrasonic sensor system parameters. Some examples of these modes are described below.

[0084] In some examples, method 300 may involve controlling a display stack to present a graphical user interface indicating the area of ​​the ultrasonic sensor system. According to some examples, method 300 may involve controlling the display stack to present text, for example, before capturing the first ultrasonic signal and / or during what may be referred to herein as the “user calibration phase,” prompting the user to ensure that no object is on or near the area of ​​the ultrasonic sensor system before capturing the ultrasonic signal corresponding to the reflection from the cover / air interface. The following references... Figure 10A and 11A To describe some examples. In some examples, method 300 may involve controlling a display stack to present text prompting the user to position a body part on the ultrasound sensor system area before capturing a second ultrasound signal and / or during the user calibration phase. The following references... Figure 10C and 11C Let me describe some examples.

[0085] In this example, box 325 relates to determining one or more second ultrasound signal parameters of the second ultrasound signal. In some instances, in box 325, Figure 1 or Figure 2 The control system 106 can determine the parameters of the second ultrasonic signal. According to some examples, the second ultrasonic signal parameters may include the frequency content, amplitude, and / or phase of the second ultrasonic signal. In some implementations, the second ultrasonic signal parameters may include an attenuation coefficient corresponding to the second ultrasonic signal.

[0086] Based on this example, box 330 relates to (e.g., by a control system, such as) Figure 1 The control system 106 estimates the target object temperature based at least in part on one or more first ultrasonic signal parameters, one or more second ultrasonic signal parameters, and the ultrasonic sensor system temperature. In some examples, block 330 may involve (e.g., by a control system, such as...) Figure 1 The control system 106 estimates the body temperature of the target person by its fingers or other body parts (e.g., the forehead, palm, wrist, etc.).

[0087] In some implementations, block 330 may involve (e.g., by a control system, such as control system 106) retrieving previously captured ultrasonic signal parameter data and previously captured temperature data from memory. According to some examples, block 330 may involve estimating the temperature of a target object based at least in part on the previously captured ultrasonic signal parameter data and the previously captured temperature data.

[0088] Previously captured ultrasound signal parameter data may correspond to previously captured temperature data. Some examples are described below. In some implementations, previously captured ultrasound signal parameter data may have already been captured during what may be referred to herein as the “initial phase.” According to some such implementations, the previously captured ultrasound signal parameter data and the previously captured temperature data obtained during the initial phase were not previously captured from the current owner and / or user of the device implementing method 300.

[0089] Instead, during some implementations in the initial stages, the previously captured ultrasonic signal parameter data and previously captured temperature data are captured from others. In some implementations, the previously captured ultrasonic signal parameter data and previously captured temperature data may have been obtained from dozens, hundreds, or thousands of others. In some such implementations, the previously captured ultrasonic signal parameter data and previously captured temperature data may have been obtained before the deployment of a device configured to estimate the target object temperature based at least in part on the ultrasonic signal parameters. In some such implementations, at least some of the previously captured ultrasonic signal parameter data and previously captured temperature data may have been stored in the memory of a device configured to estimate the target object temperature based at least in part on the ultrasonic signal parameters. In some examples, the previously captured ultrasonic signal parameter data and previously captured temperature data may have been captured via multiple devices.

[0090] Based on some examples, previously captured ultrasonic signal parameter data may have been determined based on ultrasonic signals received by an ultrasonic sensor system configured to emit ultrasonic waves according to each of several modes. Each of these modes may correspond to a different combination of ultrasonic sensor system parameters. The set of ultrasonic sensor system parameters corresponding to four modes is shown in Table 1 below.

[0091]

[0092]

[0093] Table 1

[0094] In this example, each of modes 1-4 corresponds to a set of ultrasonic sensor system parameters including frequency, differential voltage, and amplitude gain. According to this example, the ultrasonic sensor system parameters shown in Table 1 are used to control the ultrasonic sensor system to emit ultrasonic waves. The differential voltage and amplitude shown in Table 1 are additional to the baseline or default level used for emitting ultrasonic waves. Other examples may involve more or fewer modes and / or modes with different ultrasonic sensor system parameters.

[0095] According to some implementations, previously captured ultrasonic signal parameter data can be correlated via ultrasonic sensor electrodes (such as...). Figure 2 The electrode 210 shown in the figure receives the A-line signal.

[0096] Figure 5 This is a graphical representation of an example A-line signal. The vertical axis of graph 500 indicates the amplitude in decibels, and the horizontal axis indicates the time in microseconds.

[0097] According to some implementations, the A-line signal can be represented as the sum of an exponentially decaying sine wave. In one such example, the A-line signal can be represented as follows:

[0098]

[0099] In equation 1, f k Indicates frequency, A k Indicates amplitude, Indicates phase, β k The sine wave represents the attenuation coefficient, t represents time, and B represents a constant. In some examples, B can be a value between 1 and 10, such as 4, 5, 6, or 7. The subscript k refers to a specific sine wave, and in some instances, each corresponds to a specific mode.

[0100] Figure 6 , 7 Figures 8 and 9 are examples illustrating how the elements of Equation 1 change depending on the mode and temperature. Figure 6-9 In the diagram, curve 340 corresponds to the first transmission mode (e.g., mode 1 in Table 1), curve 345 corresponds to the second transmission mode (e.g., mode 2 in Table 1), curve 350 corresponds to the third transmission mode (e.g., mode 3 in Table 1), and curve 355 corresponds to the fourth transmission mode (e.g., mode 4 in Table 1).

[0101] Figure 6 This illustrates how the frequency of the received A-line signal varies depending on the pattern and the body temperature of the person from which data is obtained (e.g., fingers, forehead, wrist, etc.). According to some implementations, the ultrasound signal parameter data and temperature data obtained in the initial stage may include data corresponding to… Figure 6The temperature / frequency pairs of the curves and / or temperature / frequency pairs corresponding to other modes. These temperature / frequency pairs can be stored in memory.

[0102] Figure 7 This illustrates an example of how the amplitude of the received A-line signal varies depending on the mode and body temperature. In some implementations, the ultrasound signal parameter data and temperature data obtained in the initial stage may include data corresponding to… Figure 7 The temperature / amplitude pairs of the curve and / or temperature / amplitude pairs corresponding to other modes. These temperature / amplitude pairs can be stored in memory.

[0103] Figure 8 Examples illustrating how the phase of the received A-line signal changes depending on the pattern and body temperature. In some examples, the ultrasound signal parameter data and temperature data obtained in the initial stage may include data corresponding to... Figure 7 The temperature / phase pairs of the curves and / or temperature / phase pairs corresponding to other modes. These temperature / phase pairs can be stored in memory.

[0104] Figure 9 This illustrates an example of how the attenuation coefficient corresponding to the received A-line signal varies with mode and body temperature. Depending on some implementations, the ultrasound signal parameter data and temperature data obtained in the initial stage may include data corresponding to… Figure 6 The temperature / degradation coefficient pairs of the curves and / or temperature / degradation coefficient pairs corresponding to other modes. These temperature / degradation coefficient pairs can be stored in memory.

[0105] Figure 10A , 10B Figures 10C and 10D illustrate examples of graphical user interfaces (GUIs) that can be rendered during the implementation of method 300, based on several examples. Figure 10A In the example shown, GUI 1000 includes a message area 1005 and indicates an ultrasonic sensor system area 1010. In this example, message area 1005 is displaying information and prompts related to the capture of the aforementioned "first ultrasonic signal" via the ultrasonic sensor system. Because the first ultrasonic signal is intended to include a reference or "background" ultrasonic signal corresponding to the reflection from the cover / air interface, message area 1005 includes information to ensure that in implementing... Figure 3 There is no finger or other object on the ultrasonic sensor system area 1010 before, before, or as part of the process of implementing box 310 and / or 305.

[0106] In some implementations, message area 1005 may be a virtual button that a user can interact with, for example, by touching message area 1005 to indicate that no finger or other object is on ultrasound sensor system area 1010. In some such implementations, device 101 may include a touchscreen, for example, a touchscreen overlaid on a display that is displaying GUI 1000. The control system may be configured to interpret a touch in message area 1005 as a response to at least a portion of the text in message area 1005, for example, as an affirmation that no finger or other object is on ultrasound sensor system area 1010.

[0107] Figure 10B This shows an example of text that can be displayed in message area 1005 when device 101 is calibrating an ultrasonic sensor system. The text displayed in message area 1005 can be, for example, in... Figure 3 Box 310 is presented during the acquisition of the background ultrasonic signal corresponding to the reflection from the cover / air interface and / or during the determination of the first ultrasonic signal parameters in box 315. In some examples, the text shown in message area 1005 may be presented in box 305 during the acquisition of ultrasonic sensor system temperature data.

[0108] Figure 10C An example of a text prompt that may be presented in message area 1005 before a second ultrasonic signal corresponding to the cover / target interface is obtained is shown. In this example, the user is prompted to place a finger or other body part on the ultrasonic sensor system area 1010. In some alternative implementations, the text presented in message area 1005 may provide other examples of suitable body parts, such as the user's forehead, wrist, ear, etc. According to some implementations, ultrasonic sensor system area 1010 may be larger than... Figure 10C As indicated in the reference. In some such implementations, the ultrasonic sensor system region 1010 may coexist with half or more of the display area of ​​the device 101. In some examples, a second ultrasonic signal may be captured after the user places a body part on the ultrasonic sensor system region 1010, for example, as indicated in the reference above. Figure 3 As described in box 320. According to some such examples, the second ultrasonic signal may be received by electrodes of an ultrasonic sensor system.

[0109] Figure 10D This example shows text that can be displayed in message area 1005 after boxes 325 and 330 of method 300 have been executed. In this example, the user's estimated body temperature is displayed in message area 1005.

[0110] According to some such implementations, at least some of the previously captured ultrasound signal parameter data and / or previously captured temperature data may have been previously captured from the user (e.g., via a control system) during what may be referred to herein as the “user calibration phase.” In some implementations, during the user calibration phase, the user will be prompted to measure and enter their current body temperature. In some examples of the user calibration phase, background ultrasound signals and ultrasound signals from the user's body parts will also be captured. According to some examples, method 300 may involve controlling a display stack to present text during the user calibration phase to prompt the user to ensure that no object is on or near the area of ​​the ultrasound sensor system before capturing ultrasound signals corresponding to reflections from the cover / air interface.

[0111] Figure 11A , 11B Figures 11C and 11D illustrate examples of graphical user interfaces (GUIs) that can be presented during a user calibration process, based on several examples. Figure 11A In the example shown, GUI 1100 includes a message area 1105 and indicates the ultrasonic sensor system area 1110. In this example, message area 1105 is displaying information and prompts related to capturing a reference or "background" ultrasonic signal corresponding to the reflection from the cover / air interface during the user calibration process. Here, message area 1105 includes a prompt to ensure that no fingers or other objects are on the ultrasonic sensor system area 1110.

[0112] In some implementations, message area 1105 may be a virtual button that a user can interact with, for example, by touching message area 1105 to indicate that no finger or other object is on ultrasound sensor system area 1110. In some such implementations, device 101 may include a touchscreen, for example, a touchscreen overlaid on a display that is displaying GUI 1100. The control system may be configured to interpret a touch in message area 1105 as a response to at least a portion of the text in message area 1105, for example, as an affirmation that no finger or other object is on ultrasound sensor system area 1110.

[0113] Figure 11B Examples of text that may be presented in message area 1105 while device 101 is calibrating the ultrasonic sensor system are shown. The text shown in message area 1105 may be presented, for example, during the user calibration process at a time when a background ultrasonic signal corresponding to the reflection from the cover / air interface is acquired and / or during the determination of ultrasonic signal parameters corresponding to the background ultrasonic signal. In some examples, the text shown in message area 1105 may be presented during the user calibration process at a time when temperature data of the ultrasonic sensor system is acquired.

[0114] Figure 11CAn example of a text prompt that may be presented in message area 1105 before obtaining an ultrasonic signal corresponding to the cover / target interface during the user calibration process is shown. In this example, the user is prompted to place their finger or other body part on ultrasonic sensor system area 1110. In some implementations, ultrasonic sensor system area 1110 may be larger than... Figure 11C As indicated in [the document]. In some examples, after the user places a body part on the ultrasonic sensor system area 1110, ultrasonic signals corresponding to the cover / target interface (and in some implementations, ultrasonic signals within the body part) can be captured. According to some such examples, these ultrasonic signals can be A-line signals received by the electrodes of the ultrasonic sensor system.

[0115] Figure 11D An example of text that may be presented in message area 1125 after the control system has estimated the user's temperature during the user calibration process is shown. In this example, the user's estimated body temperature is presented in message area 1125. According to this example, message area 1125 also includes a text prompt for the user to enter the user's actual body temperature (e.g., as measured by a thermometer) in window 1130. In this implementation, GUI 1120 includes a virtual keypad 1135 that the user can interact with to enter the user's temperature in window 1130. In some implementations, the temperature estimation process may be recalibrated based on user input regarding the user's actual body temperature. The results of the user calibration process may be stored in memory for later use.

[0116] As mentioned elsewhere in this document, according to some examples, an ultrasonic sensor system may include a piezoelectric layer, electrodes proximate a first side of the piezoelectric layer, and an array of ultrasonic sensor pixels proximate a second side of the piezoelectric layer. In some such examples, ultrasonic signals used to estimate a person's temperature may be received via the electrodes. In some implementations, the control system may be configured to perform an authentication process based at least in part on the ultrasonic signals received via the ultrasonic sensor pixel array.

[0117] In some examples, Figure 1 or Figure 2The control system 106 may be configured to receive from the ultrasonic sensor system 102 a signal corresponding to the reflection of ultrasonic waves from a portion of the surface of a target object (such as a finger) on the outer surface of the cover 108. In some examples, the control system 106 may be configured to acquire fingerprint data based on the portion of the reflected ultrasonic waves corresponding to the fingerprint received within a time interval. This time interval may be measured, for example, relative to the time when the ultrasonic waves corresponding to the reflected ultrasonic waves were emitted. Acquiring fingerprint data may, for example, involve extracting fingerprint features from a first signal via the control system 106. According to some examples, fingerprint features may include fingerprint details, key points, and / or sweat pores. In some examples, fingerprint features may include ridge termination information, ridge bifurcation information, short ridge information, ridge flow information, island information, spike information, triangular information, core information, etc.

[0118] In some examples, the control system 106 may be configured to perform an authentication process that is at least partially based on fingerprint features. According to some examples, the control system 106 may be configured to compare fingerprint features with previously acquired features of the target object (such as a finger) (e.g., acquired during a user registration or enrollment process).

[0119] According to some implementations, the user calibration process may continue at least intermittently during the authentication process. According to some such examples, background ultrasound image data (e.g., for multiple modes) and fingerprint ultrasound image data (e.g., for multiple modes) may be captured during the authentication process and used to update user calibration data previously stored in memory during an earlier user calibration process.

[0120] In some implementations, the control system 106 may be configured to extract subepidermal features from the ultrasound signal. In some such implementations, the subepidermal features may include subepidermal layer information corresponding to reflections received within a time interval that correspond to a subepidermal region. According to some implementations, subsequent authentication processes may involve comparing previously obtained subepidermal features (e.g., those obtained during user registration or enrollment processes) with currently obtained subepidermal features.

[0121] For example, subepidermal features may include dermal information corresponding to reflections of a third ultrasound signal or other ultrasound signals. This dermal information may have already been obtained within a certain timeframe. Subsequent authentication processes may be based at least in part on this dermal information. Alternatively or additionally, subepidermal features may include information about other subepidermal layers, such as the papillary layer, reticular layer, subcutaneous tissue, etc., and any blood vessels, lymphatic vessels, sweat glands, hair follicles, dermal papillae, fat lobules, etc., that may be present within such tissue layers.

[0122] In some examples, the control system 106 may be configured to control access to device 101 or to another device, at least in part, based on an authentication process. For example, in some implementations, a mobile device (such as a cellular phone) may include device 101. In some such examples, the control system 106 may be configured to control access to the mobile device, at least in part, based on a subsequent authentication process.

[0123] In some implementations, the Internet of Things (IoT) device may include device 101. For example, in some such implementations, devices intended for use in the home, such as remote control devices (e.g., remote control devices for smart TVs), stoves, ovens, refrigerators, coffee makers, alarm systems, door locks, mailbox / package locks, thermostats, etc., may include device 101. In some such examples, the control system may be configured to control access to the IoT device, at least in part, based on an authentication process.

[0124] In alternative implementations, a vehicle (including, but not limited to, partially or fully autonomous vehicles), a partially or fully autonomous delivery vehicle, a drone, or another device typically used outside a residence may include one or more instances of device 101. In some such examples, the control system may be configured to control access to the vehicle, drone, etc., at least in part based on a subsequent authentication process.

[0125] In some examples, including but not limited to many IoT implementations, a layer of metal, plastic, ceramic, or polymer may be present between the outer surface of device 101 or the outer surface of a device including device 101. In such implementations, sound waves emitted toward and reflected from a finger or other target may need to pass through this metal, plastic, ceramic, or polymer layer. Ultrasonic waves and other sound waves can be successfully emitted through, for example, a metal layer, while some other types of waves (e.g., light waves) cannot. Similarly, ultrasonic waves and other sound waves can be successfully emitted through optically opaque plastic, ceramic, or polymer layers, while some other types of waves (such as light waves) cannot. This feature is another potential advantage of some disclosed implementations compared to devices that rely on optical or capacitive fingerprint sensors.

[0126] According to some examples, the device can be configured to perform a liveness detection process or another type of spoofing detection process. In some instances, spoofing may involve using a finger-like object that forms the fingerprint pattern of a legitimate user on its outer surface, including silicone rubber, polyvinyl acetate (white glue), gelatin, glycerin, etc. In some cases, a hacker may form the fingerprint pattern of a legitimate user on a sleeve or part of a sleeve, which may be placed on or over the hacker's finger. In some implementations, the spoofing detection process may be based at least in part on a sleeve detection process and / or ultrasound signals corresponding to subepidermal features. Some such liveness determinations may involve obtaining a first subepidermal feature from first ultrasound image data at a first time and a second subepidermal feature from second ultrasound image data at a second time. Some examples may involve making a liveness determination based on a change between the first and second subepidermal features. This type of temporal change may correspond, for example, to blood flow within the finger.

[0127] Figure 12 Another example of a GUI that can be presented in some implementations is shown. In this example, GUI 1200 is presented in the context of a fingerprint authentication process. In some instances, GUI 1200 can be presented after the end-user fingerprint registration process. In this example, the control system of device 101 has determined that the object in contact with the ultrasonic sensor system area 1210 is not a finger. Therefore, the control system is controlling the display to present GUI 1200, including a message area 1205 prompting the user to ensure that the physical finger is on the ultrasonic sensor system area 1210 so that device 101 can perform the fingerprint authentication process.

[0128] Figure 13 A 4×4 pixel array for an ultrasonic sensor system is representatively depicted. Each pixel 1334 may be associated, for example, with a local region of piezoelectric sensor material (PSM), a peak detection diode (D1), and a readout transistor (M3); many or all of these elements may be formed on or in a substrate to form pixel circuitry 1336. In practice, the local region of the piezoelectric sensor material of each pixel 1334 can convert the received ultrasonic energy into electrical charge. The peak detection diode D1 can record the maximum amount of charge detected by the local region of the piezoelectric sensor material PSM. Each row of the pixel array 1335 can then be scanned, for example, via a row selection mechanism, a gate driver, or a shift register, and the readout transistor M3 of each column can be triggered to allow the amplitude of the peak charge of each pixel 1334 to be read by additional circuitry (e.g., a multiplexer and an A / D converter). Pixel circuitry 1336 may include one or more TFTs to allow gating, addressing, and resetting of the pixels 1334.

[0129] Each pixel circuit 1336 can provide a small portion of information about the object detected by the ultrasonic sensor system. Although for ease of explanation... Figure 13 The example shown has a relatively coarse resolution, but ultrasonic sensors with resolutions on the order of 500 pixels per inch or higher can be configured with appropriately scaled structures. The detection area of ​​an ultrasonic sensor system can be selected depending on the object to be detected. For example, the detection area can range from approximately 5mm x 5mm for a single finger to approximately 3 inches x 3 inches for four fingers. Smaller and larger areas (including square, rectangular, and non-rectangular geometries) can be appropriately used for the target object.

[0130] As used in this article, the phrase “at least one of” a list of items refers to any combination of those items, including a single member. As an example, “at least one of a, b, or c” is intended to cover: a, b, c, ab, ac, bc, and abc.

[0131] The various descriptive logics, logic blocks, modules, circuits, and algorithmic processes described in conjunction with the implementations disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. This interchangeability between hardware and software has been generally described in terms of its functionality, and is explained in the various descriptive components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0132] Hardware and data processing means for implementing the various descriptive logics, logic blocks, modules, and circuits described in conjunction with the aspects disclosed herein may be implemented or executed using a general-purpose single-chip or multi-chip processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration. In some implementations, specific processes and methods may be executed by a circuit system dedicated to a given function.

[0133] In one or more aspects, the described functionality may be implemented in hardware, digital electronic circuit systems, computer software, firmware (including the structures disclosed herein and their structural equivalents), or any combination thereof. Implementation of the subject matter described herein may also be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a computer storage medium for execution by a data processing apparatus or for controlling the operation of a data processing apparatus.

[0134] If implemented in software, the functions can be stored or transmitted as one or more instructions or codes on or through a computer-readable medium (such as a non-transient medium). The processes of the methods or algorithms disclosed herein can be implemented in a processor-executable software module that can reside on a computer-readable medium. Computer-readable media include both computer storage media and communication media, including any medium that can be implemented to transfer a computer program from one location to another. Storage media can be any available medium accessible to a computer. By way of example and not limitation, non-transient media can include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and is accessible to a computer. Furthermore, any connection may also be appropriately referred to as a computer-readable medium. As used herein, disk and disc include compact discs (CDs), laser discs, optical discs, digital multifunction discs (DVDs), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically and discs reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media. Additionally, the operation of a method or algorithm may reside as one of code and instructions, or any combination or set of code and instructions, on a machine-readable and computer-readable medium that may be incorporated into a computer program product.

[0135] Various modifications to the implementations described in this disclosure may be apparent to those skilled in the art, and the general principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the implementations shown herein, but should be granted the broadest scope consistent with the claims, the principles disclosed herein, and the novel features. The term “exemplary” is used exclusively (if any) herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as superior to or better than other implementations.

[0136] Some features described in this specification in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented separately or in any suitable sub-combination in multiple implementations. Furthermore, although features may be described above as operating in certain combinations and even originally claimed in this way, one or more features from the claimed combination may be removed from that combination in some cases, and the claimed combination may be for sub-combinations or variations thereof.

[0137] Similarly, although the operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring such operations to be performed in the specific order shown or in sequential order, or requiring the execution of all described operations to achieve the desired result. In some environments, multitasking and parallel processing may be advantageous. Furthermore, the separation of the various system components in the implementations described above should not be construed as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, other implementations also fall within the scope of the appended claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve the desired result.

[0138] It will be understood that, unless features in any particular described implementation are explicitly identified as incompatible with each other, or the surrounding context suggests that they are mutually exclusive and not easily combined in a complementary and / or supporting sense, this disclosure generally contemplates and envisions that specific features of those complementary implementations can be selectively combined to provide one or more comprehensive but slightly different technical solutions. Therefore, it will be further appreciated that the above description is given by way of example only and can be modified in detail within the scope of this disclosure.

Claims

1. An apparatus comprising: An ultrasonic sensor system includes a piezoelectric layer, an ultrasonic sensor system electrode near a first side of the piezoelectric layer, and an ultrasonic sensor pixel array near a second side of the piezoelectric layer. A temperature sensor configured to determine the temperature of the ultrasonic sensor system; Cover; and A control system, at least a portion of which is coupled to the ultrasonic sensor system, is configured to: Temperature data of the ultrasonic sensor system is received from the temperature sensor, and the temperature data of the ultrasonic sensor system indicates the temperature of the ultrasonic sensor system. A first ultrasonic signal is captured via the ultrasonic sensor system, the first ultrasonic signal being received by the electrodes of the ultrasonic sensor system and corresponding to a reflection from the cover / air interface; Determine one or more first ultrasound signal parameters of the first ultrasound signal; A second ultrasonic signal from a target approaching the cover is captured via the ultrasonic sensor system, the second ultrasonic signal being received by electrodes of the ultrasonic sensor system and corresponding to a reflection from the cover / target interface; Determine one or more second ultrasound signal parameters of the second ultrasound signal; and The target object temperature is estimated at least in part based on the one or more first ultrasonic signal parameters, the one or more second ultrasonic signal parameters, and the ultrasonic sensor system temperature.

2. The apparatus of claim 1, further comprising a memory, wherein the control system is further configured to retrieve previously captured ultrasonic signal parameter data and previously captured temperature data from the memory, and to estimate the temperature of the target object based at least in part on the previously captured ultrasonic signal parameter data and the previously captured temperature data.

3. The apparatus of claim 2, wherein the target object is a body part of the user of the apparatus, and wherein the previously captured ultrasound signal parameter data and the previously captured temperature data were previously captured from the user and via the control system during the user calibration phase.

4. The apparatus of claim 3, further comprising a user interface system, wherein the control system is further configured to control the user interface system to provide one or more user prompts.

5. The apparatus of claim 4, wherein the user interface system includes a display stack.

6. The apparatus of claim 5, wherein the cover comprises a cover glass, and wherein at least a portion of the display stack resides between the cover glass and the ultrasonic sensor system.

7. The apparatus of claim 5, wherein the control system is further configured to control the display stack to present a graphical user interface indicating the area of ​​the ultrasonic sensor system.

8. The apparatus of claim 7, wherein the control system is configured to control the display stack to display text during the user calibration phase, before the first ultrasonic signal is captured, or both during the user calibration phase and before the first ultrasonic signal is captured, the text prompting the user to ensure that no object is on or near the ultrasonic sensor system area before capturing the ultrasonic signal corresponding to the reflection from the cover / air interface.

9. The apparatus of claim 7, wherein the control system is configured to control the display stack to present text during the user calibration phase, before capturing the second ultrasound signal, or both during the user calibration phase and before capturing the second ultrasound signal, the text prompting the user to position the body part on the ultrasound sensor system area before capturing an ultrasound signal corresponding to a reflection from the cover / body part interface.

10. The apparatus of claim 5, wherein the control system is further configured to control the display stack to present a graphical user interface indicating the user's estimated body temperature.

11. The apparatus of claim 2, wherein the previously captured ultrasound signal parameter data and the previously captured temperature data were not previously captured from a body part of the user who is the target object.

12. The apparatus of claim 11, wherein the previously captured ultrasound signal parameter data and the previously captured temperature data were captured from multiple persons.

13. The apparatus of claim 11, wherein the previously captured ultrasonic signal parameter data and the previously captured temperature data are captured via multiple devices.

14. The apparatus of claim 1, wherein the one or more first ultrasound signal parameters and the one or more second ultrasound signal parameters comprise at least one parameter selected from the group consisting of frequency, amplitude, phase and attenuation coefficient.

15. The apparatus of claim 1, wherein capturing the first ultrasonic signal and the second ultrasonic signal involves controlling the ultrasonic sensor system to emit ultrasonic waves according to each of a plurality of modes, each of the modes corresponding to a different combination of ultrasonic sensor system parameters.

16. The apparatus of claim 1, wherein the control system is configured to perform an authentication process, the authentication process being based at least in part on ultrasonic signals received via the ultrasonic sensor pixel array.

17. The apparatus of claim 1, wherein the control system is configured to cause the piezoelectric layer to emit ultrasonic waves by applying a voltage to the electrodes of the ultrasonic sensor system.

18. The device of claim 1, wherein the cover is optically opaque.

19. The apparatus of claim 1, wherein the second ultrasonic signal further corresponds to a reflection from within the target object.

20. The apparatus of claim 1, wherein the apparatus is integrated into a mobile device.

21. An apparatus comprising: An ultrasonic sensor system includes a piezoelectric layer, an ultrasonic sensor system electrode near a first side of the piezoelectric layer, and an ultrasonic sensor pixel array near a second side of the piezoelectric layer. A temperature sensor configured to determine the temperature of the ultrasonic sensor system; Cover; and Control device, the control device being used for: Temperature data of the ultrasonic sensor system is received from the temperature sensor, and the temperature data of the ultrasonic sensor system indicates the temperature of the ultrasonic sensor system. A first ultrasonic signal is captured via the ultrasonic sensor system, the first ultrasonic signal being received by the electrodes of the ultrasonic sensor system and corresponding to a reflection from the cover / air interface; Determine one or more first ultrasound signal parameters of the first ultrasound signal; A second ultrasonic signal from a target approaching the cover is captured via the ultrasonic sensor system, the second ultrasonic signal being received by electrodes of the ultrasonic sensor system and corresponding to a reflection from the cover / target interface; Determine one or more second ultrasound signal parameters of the second ultrasound signal; and The target object temperature is estimated at least in part based on the one or more first ultrasonic signal parameters, the one or more second ultrasonic signal parameters, and the ultrasonic sensor system temperature.

22. The device of claim 21, further comprising a memory, wherein the control means includes means for performing the following operations: Retrieve previously captured ultrasound signal parameter data and previously captured temperature data from the memory; and The temperature of the target object is estimated at least in part based on the previously captured ultrasonic signal parameter data and the previously captured temperature data.

23. The device of claim 22, wherein the target object is a body part of a user of the device, and wherein the previously captured ultrasound signal parameter data and the previously captured temperature data were previously captured from the user and via the control device during a user calibration phase.

24. The device of claim 21, further comprising a display, wherein the target object is a body part of a user of the device, and wherein the control means comprises a graphical user interface for controlling the display to present an estimated body temperature of the user.

25. A method comprising: Temperature data of an ultrasonic sensor system is received from a temperature sensor configured to determine the ultrasonic sensor system temperature, and the ultrasonic sensor system temperature data indicates the ultrasonic sensor system temperature. A first ultrasonic signal is captured via the ultrasonic sensor system, the first ultrasonic signal corresponding to a reflection from a cover / air interface, the cover / air interface being the interface between air and a cover including the ultrasonic sensor system; Determine one or more first ultrasound signal parameters of the first ultrasound signal; A second ultrasonic signal from a target approaching the cover is captured via the ultrasonic sensor system, the second ultrasonic signal being received by electrodes of the ultrasonic sensor system and corresponding to a reflection from the cover / target interface; Determine one or more second ultrasound signal parameters of the second ultrasound signal; and The target object temperature is estimated at least in part based on the one or more first ultrasonic signal parameters, the one or more second ultrasonic signal parameters, and the ultrasonic sensor system temperature.

26. The method of claim 25, further comprising: Retrieve previously captured ultrasound signal parameter data and previously captured temperature data from memory; as well as The temperature of the target object is estimated at least in part based on the previously captured ultrasonic signal parameter data and the previously captured temperature data.

27. The method of claim 26, wherein the target object is a body part of a user of the device, and wherein the previously captured ultrasound signal parameter data and the previously captured temperature data were previously captured from the user during a user calibration phase.

28. The method of claim 25, wherein the ultrasonic sensor system comprises a piezoelectric layer, an ultrasonic sensor system electrode adjacent to a first side of the piezoelectric layer, and an ultrasonic sensor pixel array adjacent to a second side of the piezoelectric layer, and wherein the first ultrasonic signal is received by the ultrasonic sensor system electrode.

29. The method of claim 28, further comprising performing an authentication process, the authentication process being at least in part based on ultrasonic signals received via the ultrasonic sensor pixel array.

30. The method of claim 28, further comprising causing the piezoelectric layer to emit ultrasonic waves by applying a voltage to the electrodes of the ultrasonic sensor system.

31. The method of claim 25, wherein the one or more first ultrasound signal parameters and the one or more second ultrasound signal parameters comprise at least one parameter selected from the group consisting of frequency, amplitude, phase, and attenuation coefficient.

32. The method of claim 25, wherein capturing the first ultrasonic signal and the second ultrasonic signal involves controlling the ultrasonic sensor system to emit ultrasonic waves according to each of a plurality of modes, each of the modes corresponding to a different combination of ultrasonic sensor system parameters.

33. The method of claim 25, further comprising controlling the display to present a graphical user interface indicating the estimated temperature of the target object.

34. One or more non-transient media on which software is stored, the software including instructions for performing a method, the method comprising: Temperature data of an ultrasonic sensor system is received from a temperature sensor configured to determine the ultrasonic sensor system temperature, and the ultrasonic sensor system temperature data indicates the ultrasonic sensor system temperature. A first ultrasonic signal is captured via the ultrasonic sensor system, the first ultrasonic signal corresponding to a reflection from a cover / air interface, the cover / air interface being the interface between air and a cover including the ultrasonic sensor system; Determine one or more first ultrasound signal parameters of the first ultrasound signal; A second ultrasonic signal from a target approaching the cover is captured via the ultrasonic sensor system, the second ultrasonic signal being received by electrodes of the ultrasonic sensor system and corresponding to a reflection from the cover / target interface; Determine one or more second ultrasound signal parameters of the second ultrasound signal; and The target object temperature is estimated at least in part based on the one or more first ultrasonic signal parameters, the one or more second ultrasonic signal parameters, and the ultrasonic sensor system temperature.

35. The one or more non-transient media as described in claim 34, wherein the method further comprises: Retrieve previously captured ultrasound signal parameter data and previously captured temperature data from memory; as well as The temperature of the target object is estimated at least in part based on the previously captured ultrasonic signal parameter data and the previously captured temperature data.

36. One or more non-transient media as claimed in claim 35, wherein the target object is a body part of a user of the device, and wherein the previously captured ultrasound signal parameter data and the previously captured temperature data were previously captured from the user during a user calibration phase.

37. One or more non-transient media as claimed in claim 34, wherein the ultrasonic sensor system comprises a piezoelectric layer, an ultrasonic sensor system electrode adjacent to a first side of the piezoelectric layer, and an ultrasonic sensor pixel array adjacent to a second side of the piezoelectric layer, and wherein the first ultrasonic signal is received by the ultrasonic sensor system electrode.

38. The one or more non-transient media as claimed in claim 34, wherein the method further comprises controlling a display to present a graphical user interface indicating an estimated target object temperature.

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