CN117419826A - Electronic device with ultrasonic temperature sensor - Google Patents

Abstract

The present disclosure relates to electronic devices having ultrasonic temperature sensors. The present disclosure relates to an electronic device that may include one or more ultrasonic temperature sensors. The ultrasonic temperature sensor may be formed in an opening or cavity in the housing of the electronic device. The ultrasonic temperature sensor may include an ultrasonic transmitter that transmits signals at different ultrasonic frequencies and an ultrasonic receiver that receives the transmitted signals. The phase difference between the received ultrasonic signals may be used to determine the speed of sound of the ambient air and thus calculate the temperature of the ambient air. The ultrasonic transmitters and receivers may include Piezoelectric Micromachined Ultrasonic Transducers (PMUTs). Each transmitter and receiver may be a dedicated transmitter or receiver, or may transmit and receive ultrasound signals. Each receiver may include an array of PMUTs that receive ultrasound signals of different frequencies. The PMUT may be formed on a Complementary Metal Oxide Semiconductor (CMOS).

Description

Electronic device with ultrasonic temperature sensor

The present application claims priority from U.S. patent application Ser. No. 18/304,197, filed on 4 months 20 of 2023, and U.S. provisional patent application Ser. No. 63/390,247, filed on 7 months 18 of 2022, which are hereby incorporated by reference in their entireties.

Technical Field

The present invention relates generally to electronic devices, and more particularly to electronic devices having environmental sensors.

Background

Electronic devices such as laptop computers, cellular telephones, and other equipment are sometimes provided with environmental sensors such as ambient light sensors, image sensors, and microphones. However, incorporating some environmental sensors into electronic devices where space is limited can be difficult.

Disclosure of Invention

The electronic device may be provided with a housing and a temperature sensor located in the housing. The temperature sensor may be an ultrasonic temperature sensor and may include a plurality of ultrasonic transmitters and receivers. The ultrasound transmitter and receiver may be dedicated to transmitting or receiving, or may perform both functions. The ultrasound transmitter and receiver may each include an array of Piezoelectric Micromachined Ultrasound Transducers (PMUTs) that transmit and are sensitive to different ultrasound frequencies. In operation, the ultrasonic transmitter may transmit signals having different ultrasonic frequencies, and the ultrasonic receiver may receive those signals.

The control circuit may determine the ambient temperature based on a phase difference between the received ultrasonic signals. In particular, the phase difference between the received ultrasonic signals may be related to the speed of sound through the ambient air, which is proportional to the ambient temperature, as the density of the air varies with respect to temperature.

The temperature sensor may be formed in a cavity or opening within the housing and, if desired, covered with a mesh or grid. The temperature sensor may include any desired number of transmitters and receivers (e.g., an array of PMUTs), and may have dedicated ultrasound transmitters and receivers or may have PMUTs that both transmit and receive ultrasound signals. Each PMUT may be formed on a Complementary Metal Oxide Semiconductor (CMOS).

Drawings

Fig. 1 is a diagram of an exemplary wearable electronic device, according to an embodiment.

Fig. 2 is a diagram of an exemplary portable device according to an embodiment.

Fig. 3 is a diagram of an exemplary electronic device, according to an embodiment.

Fig. 4A is a side view of an exemplary electronic device having a temperature sensor in a cavity of a housing according to an embodiment.

Fig. 4B is a side view of an exemplary electronic device having a temperature sensor with a transmitting component and a receiving component in separate cavities of a housing, according to an embodiment.

Fig. 5 is a graph of an exemplary relationship between temperature and measured sound velocity according to an embodiment.

Fig. 6 is a graph of an exemplary relationship between air density/barometric pressure and altitude according to an embodiment.

Fig. 7 is a diagram of an exemplary ultrasonic temperature sensor having a transmitter and a receiver according to an embodiment.

Fig. 8A is a graph of an exemplary relationship between multiple transmit frequencies and phases (the number of cycles passed between the transmitter and the receiver) in an ultrasonic temperature sensor according to an embodiment.

Fig. 8B is a graph of an exemplary relationship between multiple transmit frequencies and phase differences in an ultrasonic temperature sensor according to an embodiment.

FIG. 9 is a diagram of an exemplary ultrasonic temperature sensor having multiple transmitters and receivers according to an embodiment.

Fig. 10 is a graph of an exemplary relationship between temperature and phase difference measured by ultrasonic temperature, according to an embodiment.

Fig. 11 is a top view of an exemplary array of piezoelectric micromachined ultrasonic transducers that may be used in an ultrasonic temperature sensor according to an embodiment.

Fig. 12 is a side view of an exemplary piezoelectric micromachined ultrasonic transducer that may be used in an ultrasonic temperature sensor according to an embodiment.

FIG. 13 is a flowchart of exemplary steps used in determining an ambient temperature using an ultrasonic temperature sensor, according to an embodiment.

Detailed Description

Electronic devices are typically carried by a user while the user is performing daily activities. For example, a user may carry an electronic device with him throughout the day during walking, commuting, work, exercise, etc. In some cases, it may be desirable for the user to know the ambient temperature of the air or the temperature of another ambient medium (e.g., water). Although the electronic device may receive information about ambient temperature and weather conditions through various online resources, this information may be inaccurate with respect to the exact location of the user, such as a shaded area (e.g., under a tree or on a mall) or on a surface that may affect the ambient temperature (e.g., grass or asphalt). Thus, one or more temperature sensors may be incorporated into the electronic device to directly measure the ambient temperature.

The temperature sensor may be an ultrasonic temperature sensor that determines the speed of sound through ambient air (or through another surrounding medium). This speed of sound may then be used to determine the temperature of the air or other surrounding medium. In this way, a temperature sensor within the electronic device may take accurate temperature measurements of the environment surrounding the user.

Generally, any suitable electronic device may include a temperature sensor. As shown in fig. 1, a wearable electronic device 10, which may be a wristwatch device, may have a case 12, a display 14, and a wristband 16. The wristwatch may be attached to the wrist of the user via a wristband 16. One or more temperature sensors may be incorporated into the housing 12. For example, the housing 12 may have an opening or cavity 13. The temperature sensor may be formed within the opening or cavity 13. In particular, the opening or cavity 13 may allow ambient air to reach a temperature sensor, which may then determine the temperature of the ambient air. In some embodiments, the openings or cavities 13 may be covered by a mesh, grille, or other covering that allows for the unimpeded passage of air.

Another exemplary device that may include one or more temperature sensors is shown in fig. 2. As shown in fig. 2, a portable device 10, which may be a cellular telephone, tablet computer, or other portable device, has a housing 12 and a display 14. One or more temperature sensors may be incorporated into the housing 12 within the opening or cavity 13.

Although the opening or cavity 13 is shown in fig. 1 and 2 on the side wall of the housing 12 (i.e., between the front face of the housing 12 having the display 14 and the opposite back face of the housing 12), this is merely illustrative. In general, the temperature sensor may be formed anywhere in the device, such as on the front of the device 10 (with the display 14) and/or on the back of the device 10 (opposite the display 14).

Although fig. 1 and 2 illustrate the electronic device 10 as a wristwatch device and/or a cellular telephone device, these examples are merely illustrative. Generally, the electronic device 10 may be any desired device, such as a media player or other handheld or portable electronic device, a wristband device, a pendant device, a headset, a speaker, a smart speaker, an ear bud or earpiece device, a head mounted device such as glasses, goggles, a helmet or other equipment worn on a user's head, or other wearable or miniature device, a navigation device or other accessory, and/or equipment that performs the function of two or more of these devices. An illustrative configuration in which the electronic device 10 is a portable electronic device (such as a cellular telephone, wristwatch, or portable computer) may sometimes be described herein as an example. Regardless of the form factor of the device 10, an exemplary schematic of the device 10 is shown in fig. 3.

As shown in fig. 3, an electronic device, such as electronic device 10, may have a control circuit 112. Control circuitry 112 may include storage and processing circuitry for controlling the operation of device 10. The circuitry 112 may include storage devices such as hard drive storage devices, non-volatile memory (e.g., electrically programmable read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random access memory), and the like. The processing circuitry in the control circuitry 112 may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, graphics processing units, application specific integrated circuits, and other integrated circuits. The software codes may be stored on a memory device in the circuit 112 and run on a processing circuit in the circuit 112 to implement control operations for the device 10 (e.g., data acquisition operations, operations involving adjusting components of the device 10 using control signals, etc.).

The electronic device 10 may include communication circuitry 114, which may include wired and/or wireless communication circuitry. The electronic device 10 may include radio frequency transceiver circuitry, such as cellular telephone transceiver circuitry, wireless local area network transceiver circuitry (e.g., Circuitry), short-range radio-frequency transceiver circuitry that communicates over short distances using ultra-high frequency radio waves (e.g., operating at 2.4GHz +.>Circuitry or other short-range transceiver circuitry), millimeter-wave transceiver circuitry, and/or other wireless communication circuitry.

The device 10 may include an input-output device 116. The input-output device 116 may be used to allow a user to provide user input to the device 10. The input-output device 116 may also be used to gather information about the environment in which the device 10 is operating. Output components in device 116 may allow device 10 to provide output to a user and may be used to communicate with external electrical equipment.

The input-output device 116 may include one or more optional displays, such as display 14. The display 14 may be an organic light emitting diode display or other display having light emitting diodes, a liquid crystal display, a micro LED display, or other display. The display 14 may be touch sensitive (e.g., the display 14 may include a two-dimensional touch sensor for capturing touch input from a user) and/or the display 14 may be touch insensitive.

The input-output device 116 may include a sensor 118. The sensor 118 may include, for example, a three-dimensional sensor (e.g., a three-dimensional image sensor such as a structured light sensor that emits a light beam and that uses a two-dimensional digital image sensor to collect image data for a three-dimensional image from a light spot generated when a target is illuminated by the light beam, a binocular three-dimensional image sensor that collects three-dimensional images with two or more cameras in a binocular imaging arrangement, a three-dimensional lidar (light detection and ranging) sensor, a three-dimensional radio frequency sensor, or other sensor that collects three-dimensional image data), a camera (e.g., an infrared and/or visible light digital image sensor), a gaze tracking sensor (e.g., a gaze tracking system based on an image sensor and, if desired, a light source that emits one or more light beams, the light beam is tracked with an image sensor after reflection from the user's eye), touch sensors, capacitive proximity sensors, light-based (optical) proximity sensors, other proximity sensors, force sensors, sensors such as switch-based contact sensors, gas sensors, pressure sensors, humidity sensors, magnetic sensors (e.g., magnetometer), audio sensors (microphones), ambient light sensors, microphones for gathering voice commands and other audio inputs, sensors configured to gather information about motion, position and/or orientation (e.g., accelerometers, gyroscopes, pressure sensors, compasses, and/or inertial measurement units comprising all or a subset of one or both of these sensors), health sensors (e.g., heart rate sensors, such as photoplethysmographic sensors, electrocardiographic sensors, and perspiration sensors), and/or other sensors that measure various biometric information.

The sensors 118 may also include one or more temperature sensors 120. The temperature sensor 120 may be, for example, an ultrasonic sensor that measures the speed of sound through ambient air. In particular, the temperature sensor 120 may include one or more ultrasonic transmitters and one or more ultrasonic receivers. The ultrasonic transmitter may transmit signals having different ultrasonic frequencies, and the ultrasonic receiver may receive the transmitted signals. Control circuitry in device 10, such as control circuitry 112, may determine a phase difference between signals received by the ultrasound receiver, which may be used to determine the ambient temperature.

If desired, the input-output devices 116 may include other devices 124, such as haptic output devices (e.g., vibrating components), light emitting diodes and other light sources, speakers such as ear speakers for producing audio output, circuitry for receiving wireless power, circuitry for wirelessly transmitting power to other devices, batteries and other energy storage devices (e.g., capacitors), joysticks, buttons, and/or other components.

To house a sensor (such as temperature sensor 120) in device 10, it may be desirable to have an opening or cavity in the housing of device 10. An example of an opening or cavity that may be incorporated into the device housing is shown in fig. 4A.

As shown in fig. 4A, the housing 12 of the device 10 may include an opening/cavity 13. The cavity 13 may be a recessed portion of the housing 12 (i.e., the cavity 30 extends partially through the housing 12), as shown in fig. 4A. Alternatively, the opening 13 may extend entirely through the housing 12. Regardless of whether the cavity/opening 13 extends partially or completely through the housing 12, a temperature sensor (such as temperature sensor 120) may be formed within the cavity/opening 13. The temperature sensor 120 may be, for example, an ultrasonic temperature sensor.

The opening/cavity 13 and the temperature sensor 120 may be covered if desired. As shown in fig. 4A, an optional mesh 15 may cover the temperature sensor 120. Openings in mesh 15 may allow ambient air to reach temperature sensor 120, so temperature sensor 120 may determine the temperature of the ambient air. The mesh 15 may be a passive low pass acoustic filter that allows ambient air to reach the temperature sensor 120. Although fig. 4 shows mesh 15 covering temperature sensor 120, any desired material (such as a grill or other material that allows for unimpeded passage of air) may cover temperature sensor 120.

In some examples, it may be desirable to increase the amount of air circulated and reaching the temperature sensor 120. Thus, the temperature sensor 120 may be formed in the opening/cavity 13 with a speaker, fan, pump, or other component that may circulate air into the cavity 13. In this way, the temperature sensor 120 may obtain an accurate measurement of the ambient air temperature.

In general, any number of openings and/or cavities may be formed in the housing 12, and the electronic device 10 may include any desired number of temperature sensors. One or more temperature sensors and associated openings/cavities may be formed on the front, back, and/or side walls of the device 10. In addition, although fig. 4A shows a single temperature sensor in a single cavity, the temperature sensor may have a transmitter and a receiver formed in separate cavities. An example of such an arrangement is shown in fig. 4B.

As shown in FIG. 4B, the housing 12 may have two housing portions, 12-1 and 12-2. In each housing part there may be separate cavities, which cavities may be covered by acoustic filters 15-1 and 15-2, respectively. The ultrasonic transmitter 20 may be formed in a cavity in the housing portion 12-1 and the ultrasonic receiver 22 may be formed in the housing portion 12-2. However, the positioning of temperature sensor 120 (or portions of temperature sensor 120, such as ultrasonic transmitter 20 and ultrasonic receiver 22) in one or more cavities in housing 12 is merely illustrative. In some examples, the temperature sensor may include an ultrasonic transmitter and receiver, and one or both of the ultrasonic transmitter and receiver may be positioned on an exterior surface of the device 10 (e.g., on an exterior surface of the housing 12). Regardless of where the temperature sensors are included in the device 10, they may be ultrasonic temperature sensors that measure the temperature of ambient air through a correlation between ambient temperature and the speed of sound through the air. An exemplary relationship between sound velocity and temperature is shown in fig. 5.

Curves 16 and 18 of fig. 5 are exemplary relationships between sound velocity (m/s) in air and air temperature (K) at 100% humidity and 0% humidity, respectively. As shown in curve 18, at 0% humidity, from 250K to 330K, there is a linear (or substantially linear) relationship between temperature and speed of sound. Although this linear relationship does not hold for high temperatures (e.g., over 315K) at 100% humidity, the relationship is linear for most temperature ranges. If desired, dispersion at higher temperatures can be explained by approximation of humidity from an online weather service. Alternatively or additionally, the electronic device 10 may include a pressure sensor and/or a humidity sensor to determine the ambient humidity, which may then be used by control circuitry in the device 10 to correct the ambient temperature measurement. An example of compensation for differences in air density/barometric pressure is shown in fig. 6.

Curve 19 of fig. 6 is an exemplary relationship between air density and altitude, while curve 21 of fig. 6 is an exemplary relationship between barometric pressure and altitude. As shown in fig. 6, both the curves 19 and 21 decrease with increasing altitude. Thus, when the electronic device 10 is brought to a higher altitude, the air density and barometric pressure will decrease, affecting the speed of sound through the air. In particular, at higher altitudes, the air density will be lower, and therefore the speed of sound through the air will be lower at typical humidity levels. To compensate for this variation, a pressure sensor in the device 10 may be used to measure barometric pressure (or other sensors within the device 10 may be used to determine barometric pressure/altitude), which may be correlated to altitude and air density, as shown in fig. 6. Once the air density is known, the control circuitry in the device 10 can correct the sound speed based ambient temperature measurement according to fig. 5. For example, if the device 10 is at a high altitude, the control circuit may correct the ambient temperature measurement upward according to the relationship in fig. 5 and 6 to compensate for the reduced speed of sound through the lower density air.

Thus, a temperature sensor (such as temperature sensor 120) may determine the ambient temperature by a relationship with the speed of sound through ambient air. An exemplary ultrasonic temperature sensor that can determine the ambient temperature from the speed of sound is shown in fig. 7.

As shown in fig. 7, a temperature sensor (such as temperature sensor 120) may include an ultrasonic transmitter 20 and an ultrasonic receiver 22. The ultrasound transmitter 20 may transmit one or more ultrasound frequencies between 1MHz and 3 MHz. As shown in fig. 7, the ultrasound transmitter 20 may transmit a first signal 24 and a second signal 26. The first signal 24 and the second signal 26 may have different ultrasonic frequencies. As an example, the first signal 24 may have a frequency of at least 1MHz, at least 1.2MHz, or at least 1.23 MHz. The second signal 26 may have a frequency between 2MHz and 3MHz or other desired frequency. In general, the first signal 24 and the second signal 26 may have any desired ultrasonic frequency.

Ultrasonic receiver 22 may be separated from ultrasonic transmitter 20 by a distance d and first signal 24 and second signal 26 may be detected when they reach ultrasonic receiver 22. The transmitter 20 and receiver 22 may be separated by any desired distance d, such as less than 20mm, less than 15mm, between 10mm and 15mm, or less than 10mm. In general, the speed of sound may be determined from the distance d, the frequency emitted by the ultrasonic emitter 20, and the number of wavelengths (i.e., the number of periods) between the ultrasonic emitter 20 and the ultrasonic receiver 22. However, the number of cycles between the ultrasonic emitter 20 and the ultrasonic receiver 22 may be difficult to directly measure. Thus, the phase difference between the first signal 24 and the second signal 26 can be used To determine the speed of sound.

In particular, distance d may be related to wavenumber n according to equation 1:

where lambda is the wavelength of the signal emitted by the emitter 20, andis the radian phase change of the corresponding signal at the receiver 22. By using equation 1, the relationship between sound speed and ambient temperature, the relationship between sound speed and the number of wavelengths passing a given distance at a given frequency, and known parameters of signals 24 and 26 (e.g., the frequency of the signals), the phase between signals 24 and 26 ∈ ->The difference in (c) may be related to the ambient temperature. In this way, the ultrasonic temperature sensor 120 may be used to determine the ambient temperature.

Although fig. 7 shows a single ultrasonic transmitter and a single ultrasonic receiver transmitting two signals of different ultrasonic frequencies, this is merely illustrative. In general, the temperature sensor may include any desired number of ultrasonic transmitters and receivers. In addition, the temperature sensor may emit and detect any desired number of ultrasonic signals at different frequencies. Exemplary graphs showing the number of elapsed periods and the phase differences of the plurality of frequencies are shown in fig. 8A and 8B.

As shown in fig. 8A, a plurality of signals may be transmitted by an ultrasound transmitter, such as transmitter 20. The transmitted signals may be pulsed or continuous and different frequencies may be transmitted simultaneously or sequentially. Each signal may be transmitted at a different frequency, such as a frequency between 1MHz and 3 MHz. Because of the different frequencies, each signal may take a different number of cycles (i.e., wavelengths) to reach the ultrasound receiver. Each signal is represented by one of the points 28 of fig. 8A. As shown, higher frequency signals may take more cycles to reach the ultrasound receiver, while lower frequency signals may take less cycles to reach the ultrasound receiver. The relationship between frequency and the period elapsed between transmission and reception may be given by line (or curve) 30.

Although the speed of sound (and thus the ambient temperature) may be determined from the number of cycles that have passed between transmission and reception, this may be difficult to measure directly. Instead, the phase difference between each received signal may be determined. An exemplary relationship between frequency and phase difference is shown in fig. 8B.

As shown in fig. 8B, the phase difference between transmission and reception at each frequency may be plotted for each signal 28. The relationship between these phase differences can be found. In particular, a curve (such as curve 32) may be fitted to each point (corresponding to each signal 28). Curve 32 may provide a best fit (or other desired) function between frequency and phase difference. After obtaining curve 32, the speed of sound may be calculated from a set of equations including equation 1 for each frequency, the speed of sound versus the number of wavelengths in a given distance at a given frequency, and known parameters of the ultrasound signal. In this way, the ambient temperature can be measured.

As previously described, the ultrasonic transmitter may transmit a plurality of ultrasonic frequencies, which may then be received by the ultrasonic receiver. In some embodiments, it may be desirable to have multiple ultrasonic transmitters each transmitting signals at one or more ultrasonic frequencies and multiple ultrasonic receivers receiving those signals. An example of a temperature sensor having multiple ultrasonic transmitters and multiple ultrasonic receivers is shown in fig. 9.

As shown in fig. 9, the temperature sensor 120 may include a plurality of ultrasonic transmitters 20 and a plurality of ultrasonic receivers 22. Each ultrasonic emitter 20 may emit a plurality of signals that may be detected by ultrasonic receiver 22, as indicated by the lines from each ultrasonic emitter 20. If desired, each ultrasound transmitter 20 may comprise an array of individual ultrasound transmitters, and each ultrasound receiver 22 may comprise an array of individual ultrasound receivers. In some examples, each ultrasonic emitter 20 (e.g., an array of ultrasonic emitters) may emit multiple signals at the same frequency, or may emit multiple signals at different frequencies. Alternatively or additionally, each ultrasound transmitter 20 (e.g., an array of ultrasound transmitters) may transmit signals at a different frequency. In this way, signals having different frequencies can be transmitted and detected, allowing the phase difference between the detected signals to be determined and the ambient temperature to be calculated.

The example of fig. 9 shows an arrangement in a temperature sensor with three arrays of ultrasonic transmitters and three arrays of ultrasonic receivers. However, this is merely illustrative. Any number of desired ultrasound transmitters and receivers may be used. For example, the temperature sensor may have five arrays of ultrasonic transmitters and five arrays of ultrasonic receivers, one ultrasonic transmitter and one ultrasonic receiver, or any other desired number of transmitters and receivers. All transmitters may be formed in a shared plane and all receivers may be formed in a shared plane, or these components may be formed in different planes. The transmitter and receiver may face each other or may be adjacent to each other. If desired, the transmitter may be formed on a first shared semiconductor die and the receiver may be formed on a second shared semiconductor die. Alternatively, the transmitter and receiver may be formed on a single semiconductor die. In some examples, the temperature sensor may have a different number of transmitters and receivers, such as three transmitters and five receivers.

By having multiple ultrasound emitter arrays, multiple times of flight can be measured for the same frequency. To detect a temperature change of 0.5 ℃, an ultrasonic temperature sensor may need to measure a change in sound velocity of one thousandth. In addition, one thousandth of a mechanical change (10 microns for a 1cm gap) may be difficult to avoid. By using a plurality of ultrasonic transmitters 20 (which may each comprise an array of individual transmitters) and a plurality of ultrasonic receivers 22 (which may each comprise an array of individual receivers), the speed of sound and the geometric variations of the temperature sensor may be disambiguated. For example, with five transmitter arrays and five receiver arrays, 25 time-of-flight measurements may be made.

Regardless of the number of transmitters and receivers incorporated into the temperature sensor, some transmitters and/or receivers may be selectively deactivated and activated as desired. For example, a temperature sensor may save power by using fewer than all of the transmitters and/or receivers during some measurements. However, this is merely illustrative. Generally, all transmitters and receivers can be used for all temperature measurements if desired.

Although the temperature sensor has been described as having an ultrasonic transmitter (such as ultrasonic transmitter 20) and an ultrasonic receiver (such as ultrasonic receiver 22), the temperature sensor may be an ultrasonic component that both transmits and receives signals if desired. For example, in the example of fig. 9, during some measurements, the component 20 may transmit ultrasonic signals and the component 22 may receive those signals, while during other measurements, the component 22 may transmit ultrasonic signals and the component 20 may receive those signals. In other words, in some embodiments, the directionality of the transmission and reception shown in fig. 9 may be reversed.

Alternatively or additionally, if desired, ultrasound components may be used for both transmission and reception during the same measurement. For example, the component 20 may emit ultrasonic signals that may reflect off of a known surface, such as the housing 12 or other surface in the cavity/opening 13 (fig. 4), and the component 20 may detect the reflected signals. In general, any desired arrangement of ultrasonic components may be used to transmit and detect ultrasonic signals having different frequencies to determine a phase difference between the detected signals. The phase difference may then be used to determine the ambient temperature. An exemplary relationship between the phase difference of the received ultrasonic signals and the ambient temperature is shown in fig. 10.

As shown in FIG. 10, the ambient temperature and the phase difference can be establishedAn exemplary relationship 34 therebetween. In particular, by transmitting a plurality of ultrasonic frequencies and determining the phase difference between these frequencies when detected, the ambient temperature may be determined. In this way, the ultrasonic temperature sensor can determine the ambient temperature by transmitting and detecting a plurality of signals having different ultrasonic frequencies.

An ultrasonic transmitter, such as ultrasonic transmitter 20, and an ultrasonic receiver, such as ultrasonic receiver 22, may be formed from one or more microelectromechanical system (MEMS) sensors, such as Piezoelectric Micromechanical Ultrasonic Transducers (PMUTs). For example, the ultrasound component within the temperature sensor may include one or more PMUT arrays. An example of an ultrasound component comprising a PMUT array is shown in fig. 11.

As shown in fig. 11, the ultrasound component 36 may include a PMUT array. Ultrasound component 36 may be an ultrasound transmitter (such as ultrasound transmitter 20), an ultrasound receiver (such as ultrasound receiver 22), or an ultrasound component that both transmits and receives ultrasound signals. The ultrasound component 36 may include a PMUT 38, a PMUT 40, a PMUT 42, and a PMUT 44, each of which may transmit and/or receive ultrasound signals at different frequencies. PMUTs 38, 40, 42, and 44 may enable ultrasound component 36 to transmit different frequencies, or receive different frequencies transmitted by different ultrasound components or by ultrasound component 36. Each of PMUTs 38, 40, 42, and 44 may transmit and/or receive dedicated ultrasonic frequencies between 1MHz and 3MHz, or may be tunable to transmit and/or receive any desired frequency. Each of PMUT 38, PMUT 40, PMUT 42, and PMUT 44 may be formed on a Complementary Metal Oxide Semiconductor (CMOS). An embodiment of PMUT formation on CMOS is shown in fig. 12.

As shown in fig. 12, PMUT 41 may be formed on CMOS 39. CMOS 39 may include a substrate 43, which may be a semiconductor substrate, such as silicon. A plurality of metal layers 46 interconnected by vias 48 may be formed in layer 45 on substrate 43. Layer 45 may be formed of silicon dioxide or other desired material. Bond pad 50 may be formed on the top surface of layer 45 and may be formed of any desired metal.

PMUT 41 may be formed on top of CMOS 39, more specifically, on top of layer 45. In particular, a metal layer 56 may be formed on top of layer 45. The metal layer 46 may be aluminum or another desired metal. Layer 52 may be formed on metal layer 46 and may include a nitride, such as aluminum nitride or gallium nitride. Alternatively, other materials (such as lithium niobate) may be used to form layer 52.

Another metal layer 58 may be formed on layer 52. The metal layer 58 may be formed of aluminum or another desired metal. In some embodiments, it may be desirable to form metal layer 58 from the same metal as metal layer 56.

Upper layer 60 may overlap metal layer 58 (and also have a portion 54 that overlaps layer 52). The upper layer 60 may be formed of silicon dioxide, silicon nitride, or another desired material.

In general, PMUT 41 may be formed on standard CMOS and may include one or more metal layers used by circuitry within the electronic device to transmit and/or receive desired ultrasonic frequencies. A flowchart of exemplary steps with operating temperature sensors, such as temperature sensors including one or more PMUTs 41, is shown in fig. 13.

As shown in fig. 13, at step 210, a transmitter (such as ultrasonic transmitter 20) may transmit a plurality of signals at an ultrasonic frequency. In general, any desired number of transmitters may be used to transmit any desired number of signals having different frequencies. In some examples, one, three, or five transmitters may be used to transmit two, three, or five different ultrasound frequencies. As an example, the ultrasound frequency may be between 1MHz and 3 MHz.

At step 220, a sensor (such as an ultrasonic receiver 22) may receive the signal. As an example, the sensor may include one or more ultrasonic receivers, such as three receivers or five receivers. In some embodiments, the ultrasound receiver may also transmit ultrasound frequencies, or the ultrasound receiver may be a dedicated receiver.

At step 230, a temperature sensor or control circuit within the device 10 may measure a phase difference between the received signals. In particular, because the received signals have different frequencies, these signals will propagate a different number of wavelengths (periods) between the transmitter and the receiver. Although the number of cycles each signal propagates cannot be measured directly, the receiver or control circuit can determine the phase of the signal incident on the receiver.

At step 240, a temperature sensor or control circuit within device 10 may calculate an ambient temperature based on the phase difference. As previously described, the relationship between phase difference and temperature may be calculated based on equation 1 and known properties of the transmitted and received signals. In this way, an ultrasonic temperature sensor may be used to measure ambient temperature.

Although ultrasonic temperature sensors have been described as measuring ambient temperature by measuring the speed of sound through air, this is merely illustrative. In general, an ultrasonic temperature sensor, such as temperature sensor 120, may be used to measure the temperature of any medium, such as water, other fluids, or other materials external to the electronic device, such as glass. In these alternative implementations, the temperature sensor 120 may be formed in the interior of the electronic device (such as in the cavity 30) or formed outside the electronic device (such as on a surface of a housing of the electronic device (such as the housing 12)).

As described above, one aspect of the present technology is to collect and use information, such as information from an input-output device. The present disclosure contemplates that in some cases, data may be collected that includes personal information that uniquely identifies or may be used to contact or locate a particular person. Such personal information data may include demographic data, location-based data, telephone numbers, email addresses, twitter IDs, home addresses, data or records related to the user's health or fitness level (e.g., vital signal measurements, medication information, exercise information), birth dates, user names, passwords, biometric information, or any other identifying or personal information.

The present disclosure recognizes that the use of such personal information in the disclosed technology may be used to benefit a user. For example, the personal information data may be used to deliver targeted content of greater interest to the user. Thus, the use of such personal information data enables a user to have programmatic control over the delivered content. In addition, the present disclosure contemplates other uses for personal information data that are beneficial to the user. For example, health and fitness data may be used to provide insight into the overall health of a user, or may be used as positive feedback to individuals using technology to pursue health goals.

The present disclosure contemplates that entities responsible for collecting, analyzing, disclosing, transmitting, storing, or otherwise using such personal information data will adhere to established privacy policies and/or privacy practices. In particular, such entities should exercise and adhere to privacy policies and practices that are recognized as meeting or exceeding industry or government requirements for maintaining the privacy and security of personal information data. Such policies should be readily accessible to the user and should be updated as the collection and/or use of the data changes. Personal information from users should be collected for legal and reasonable use by entities and not shared or sold outside of these legal uses. In addition, such collection/sharing should be performed after informed consent is received from the user. In addition, such entities should consider taking any necessary steps to defend and secure access to such personal information data and to ensure that others who have access to personal information data adhere to their privacy policies and procedures. In addition, such entities may subject themselves to third party evaluations to prove compliance with widely accepted privacy policies and practices. In addition, policies and practices should be adjusted to collect and/or access specific types of personal information data and to suit applicable laws and standards including specific considerations of jurisdiction. For example, in the united states, the collection or access of certain health data may be governed by federal and/or state law, such as the health insurance and liability act (HIPAA), while health data in other countries may be subject to other regulations and policies and should be processed accordingly. Thus, different privacy practices should be maintained for different personal data types in each country.

In spite of the foregoing, the present disclosure also contemplates embodiments in which a user selectively prevents use or access to personal information data. That is, the present disclosure contemplates that hardware elements and/or software elements may be provided to prevent or block access to such personal information data. For example, the present technology may be configured to allow a user to choose to participate in the collection of personal information data "opt-in" or "opt-out" during or at any time after the registration service. As another example, the user may choose not to provide a particular type of user data. For another example, the user may choose to limit the length of time that user-specific data is maintained. In addition to providing the "opt-in" and "opt-out" options, the present disclosure also contemplates providing notifications related to accessing or using personal information. For example, the user may be notified that his personal information data will be accessed when an application program ("application") is downloaded, and then be reminded again just before the personal information data is accessed by the application.

Further, it is an object of the present disclosure that personal information data should be managed and processed to minimize the risk of inadvertent or unauthorized access or use. Once the data is no longer needed, risk can be minimized by limiting the data collection and deleting the data. In addition, and when applicable, included in certain health-related applications, the data de-identification may be used to protect the privacy of the user. De-identification may be facilitated by removing a particular identifier (e.g., date of birth, etc.), controlling the amount or characteristics of data stored (e.g., collecting location data at a city level rather than an address level), controlling the manner in which data is stored (e.g., aggregating data among users), and/or other methods, where appropriate.

Thus, while the present disclosure broadly covers the use of information that may include personal information data to implement one or more of the various disclosed embodiments, the present disclosure also contemplates that the various embodiments may be implemented without accessing personal information data. That is, various embodiments of the present technology do not fail to function properly due to the lack of all or a portion of such personal information data.

According to one embodiment, an electronic device is provided that includes a housing, a display in the housing, and a temperature sensor in the housing, the temperature sensor including an ultrasonic transmitter and an ultrasonic receiver.

According to another embodiment, the ultrasound transmitter is configured to transmit signals having different ultrasound frequencies, the electronic device further comprising a control circuit configured to determine an ambient temperature based on a phase difference between the different ultrasound frequencies received by the ultrasound receiver.

According to a further embodiment, the ultrasonic transmitter and the ultrasonic receiver are microelectromechanical system sensors.

According to another embodiment, the microelectromechanical system sensor comprises an array of piezoelectric micromechanical ultrasound transducers.

According to another embodiment, the piezoelectric micromachined ultrasonic transducer is formed on a complementary metal oxide semiconductor.

According to another embodiment, the ultrasound transmitter is one of at least three ultrasound transmitters and the ultrasound receiver is one of at least three ultrasound receivers.

According to another embodiment, each of the ultrasound transmitters is configured to transmit a signal having a different ultrasound frequency, and each of the ultrasound receivers is configured to receive the signals transmitted by all of the ultrasound transmitters.

According to another embodiment, the electronic device comprises a control circuit configured to determine an ambient temperature based on a phase difference between the different ultrasound frequencies received by the ultrasound receiver.

According to another embodiment, the housing has a cavity and the temperature sensor is mounted in the cavity.

According to another embodiment, the electronic device comprises a wire mesh covering the temperature sensor in the cavity.

According to another embodiment, the cavity is a speaker port and the wire mesh is a speaker grille.

According to a further embodiment, the ultrasound transmitter and the ultrasound receiver are separated by a gap of between 10mm and 15 mm.

According to another embodiment, the ultrasound transmitter is configured to transmit a signal having a frequency between 1MHz and 3 MHz.

According to one embodiment, an electronic device is provided that includes a housing, a temperature sensor in the housing, the temperature sensor including a plurality of piezoelectric micromachined ultrasonic transducers configured to transmit and receive ultrasonic signals, and a control circuit configured to determine an ambient temperature based on a phase difference between the received ultrasonic signals.

According to another embodiment, each of the piezoelectric micromachined ultrasonic transducers is configured to transmit and receive the ultrasonic signal.

According to another embodiment, the electronic device includes a structure within the housing, the piezoelectric micromechanical ultrasound transducer being configured to receive an ultrasound signal that has been reflected off the structure.

According to another embodiment, the piezoelectric micromechanical ultrasound transducers are formed as an array, and each of the piezoelectric micromechanical ultrasound transducers is configured to emit a different ultrasound frequency.

According to another embodiment, the housing includes a cavity, and the temperature sensor is formed in the cavity, the electronic device further including an acoustic filter covering the temperature sensor and the cavity.

According to one embodiment, an electronic device is provided that includes a housing, a display in the housing, a temperature sensor including an ultrasonic transmitter configured to transmit signals having different ultrasonic frequencies, the signals being received by the ultrasonic receiver, and a control circuit in the housing, the control circuit configured to determine an ambient temperature based on a phase difference between the received signals.

According to another embodiment, the ultrasound transmitter and the ultrasound receiver comprise an array of piezoelectric micromechanical ultrasound transducer arrays, and each of the piezoelectric micromechanical ultrasound transducer arrays comprises a piezoelectric micromechanical ultrasound transducer that detects a different ultrasound frequency.

The foregoing is illustrative and various modifications may be made to the embodiments. The foregoing embodiments may be implemented independently or may be implemented in any combination.

Claims (20)

1. An electronic device, comprising:

a housing;

a display located in the housing; and

a temperature sensor is located in the housing, wherein the temperature sensor includes an ultrasonic transmitter and an ultrasonic receiver.

2. The electronic device of claim 1, wherein the ultrasound transmitter is configured to transmit signals having different ultrasound frequencies, the electronic device further comprising:

control circuitry configured to: an ambient temperature is determined based on a phase difference between the different ultrasonic frequencies received by the ultrasonic receiver.

3. The electronic device of claim 2, wherein the ultrasonic transmitter and the ultrasonic receiver are microelectromechanical system sensors.

4. The electronic device of claim 3, wherein the microelectromechanical system sensor comprises an array of piezoelectric micromechanical ultrasonic transducers.

5. The electronic device of claim 4, wherein the piezoelectric micromachined ultrasonic transducer is formed on a complementary metal oxide semiconductor.

6. The electronic device of claim 1, wherein the ultrasound transmitter is one of at least three ultrasound transmitters, and wherein the ultrasound receiver is one of at least three ultrasound receivers.

7. The electronic device defined in claim 6 wherein each of the ultrasonic transmitters is configured to transmit a signal having a different ultrasonic frequency and wherein each of the ultrasonic receivers is configured to receive the signals transmitted by all of the ultrasonic transmitters.

8. The electronic device of claim 7, further comprising:

control circuitry configured to: an ambient temperature is determined based on a phase difference between the different ultrasonic frequencies received by the ultrasonic receiver.

9. The electronic device defined in claim 1 wherein the housing has a cavity and the temperature sensor is mounted in the cavity.

10. The electronic device of claim 9, further comprising:

a wire mesh covering the temperature sensor in the cavity.

11. The electronic device defined in claim 10 wherein the cavity is a speaker port and the wire mesh is a speaker grille.

12. The electronic device of claim 1, wherein the ultrasound transmitter and the ultrasound receiver are separated by a gap of between 10mm and 15 mm.

13. The electronic device defined in claim 12 wherein the ultrasound transmitter is configured to transmit signals having a frequency between 1MHz and 3 MHz.

14. An electronic device, comprising:

a housing;

a temperature sensor located in the housing, wherein the temperature sensor comprises a plurality of piezoelectric micromachined ultrasonic transducers configured to transmit and receive ultrasonic signals; and

control circuitry configured to: an ambient temperature is determined based on the phase difference between the received ultrasound signals.

15. The electronic device of claim 14, wherein each of the piezoelectric micromachined ultrasonic transducers is configured to transmit and receive the ultrasonic signal.

16. The electronic device of claim 14, further comprising:

a structure within the housing, wherein the piezoelectric micromachined ultrasonic transducer is configured to receive an ultrasonic signal that has reflected off of the structure.

17. The electronic device defined in claim 14 wherein the piezoelectric micromachined ultrasonic transducers are formed as an array and wherein each of the piezoelectric micromachined ultrasonic transducers is configured to emit a different ultrasonic frequency.

18. The electronic device defined in claim 14 wherein the housing comprises a cavity and wherein the temperature sensor is formed in the cavity, the electronic device further comprising:

An acoustic filter covers the temperature sensor and the cavity.

19. An electronic device, comprising:

a housing;

a display located in the housing;

a temperature sensor comprising an ultrasonic transmitter and an ultrasonic receiver, wherein the ultrasonic transmitter is configured to transmit signals having different ultrasonic frequencies, the signals being received by the ultrasonic receiver; and

a control circuit is located in the housing, the control circuit configured to determine an ambient temperature based on a phase difference between the received signals.

20. The electronic device defined in claim 19 wherein the ultrasonic transmitter and the ultrasonic receiver comprise arrays of piezoelectric micromachined ultrasonic transducer arrays and wherein each of the piezoelectric micromachined ultrasonic transducer arrays comprises a piezoelectric micromachined ultrasonic transducer that detects a different ultrasonic frequency.