electronic machinery

Abstract

To provide an electronic apparatus capable of determining whether or not an object is located in close proximity to the electronic apparatus, and provide a speaker protection module.SOLUTION: In a sound system 300, an electronic apparatus comprises a speaker protection module (SPM) 301, and sets the amplitude of the controlled sound signal such that an amplified sound signal is less than or equal to an amplitude determined to be safe for a loud speaker 310 with a consideration of one or a plurality of parameters in regard to the loudspeaker. A processing part 302 comprises a second part that analyzes at least one of the parameters, and detects a change in a response from the loudspeaker. The change in the response is caused by an object existing in an acoustic path. The second part determines whether or not the object is located in close proximity to the electronic apparatus on the basis of a result of the analysis of at least one parameter.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an electronic device and a speaker protection module. [Background technology]

[0002] Electronic devices such as mobile phones typically include proximity sensors used to detect the proximity of an object, such as a user's body part. One of the primary functions of such proximity sensors is to detect when a user holds the electronic device near their ear during a call. In this case, the touchscreen of the mobile device is disabled or switched off to prevent spurious touch events caused by the user's ear or other body part unintentionally contacting the mobile device's screen. Because the touchscreen is typically not in use while the user is holding the device near their head or ear during a call, the touchscreen controller may be configured to switch off or enter a low-power mode to conserve power. Additionally, the brightness of the device's screen is typically disabled to conserve power. Infrared (IR) proximity sensors are typically used, but ultrasonic proximity sensors are also known. Examples of solutions involving ultrasonic proximity sensors are described in European Patent No. 2271134 and US Patent Application No. 2017329431, which use a transmitter and microphone to detect the proximity of an object, and US Patent Application No. 2014126730, which aims to measure temperature and calibrate speakers to avoid overload.

[0003] Many mobile devices require a cover detection mode. Cover detection is a short-range proximity detection with the general purpose of determining whether the mobile device's screen should be enabled or should be woken from a disabled state. Therefore, one of the key objectives of a cover detection system is to prevent the screen from being unintentionally enabled. This prevents the electronic device's screen from being unintentionally enabled, resulting in unintended touch events or operations. Similarly, the cover detection mode must be reliable, allowing users to quickly access the screen whenever they want to operate the device. It is also desirable for the cover detection system to reliably distinguish between events that should enable the screen and events that should disable or keep the screen asleep. Finally, a fast cover detection response is desirable to ensure a smooth user experience.

[0004] Some users may prefer to encase their mobile devices in a cover for protection and personalization. Covers come in several varieties, including flip cases and wallets, that enclose at least a portion of the device's screen when closed. Some mobile devices adapt the device's screen to display dedicated views or menus through a translucent or transparent window when the flip cover is closed or covers the screen.

[0005] In commercially available cases, the presence of a flip cover on the screen may be detected using, for example, a touchscreen sensor on the mobile device, or a dedicated sensor, such as a near-field communication (NFC) sensor or a magnetic sensor, may be provided on the portion of the flip cover used to cover the screen. In this case, the sensor activates a detection mode of the flip case when the screen portion of the cover comes within a predetermined distance of the mobile device screen. However, covers that require a dedicated or specialized sensor for cover detection may be more expensive and less attractive to customers.

[0006] Therefore, there is a need for alternative cover detection methods and systems. Summary of the Invention [Problem to be solved by the invention]

[0007] At least some of the problems present in the prior art are solved by the features of the attached independent claims.

[0008] The present invention therefore aims to directly assess loudspeaker parameters, without relying on the use of microphones to detect return signals, as the presence of nearby objects affects the speaker's operating conditions. The proximity of an object affects the speaker's operating conditions as the object comes within a range corresponding to the wavelength of the emitted acoustic signal. For example, if a speaker moves outward toward an object, it will be sensitive to a greater-than-normal pressure between the speaker and the object, since pressure waves cannot travel freely away from the speaker. This will either restrict the movement of the membrane (speaker membrane) or increase the force required to move the membrane, representing a parameter that can be measured by a speaker control system according to the present invention.

[0009] Thus, the parameters relating to the speaker do not depend on whether the speaker can receive an acoustic signal, but only relate to the speaker under existing operating conditions: when the operating conditions change due to the presence of an object in the vicinity of the speaker, the object can be detected. [Means for solving the problem]

[0010] According to the first aspect, a first portion configured to generate an audio signal; a loudspeaker for generating an acoustic signal; In some embodiments, the loudspeaker may include a moving membrane, or alternatively, a glass screen with a piezo actuator or microphone configured to transmit sound, whereby the membrane described below can be understood to be the active part of the glass screen or microphone.

[0011] The device also includes a speaker protection module including a processing unit configured to receive the audio signal at the processing unit and configured to generate a controlled audio signal using one or more parameters related to the loudspeaker via the processing unit.

[0012] The device also includes an amplifier configured to amplify at least the controlled audio signal to generate an amplified audio signal that is sent to a loudspeaker to generate an acoustic signal.

[0013] Here, the amplitude of the controlled audio signal is set so that the amplified audio signal is at or below an amplitude determined to be safe for the loudspeaker taking into account one or more parameters.

[0014] The electronic device also includes a second portion configured to analyze at least one of the one or more parameters related to the loudspeaker to detect a change in the response of the movable membrane, the change in the response being caused by an object present in the acoustic path of the membrane, and to determine whether the object is located in the vicinity of the electronic device based on the analysis of the at least one parameter.

[0015] It should be noted that, in this specification, the term "audio signal" refers to an electrical signal representing an acoustic signal transmitted or received within or outside the audible range appropriate for the available transducers. Proximity broadly means less than 5 cm from the loudspeaker.

[0016] It should also be noted that the amplified audio signal is dependent on the controlled audio signal, in other words, the amplified audio signal comprises at least partly the controlled audio signal multiplied by the gain of the amplifier, or the amplified audio signal comprises at least partly both the amplified and controlled audio signals.

[0017] In doing so, one or more parameters related to the loudspeaker can be used to perform cover detection or near-field proximity detection, as well as to adapt and modify the controlled audio signal so that the amplified audio signal fed to the loudspeaker is within the loudspeaker's excursion and / or temperature limits. This provides significant advantages in terms of cost, design, and even performance. By using existing hardware used for speaker protection, the proposed electronics and SPM can also be used for near-field proximity measurements, thus eliminating the need to provide a separate proximity detection system.

[0018] It should also be noted that detecting or measuring changes in the response of the movable membrane can be done at least in part using the same loudspeaker parameters that are measured to monitor and / or modify the amplitude of the controlled audio signal so that it is within an amplitude determined to be safe. Measuring changes in response can also be done at approximately the same time as monitoring the amplitude using the loudspeaker parameters.

[0019] It should be noted that the change in response can be primarily caused by the reflection of the acoustic signal and its interaction with a loudspeaker, including a membrane or glass screen with a piezoelectric actuator, or a microphone configured to transmit sound. The membrane's response differs when there is no object in the acoustic path of the acoustic signal generated by the membrane compared to when an object is present in the acoustic path such that at least a portion of the acoustic signal is reflected by the membrane. When the reflected signal reaches the membrane, at least some of the acoustic energy is transferred to the membrane, resulting in a change in the membrane's response. The applicant has realized that this change in response can be measured by monitoring at least some of the loudspeaker parameters used for speaker protection. Compared to conventional acoustic detection systems, there is no need to transmit and then listen with a transducer. Detection can be performed while verifying the loudspeaker's safety limits. This, combined with the advantage that the SPM can perform both functions simultaneously, can be a significant commercial and technical advantage.

[0020] An additional benefit is that when audio is being played by an electronic device, any separate cover detection system present on the device can be disabled and SPM can be used for cover detection or close-range proximity detection, thereby saving power and improving available battery life.

[0021] According to one embodiment, at least a portion of the one or more parameters are used to define a loudspeaker model. The loudspeaker model may be stored in memory in either the SPM and / or another accessible portion of the electronics. The loudspeaker model may be representative of a transfer function of the loudspeaker. Thus, the electronics, via the speaker protection module, or more specifically, via the processing unit, can determine an expected response of the loudspeaker at a given audio input signal value. The audio input signal value may be provided at an audio input portion of the speaker protection module. The loudspeaker model may be dynamically updated by the SPM using calibration or in real time. The SPM may use one or more calibration signals, such as pilot tones, to calibrate the loudspeaker model.

[0022] According to another aspect, the electronic device is configured to transmit ultrasonic signals either through the same loudspeaker or through a separate transducer. Those skilled in the art will appreciate that ultrasonic transducers are a type of acoustic transducer based on transmitting and / or receiving acoustic signals in the ultrasonic range. Because ultrasonic signals are outside the range of typical human hearing, they may be transmitted from the electronic device alone or simultaneously with audio signals, such as a speaker output during music playback or a phone call. Thus, the electronic device may use ultrasonic proximity detection simultaneously with or instead of audible acoustic signals via a loudspeaker. The electronic device may also include one or more ultrasonic receivers for receiving the ultrasonic signals or their reflected signals.

[0023] According to one aspect, at least one of the one or more parameters for the loudspeaker is derived from the amplified audio signal. For example, the at least one parameter is an I / V signal derived from the amplified audio signal. Thus, at least one of the one or more parameters is an electrical signal for the loudspeaker. Also, at least one of the parameters may be a reference value of the I / V signal. Also, some of the parameters may be model parameters or thresholds that are compared or correlated with the respective electrical signals for the loudspeaker derived via the amplified audio signal.

[0024] According to one embodiment, the second part is at least partially part of the processing unit, which can provide further advantages in terms of cost and also performance by at least partially reusing the processing already performed by the processing unit to generate the controlled audio signal, so that the second part can be the same processor as the processing unit in terms of hardware.

[0025] Therefore, the present invention can provide a speaker protection module, which includes: a controlled output configured to generate a controlled audio signal via a processing unit; and an amplifier output configured to send an amplified audio signal to a loudspeaker; an amplifier configured to amplify at least the controlled audio signal to generate an amplified audio signal; wherein the amplitude of the controlled audio signal is set such that the amplified audio signal is equal to or less than an amplitude determined to be safe for the loudspeaker taking into account one or more parameters extracted from the amplified audio signal. Further, the processing unit is configured to analyze at least one of the one or more parameters extracted from the amplified audio signal to detect changes in the response of the loudspeaker to determine if an object is present in the vicinity of the loudspeaker. Also, instead of the processing unit configured to receive the audio signal, the device may include an audio input configured to receive the audio signal.

[0026] According to yet another aspect, a method for detecting an object in the vicinity of an electronic device may be provided, the method comprising: receiving an audio signal at an audio input; processing the audio signal using a processing unit; generating, via a processing unit, a controlled audio signal using one or more parameters related to the loudspeaker; amplifying at least the controlled audio signal using an amplifier to produce an amplified audio signal at the amplifier output, wherein the amplitude of the controlled audio signal is set such that the amplified audio signal is at or below an amplitude determined to be safe for the loudspeaker taking into account one or more parameters; sending the amplified output signal to a loudspeaker operatively connected to the amplifier output; determining at least one parameter related to the loudspeaker using the amplified audio signal; generating an acoustic signal dependent on the amplified output signal via a moving membrane of the loudspeaker; analyzing at least one of one or more parameters related to the loudspeaker to detect a change in the response of the movable membrane, wherein the change in response is caused by an object present in the acoustic path of the membrane; determining whether an object is located in the vicinity of the electronic device based on results of the analysis; Includes:

[0027] According to yet another aspect, the present invention may provide a computer software product for implementing any of the method steps described herein using a suitable processor. Accordingly, the present invention also relates to a computer-readable program code having specific capabilities for performing any of the method steps described herein. In other words, the present invention also relates to a non-transitory computer-readable storage medium storing a program for causing an electronic device to perform any of the method steps described herein.

[0028] More specifically, a computer software product may also be provided, wherein the computer software product, when executed by a processor of an electronic device, causes the electronic device to: receiving an audio signal at the audio input; Use a processor to process the audio signal; via a processor, generating a controlled audio signal using one or more parameters related to the loudspeaker; amplifying at least the controlled audio signal using an amplifier to produce an amplified audio signal at the amplifier output, wherein the amplitude of the controlled audio signal is set such that the amplified audio signal is at or below an amplitude determined to be safe for the loudspeaker taking into account one or more parameters; sending the amplified output signal to a loudspeaker operatively connected to the amplifier output; Using the amplified audio signal, determining at least one parameter related to the loudspeaker; generating an acoustic signal dependent on the amplified output signal via a moving membrane of the loudspeaker; analyzing at least one of one or more parameters related to the loudspeaker to detect a change in the response of the movable membrane, wherein the change in response is caused by an object present in an acoustic path of the membrane; Based on the results of the analysis, determine whether an object is located in the vicinity of the electronic device.

[0029] Those skilled in the art will appreciate that the invention described herein is not limited to loudspeakers with windings or coils. For ease of explanation, such loudspeakers are described in the examples herein. Thus, any type of acoustic transducer that may require protection from overdrive and therefore uses an SPM can benefit from the present invention for proximity detection, so long as it is capable of detecting changes in the transducer's response due to an object introduced into the acoustic path. For example, certain types of piezoelectric transducers may be used for transmitting sound. Thus, the present invention may be suitable for providing proximity detection capabilities while mitigating similar overdrive problems in such piezoelectric transducers or other types of acoustic transducers.

[0030] It should also be noted that the processing unit may be any type of computer or data processor, such as a microprocessor or microcontroller. Furthermore, the processing unit or processor may be a DSP, FPGA, or ASIC. The processing unit may be a combination of different hardware elements or modules. In some cases, the processing unit may essentially be a virtual machine running on a processor. In some cases, the processing unit may include a machine learning module to improve the accuracy of measurements depending on the use case of the electronic device. Furthermore, the processing unit may include a machine learning (ML) module and / or an artificial intelligence (AI) module.

[0031] The electronic device may be any device, such as a mobile or stationary device. Thus, devices including mobile phones, tablets, voice assistants, smart speakers, laptop computers, desktop computers, and similar devices are included within the scope of the term electronic device in this specification. Devices including internet routers, vending machines, video games, automobiles, gates, doors, home appliances, and other types of electronic devices are also included within the scope of the term electronic device.

[0032] The processing of the ultrasonic signal may be based on a measurement of the time of flight (TOF) between the transmitted ultrasonic signal and the corresponding reflected signal or echo signal received by the ultrasonic receiver. The receiver converts the echo signal into a measured signal. The processing of the echo signal may also be based on the amplitude of the measured signal, the phase difference between the transmitted signal and the measured signal, the frequency difference between the transmitted signal and the measured signal, or a combination thereof. The transmitted ultrasonic signal may include a single frequency or multiple frequencies. In some cases, the transmitted ultrasonic signal may include a chirp. [Brief explanation of the drawings]

[0033] Exemplary embodiments will now be described with reference to the accompanying drawings, which may not necessarily be drawn to scale, without affecting the scope of generality of the invention. [Figure 1] FIG. 1 is a front perspective view of an electronic device having a proximity detection system. [Figure 2] 1 is a side perspective view of an electronic device having a proximity detection system. [Figure 3] FIG. 1 is a block diagram of an audio system with a speaker protection module (SPM). [Figure 4] FIG. 1 illustrates a short-range proximity measurement using an SPM. [Figure 5] FIG. 1 is a flow diagram of a short-distance proximity measurement method using an SPM. DETAILED DESCRIPTION OF THE INVENTION

[0034] Electroacoustic transducers, such as loudspeakers (speakers), are used to convert electrical energy into acoustic energy. When a typical speaker is activated, a current flows through the speaker's windings, generating a magnetic field. Within this field, the windings (voice coils) are moved by magnetic forces. Attached to the windings is a movable membrane, which contains all of the moving parts of the speaker, such as the diaphragm, frame, and damper (suspension). This causes the membrane to move in concert with the windings, generating an acoustic signal that corresponds to the current flowing through the windings.

[0035] Speakers can be damaged by being overdriven, i.e. by driving them with a signal of too large amplitude or power. Speakers are damaged primarily by mechanical causes, for example by excessive stretching of the moving membrane, or by thermal causes, usually by excessive temperatures occurring in the windings. When a speaker is driven, the current flowing in the windings generates a voltage I 2 R losses occur, causing the winding to heat up. Excessive heat can damage the winding, or it can melt the epoxy around the winding, preventing further movement of the membrane. It can also be a combination of these. Therefore, some electronic devices employ "Speaker Protection Modules (SPMs)" to protect the loudspeaker from being overdriven, in order to maximize the sound output from the loudspeaker while avoiding damage to the loudspeaker.

[0036] Modern electronic devices, such as mobile phones and tablets, typically include hardware that generates audible sound, e.g., for playing multimedia content such as music and video, and for telecommunications such as phone calls. This hardware typically includes an amplifier, such as a power amplifier (PA), that is arranged to receive an input signal (e.g., from a microprocessor, memory, storage medium, etc.) and amplify it to a state suitable for driving a loudspeaker. Maximizing audio performance is particularly important in portable devices, where size and weight are critical.

[0037] An SPM typically includes a power amplifier and a speaker protection algorithm, which protects the speaker from damage caused by excursions and heat. The SPM typically monitors the loudspeaker's output power (e.g., by monitoring a signal indicative of the drive power supplied to the loudspeaker) and other local environmental factors such as temperature, and feeds these into the speaker protection algorithm, which dynamically adjusts the electrical signal supplied to the speaker in order to optimize speaker protection. This prevents the loudspeaker from being overdriven without imposing unnecessary limitations on output (e.g., by limiting the amplitude of the audio output signal more than is actually required), allowing the loudspeaker to always be driven to its full potential, as long as conditions permit.

[0038] Typically, an audio signal output by an electronic device through a loudspeaker passes through an SPM from a source such as a microprocessor or system-on-chip (SoC) before being amplified by an amplifier. The SPM typically receives the input audio signal and generates a controlled audio signal at the same level that the speaker can currently safely receive after amplification. The amplified and controlled audio signal is then typically used to directly drive the loudspeaker. If the speaker protection module is properly calibrated, it can prevent the loudspeaker from overdriving. Thus, as described above, a movable membrane is used to generate an acoustic signal that depends on the amplified audio signal.

[0039] One or more parameters related to the loudspeaker may be used to derive a temperature of the loudspeaker and / or a model of the loudspeaker, for example, the loudspeaker model may be used to estimate the excursion of the membrane.

[0040] The signal indicative of the drive power supplied to the loudspeaker is typically an I / V signal. This may be generated by an I / V sense resistor or other electrical element capable of directly or indirectly providing a signal indicative of the drive power. The electrical element may also be multiple components. The electrical element may be any suitable current-sensing element. According to one embodiment, the I / V sense signal may be a differential signal measured across the electrical element. For example, the differential signal may be a voltage drop across an electrical element such as a resistor, a passive or active semiconductor element, or a current mirror. The I / V signal may undergo signal processing such as amplification, filtering, and averaging. The signal processing may also include analog-to-digital conversion using, for example, an analog-to-digital converter (ADC). The I / V signal may then be converted to a digital I / V signal for further analysis using a digital processor, for example, a microprocessor, FPGA, or digital signal processor (DSP). Those skilled in the art of amplifiers will understand how the I / V sensing and signal processing functions. Therefore, further details regarding the same will not affect the scope or generality of the present invention and will not be described herein.

[0041] The speaker temperature and speaker model are derived from the I / V sense and are used to modify the input signal in the power / excursion protection block accordingly so that the output provided to the speaker is within the excursion and temperature limits of the speaker.

[0042] Ultrasonic sensors are a type of acoustic sensor that utilizes the transmission and reception of acoustic signals in the ultrasonic range. Because ultrasonic signals are outside the range of typical human hearing, they may be transmitted by electronic devices either alone or in conjunction with audio signals, such as music playback or speaker output during a phone call.

[0043] FIG. 1 is an exemplary front perspective view of an electronic device 100, shown here as a mobile phone or smartphone. The mobile phone 100 has a screen 101 for displaying content and for interacting with the device 100. Located above the top edge 110 of the screen 101 are earphones 102 and a proximity sensor 106. Note that the terms top, bottom, left, and right are used relative to one another herein to facilitate understanding of the invention. Furthermore, the location of each component, such as the proximity sensor 106, is shown by way of example only. Those skilled in the art will appreciate that such sensors or earphones 102 can be located in different locations than in this example without affecting the scope or generality of the present invention.

[0044] As described below, the earphones 102 include speakers used to output acoustic signals, such as audio for phone calls. In certain phones, the same speakers in the earphones 102 may also be used to output ultrasonic signals, for example, for ultrasound-based user interaction. The screen 101 may include not only a display for displaying content, such as photos and videos, but also a touchscreen sensor for touch-based user interaction. The proximity sensor 106 is sometimes based on infrared (IR) detection, but may also be a sensor based on acoustic detection or another type of sensor suitable for proximity detection. The proximity sensor 106 has a field of view (FoV), which is a three-dimensional envelope or space around the sensor 106 within which the sensor 106 can reliably detect proximity events, such as nearby events. Detection of nearby events may be used, for example, to turn off the touchscreen and display (or screen 101) of the device 100 so that undesired touchscreen activity can be prevented. Such undesired touchscreen activity may occur when the user places the earphones 120 in contact with or close to their ears and when the touchscreen is not disabled. Detection of a proximity event using the proximity sensor 105 is used to disable the touchscreen to prevent unwanted touchscreen activity.

[0045] Also shown in Figure 1 are a pair of loudspeakers 105 and a microphone 103. Some telephones may include one or more other speakers, such as speaker 105, used for hands-free operation and / or audio playback. Such other speakers 105 may be different from the earphones 102. Such speakers 105 may also be larger than the earphone speakers. In the illustrated embodiment, left speaker 105a and right speaker 105b may be used to play stereo audio. Typically, microphone 103 on the bottom of telephone 100 is used specifically for calls when the user holds earphones 102 close to the ear. Microphone 103 may also be used for hands-free operation or other audio capture or recording purposes.

[0046] Some telephones may also include one or more additional microphones, such as microphone 104 located on the top of the telephone. The additional microphones may be used, for example, for stereo sound capture or other purposes. Multiple microphones may be provided on either the top and / or bottom or sides of device 100. In some devices, multiple microphones and / or multiple speakers may be used for ultrasonic interaction with device 100. In some cases, such ultrasonic sensing device placement, achieved by speakers and microphones, may obviate the requirement for a dedicated proximity sensor 106. Thus, in such cases, device 100 may not have a separate proximity sensor 106.

[0047] 1, proximity sensor 106 requires significant space on the screen side of the device. Therefore, in most cases, a bezel 120 may be required to accommodate components such as a dedicated proximity sensor 160. In the absence of such components, screen 101 can extend toward the edge of the device. This allows all or most of the screen side of device 100 to be used as display area, rather than wasting space in the dead area of ​​bezel 120.

[0048] One of the functions performed by the proximity sensor 106 is cover detection. Cover detection is proximity detection for objects in the vicinity of the device 100, or more precisely, the proximity sensor 106. Thus, cover detection is triggered when one or more objects, such as a user's head, a user's palm, the side of a pocket or bag, or a closed or nearly closed flip cover, are present within, for example, 5 cm of the FoV of the proximity sensor 106. Alternatively, more generally, a near state of the cover detection function can be triggered by bringing an object at least the size of an adult finger within 5 cm of the FoV of the proximity sensor 106. Similarly, a far state of the cover detection function can be triggered when an object is more than 5 cm away from the FoV and / or the sensor 106. Note that the near and far states are mutually exclusive; i.e., the far state occurs when the near state is not detected.

[0049] Cover detection needs to be reliable and factual to ensure a smooth user experience and prevent false near and / or far detections, which also has the benefit of saving battery power.

[0050] FIG. 2 is a side perspective view of the phone 100. The FoV 205 of the proximity detection system extends from the proximity sensor 106 along an axis 206, and the cross-sectional area of ​​the FoV 205 in a plane perpendicular to the axis 206 increases with distance from the proximity sensor 106 along the axis 206. Typically, the FoV 205 extends to a certain distance 250 from the sensor 106. Thus, the FoV 205 is the region or 3D space within which the proximity detection system can reliably detect the presence of an object. In this example, the FoV 205 is shown as a cone with its apex at the proximity sensor 106, and the base 207 of the cone represents the limit of the region where reliable detection is possible. Alternatively, the base 207 of the cone could represent the limit where proximity detection is desired. The cone shape of the FoV 205 is shown merely as an example. In some cases, the FoV 205 may be asymmetric in any or all directions or may have another shape depending on the sensor used. For example, an ultrasound-based proximity sensor typically has a wider FoV 205 than an IR-based proximity sensor 106. Furthermore, the FoV 205 may extend in a plane that is not perpendicular to the axis 206, i.e., at another angle. Those skilled in the art will recognize that the particular shape of the FoV 205 does not limit the scope or generality of the present invention.

[0051] 3, there is shown an audio system 300 comprising a speaker protection module (SPM) 301. The SPM 301 comprises at least one input and at least one output. The SPM 301 comprises at least an audio input 304. The SPM 301 also comprises an amplifier audio output 306a operatively connected to a loudspeaker 310.

[0052] The audio input 304 is configured to receive an audio signal. The audio signal may be received at the audio input 304 via any suitable module or device, such as, for example, an audio DSP of an electronic device. The audio input 304 is operatively connected to the processing unit 302. Thus, the audio signal received at the audio input 304 is sent to the processing unit 302, either directly or via another module. The processing unit 302 may comprise a hardware signal processing module and / or be configured to execute a speaker protection algorithm to protect the loudspeaker 310.

[0053] Thus, the processing unit 302 generates a controlled audio signal at a controlled output 305 operatively connected to the amplifier 303 .

[0054] The amplifier 303, either directly or via another module, is configured to amplify the controlled audio signal to produce an amplified audio signal at the amplifier output 306a.

[0055] The amplifier output 306a is configured to send an amplified audio signal to the loudspeaker 310, either directly or via other suitable equipment, such as a buffer, another amplifier, an attenuator, a filter, or other signal processing equipment, or any combination of such signal processing equipment. The loudspeaker 310 is thus configured to generate an acoustic signal that depends on the amplified output signal. As described above, the acoustic signal is generated via the movable membrane of the loudspeaker 310.

[0056] To protect the loudspeaker 310, the processing unit 302 is configured to monitor the amplified output signal. Thus, the processing unit 302 uses one or more parameters related to the loudspeaker 310 for overdrive protection. At least one of the parameters is derived from the amplified output signal or from sensing performed at the amplifier output 306 a. In some cases, some parameters may be specifications and / or mathematical models of the loudspeaker 310. In some cases, the model of the loudspeaker 310 is derived at least in part from measurements made at the amplifier output 306 a.

[0057] Measurement or sensing at the amplifier output 306a can be performed, for example, by I / V sensing at the amplifier audio output 306a. Thus, by placing a current sensing element, such as a resistor, in series with one terminal connected toward the amplifier 303 and the other terminal connected toward the speaker 310, the current sent to the speaker 310 can flow through the current sensing element. Those skilled in the art will appreciate that this current will result in a voltage drop across the component, which depends on the current or power sent to the speaker 310. Any suitable sensing element 320, connected in series as described above and / or in a different arrangement relative to the amplifier output 306a, can be used, so long as the sensing element 320 or its arrangement can provide a signal indicative of at least one parameter related to the speaker 310. Here, the signal can be used to protect the speaker 310 from mechanical and / or thermal overdrive. Other examples of such components include current mirrors, shunt resistors, voltage dividers, current sensing amplifiers, differential amplifiers, and transformers. The particular type of detection does not limit the scope or generality of the invention.

[0058] Here, the amplitude of the controlled audio signal is set such that the amplified audio signal is equal to or less than the amplitude determined to be safe for the loudspeaker. Thus, the processing unit 302 is configured to generate, at the controlled output 305, the controlled audio signal such that the amplified audio signal has an amplitude such that the amplified audio signal is equal to or less than the amplitude determined to be safe for the loudspeaker taking into account one or more parameters. In other words, the processing unit 302, via a hardware module and / or a speaker protection algorithm, adapts the controlled audio signal such that the amplified audio signal is equal to or less than the amplitude determined to be safe for the loudspeaker.

[0059] 3, the sensing element 320 is shown in series between the amplifier output 306a and the measured amplifier output 306b, but as noted above, it could be any type of component. In some cases, the sensing element 320 may be contained at least partially within the processing unit 302, or may be contained entirely within the processing unit 302. Note that if the sensing element 320 is contained within the processing unit 302, the measured amplifier output 306b will also be contained within the processing unit 302. In such cases, the amplifier output 306a may also be directly connected to the processing unit 302.

[0060] Although amplifier 303 is shown as part of SPM 301, it may also be at least partially external to SPM 301. In some cases, amplifier 303 may be at least partially part of the processing section.

[0061] Referring now to FIG. 4, a near-field proximity measurement using SPM 301 is shown. For simplicity, not all parts of SPM 301 are explicitly shown in FIG. 4. Furthermore, sensing element 320 is not shown. As noted above, component 320 may be considered present in FIG. 4 or may be considered part of processing unit 302. In FIG. 4, controlled output 305 provides a controlled audio signal to amplifier 303. Amplifier 303 generates an amplified audio signal at amplifier output 306a that is dependent on the controlled audio signal. The amplified audio signal is provided to loudspeaker 310, which generates acoustic signal 401 that is dependent on the amplified audio signal.

[0062] More specifically, referring to Figure 4A, a condition is shown in which no object is present in the vicinity of the speaker 310. In this case, in Figure 4A, the signal at the amplifier output 306a, or a measured copy of the signal, is provided to the processing unit 302. In this manner, the processing unit 302 adapts the controlled audio signal so that the amplified audio signal is at or below an amplitude determined to be safe for the loudspeaker 310.

[0063] 4B shows a user's hand 410 in proximity to a speaker 310. More specifically, the hand 410 is within the acoustic path of the speaker 310. The acoustic path can be thought of as the field of view (FoV) of the speaker 310. This allows reflections 402 of an acoustic signal 401 to reach the speaker 310 and cause a measurable signal change 405 at the amplifier output 306a or at the input of the speaker.

[0064] Via the sensing element 320, a signal change 405 in the amplified audio signal, more specifically the signal supplied to the speaker 310, can be measured. This change can then be used by the processing unit 302 to determine the presence of an object (here a hand 410) in the vicinity of the speaker 310 or the electronic device of which the speaker 310 is a part.

[0065] The signal change 405 results in a change in the response or dynamics of the speaker 310, which can be measured via the sensing element 320. Note that both the distance of the object from the speaker and the size of the object are important to cause a measurable change 405. More specifically, to be reliably detected, the object must be larger than a certain size, and the object's distance from the speaker 310 must be less than a certain value. Furthermore, each specific object may have a specific maximum distance at which it can be detected. Since the scope of the present invention is cover detection, i.e., detecting the state when an electronic device is "covered," it will be clear to one skilled in the art what types of objects can and should be detected using the present invention. It is not necessary to describe what the object looks like or what size it is. As non-limiting examples, the object may be one or more, or a combination, of a user's finger, hand, cover, the surface of a piece of paper or book, and the surface of a pocket or bag.

[0066] The signal variation 405 may be caused, for example, by standing waves resulting from the acoustic signal 401 interacting with its reflection 402. Additionally, other phenomena such as resonance may also contribute to the signal variation 405.

[0067] In some cases, the input of the speaker 310 is the same as the input connected to the amplifier output 306a. Alternatively or additionally, the input can be a different interface of the speaker dedicated to measuring at least some of the parameters of the speaker 310. As will be understood herein, the different interface can be one or more terminals coupled to the membrane of the speaker 310 for measuring at least some of the parameters of the speaker.

[0068] FIG. 5 is a flow diagram 500 of a method for near-field proximity detection using SPM. At start 501, an audio signal is received. The audio signal may be received at audio input 304. Then, in another step 502, the audio signal, or a copy thereof, is processed. The audio signal may be processed using processing unit 302. In yet another step 503, a controlled audio signal is generated. The controlled audio signal may be generated by processing unit 302, for example, at controlled output 305. The controlled audio signal is further processed using one or more parameters related to loudspeaker 310. In another step 504, an amplified audio signal is generated. The amplified audio signal may be generated by amplifying the controlled audio signal using amplifier 303. Preferably, the amplitude of the controlled audio signal is set so that the amplified audio signal is equal to or less than an amplitude determined to be safe for loudspeaker 310 taking into account one or more parameters. In another step 505, the amplified audio signal is sent to loudspeaker 310. The loudspeaker 310 is operatively connected to the amplifier output 306a. In another step 506, the signal at the amplifier output 306a, i.e., the amplified audio signal, is used to determine at least one parameter related to the loudspeaker 310. The sensing element 320 may be used to provide a measurement of the amplified audio signal to the processing unit 302. This allows, for example, in step 503, the processing unit 302 to adapt the amplitude of the controlled audio signal so that the amplified audio signal is equal to or less than an amplitude determined to be safe for the loudspeaker 310. In yet another step 507, an acoustic signal is generated. The acoustic signal is generated by the loudspeaker 310 and depends on the amplified audio signal. It should be noted that the acoustic signal is generated via a movable membrane of the loudspeaker 310. In another step 508, a change in the response of the movable membrane caused by an object is detected. The change in the membrane response can be detected by analyzing at least one of one or more parameters related to the loudspeaker 310.More specifically, as shown diagrammatically in step 506, the change in response can be detected by analyzing the amplified audio signal or a derivative thereof. Thus, the signal change 405 can be measured by the processing unit. In the following step 509, based on the results of the analysis, it is determined whether an object is in the vicinity of the loudspeaker 310. The determination can be made by the processing unit 302.

[0069] In the final step 510, the method may end, or may be repeated from the first step, or from any of the intermediate steps.

[0070] Various embodiments have been described above for electronic devices including SPMs for proximity detection, SPMs capable of proximity detection, methods for proximity detection using SPMs, and computer software products that at least partially implement the methods. However, those skilled in the art will appreciate that changes and modifications can be made to the above examples without departing from the spirit and scope of the appended claims and their equivalents. It will also be understood that aspects and / or features from the method and product embodiments described herein can be freely combined.

Claims

1. An electronic device, a controlled output configured to generate an audio signal including frequencies outside the audible range; a loudspeaker for generating an acoustic signal; a speaker protection module including a processing unit, the speaker protection module being configured to generate a controlled audio signal using one or more parameters related to the loudspeaker via said processing unit; an amplifier configured to amplify at least the controlled audio signal to produce an amplified audio signal, the amplified audio signal being sent to the loudspeaker to produce the acoustic signal; and Equipped with setting the amplitude of the controlled audio signal so that the amplified audio signal is at or below an amplitude determined to be safe for the loudspeaker taking into account the one or more parameters; The electronic device includes: a processor configured to analyze at least one of the one or more parameters related to the loudspeaker to detect a change in a response of the loudspeaker, wherein the change in response is caused by an object present in an acoustic path, the processor configured to determine whether the object is located in the vicinity of the electronic device based on a result of analyzing the at least one parameter; a movable membrane included in the loudspeaker, wherein a change in the response of the movable membrane is caused by the object being present in an acoustic path of the movable membrane, and the processor is configured to determine whether the object is located in the vicinity of the electronic device based on a result of the analysis of the at least one parameter; Further provided with electronic equipment.

2. the controlled audio signal is in the near ultrasonic range; The electronic device according to claim 1 .

3. a memory storing said at least one parameter, said at least one parameter being defined by a predetermined loudspeaker model representing said loudspeaker; The electronic device according to claim 1 .

4. the stored parameters are calculated from measured performance without the object in the acoustic path; The electronic device according to claim 3 .

5. one of the at least one parameter is an I / V signal measured from the amplified audio signal; The electronic device according to claim 1 .

6. one of the parameters is a reference value of the I / V signal; The electronic device according to claim 5 .

7. the processing unit is configured to receive the acoustic signal at an audio input; The electronic device according to claim 1 .

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