Ultrasonic fingerprint detection method and apparatus, and electronic device and storage medium

Abstract

Provided in the embodiments of the present application are an ultrasonic fingerprint detection method and apparatus, and an electronic device and a storage medium. The ultrasonic fingerprint detection method comprises: acquiring the current temperature and / or the current film status of a conductive medium, wherein a first side surface of the conductive medium is attached to an ultrasonic sensor, and a second side surface of the conductive medium provides a pressing surface; on the basis of the current temperature and / or the current film status, determining the number n of transmissions of ultrasonic waves, wherein n is a positive integer; controlling the ultrasonic sensor to transmit ultrasonic signals to the conductive medium n times, and receiving an echo signal formed after each transmitted ultrasonic signal is reflected; and performing fingerprint detection on the basis of the echo signal. The embodiments of the present application can significantly reduce the impact of noise on fingerprint detection, and can ensure the stability of the accuracy of fingerprint detection, thereby improving the performance of fingerprint detection.

Description

Ultrasonic fingerprint detection methods, devices, electronic equipment and storage media

[0001] This application claims priority to the invention application filed on June 17, 2024, with application number "202410777108.5" and patent title "Ultrasonic fingerprint detection method, device, electronic device and storage medium", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of electronic technology, and in particular to an ultrasonic fingerprint detection method, apparatus, electronic device, and storage medium. Background Technology

[0003] Ultrasonic testing is a non-destructive testing technique that utilizes the interaction between ultrasonic waves and matter. It has wide applications in fingerprint detection, flaw detection, and many other fields. Currently, fingerprint detection technologies using ultrasonic sensors typically utilize a conductive medium, such as a screen or cover plate, that is attached to the ultrasonic sensor to provide the surface for finger pressure. During fingerprint detection, the ultrasonic sensor emits ultrasonic signals into the conductive medium and receives the echo signals, which are then used for fingerprint detection.

[0004] However, some shortcomings still exist in the related technologies. For example, the ultrasonic signals emitted by ultrasonic sensors experience some loss when propagating in the transmission medium. The intensity of the received echo signal is significantly reduced compared to the emitted ultrasonic signal, resulting in a significant increase in noise in the echo signal. Furthermore, the loss of ultrasonic signals in the transmission medium usually varies depending on the usage scenario (such as different temperatures). When facing different usage scenarios, the received echo signals are prone to large fluctuations, making it difficult to guarantee the stability of fingerprint detection accuracy. Summary of the Invention

[0005] In view of this, embodiments of this application provide an ultrasonic fingerprint detection method, apparatus, electronic device, and storage medium, which at least partially solve the above-mentioned problems.

[0006] According to a first aspect of the embodiments of this application, an ultrasonic fingerprint detection method is provided, comprising: acquiring the current temperature and / or current film application state of a conductive medium, wherein a first side of the conductive medium is attached to an ultrasonic sensor, and a second side of the conductive medium provides a pressing surface; determining the number of ultrasonic transmissions n based on the current temperature and / or the current film application state, wherein n is a positive integer; controlling the ultrasonic sensor to transmit n ultrasonic signals to the conductive medium, and receiving the echo signal formed after each transmitted ultrasonic signal is reflected; and performing fingerprint detection based on the echo signal.

[0007] In one possible implementation, determining the number of ultrasonic emissions n based on the current temperature includes: determining the number of ultrasonic emissions n based on the current temperature and first mapping information, wherein the first mapping information is used to indicate the mapping relationship between the temperature of the conductive medium and the number of ultrasonic emissions; determining the number of ultrasonic emissions n based on the current film application state includes: determining the number of ultrasonic emissions n based on the current film application state and second mapping information, wherein the second mapping information is used to indicate the mapping relationship between the film application state of the conductive medium and the number of ultrasonic emissions; determining the number of ultrasonic emissions n based on the current temperature and the current film application state includes: determining the number of ultrasonic emissions n based on a current parameter combination and third mapping information, wherein the current parameter combination includes the current temperature and the current film application state, and the third mapping information is used to indicate the mapping relationship between the temperature of the conductive medium, the film application state, and the number of ultrasonic emissions.

[0008] In one possible implementation, the method further includes updating the first mapping information; the updating of the first mapping information includes:

[0009] The updated temperature of the conductive medium is obtained; based on the updated temperature and the first mapping information, the number of ultrasonic transmissions m corresponding to the updated temperature is determined; where m is a positive integer; the ultrasonic sensor is controlled to transmit m ultrasonic signals to the conductive medium, and the updated echo signal formed after each transmitted ultrasonic signal is reflected is received, wherein the temperature of the conductive medium when the ultrasonic sensor transmits the m ultrasonic signals is the updated temperature; the m updated echo signals are superimposed to obtain an updated cumulative sum signal; the number of ultrasonic transmissions m is updated based on the intensity of the updated cumulative sum signal and a preset signal intensity range.

[0010] In one possible implementation, updating the number of ultrasonic transmissions m based on the strength of the updated accumulated signal and a preset signal strength range includes:

[0011] If the intensity of the updated cumulative signal is within the signal intensity range, then the number of ultrasonic wave transmissions m is updated to remain at m.

[0012] If the intensity of the updated accumulated signal is outside the signal intensity range, the number of updated ultrasonic wave emissions corresponding to the updated temperature is determined according to the following formula: N 更新 =m*P 目标 / P 样本

[0013] N 更新 P is used to indicate the number of times the updated ultrasonic wave is emitted. 目标P is used to indicate the median value of the signal strength range. 样本 Used to indicate the strength value of the updated accumulated signal;

[0014] Update the number of ultrasonic wave emissions m to the updated number of ultrasonic wave emissions.

[0015] In one possible implementation, when the ultrasonic sensor emits the m ultrasonic signals, there is no finger pressing on the pressing surface; when the updated temperature of the conductive medium is obtained, there is no finger pressing on the pressing surface; when the ultrasonic sensor emits the n ultrasonic signals to the conductive medium, there is finger pressing on the pressing surface; when the current temperature of the conductive medium is obtained, there is finger pressing on the pressing surface.

[0016] In one possible implementation, the first mapping information includes the temperature of the conductive medium, the number of ultrasonic emissions mapped to the temperature of the conductive medium, and the update status of the number of ultrasonic emissions; determining the number of ultrasonic emissions n based on the current temperature and the first mapping information includes: determining the number of ultrasonic emissions mapped to the current temperature based on the current temperature and the first mapping information; if the update status of the number of ultrasonic emissions mapped to the current temperature is marked as updated, then the number of ultrasonic emissions mapped to the current temperature is determined as the number of ultrasonic emissions n; if the update status of the number of ultrasonic emissions mapped to the current temperature is not marked as updated, then the number of ultrasonic emissions n is determined based on the update status of the number of ultrasonic emissions mapped to at least one candidate temperature adjacent to the current temperature.

[0017] In one possible implementation, determining the number of ultrasonic emissions n based on the updated state of the number of ultrasonic emissions mapped to at least one candidate temperature adjacent to the current temperature includes:

[0018] If any of the at least one candidate temperature has a mapped ultrasonic emission count marked as an updated candidate temperature, then the ultrasonic emission count mapped to the candidate temperature whose update status is marked as updated and whose absolute value of the difference with the current temperature is the smallest is determined as the ultrasonic emission count n; if no of the at least one candidate temperature has a mapped ultrasonic emission count marked as an updated candidate temperature, then the ultrasonic emission count mapped to the current temperature is determined as the ultrasonic emission count n.

[0019] In one possible implementation, determining the number of ultrasonic emissions mapped to the current temperature based on the current temperature and the first mapping information includes: determining the number of ultrasonic emissions mapped to the temperature closest to the current temperature in the first mapping information as the number of ultrasonic emissions mapped to the current temperature.

[0020] In one possible implementation, the first mapping information includes a mapping curve between the temperature of the conductive medium and the number of ultrasonic waves emitted; determining the number of ultrasonic waves emitted n based on the current temperature and the first mapping information includes: mapping the current temperature to the number of ultrasonic waves emitted n using the mapping curve.

[0021] In one possible implementation, determining the number of ultrasonic transmissions n based on the current temperature includes: determining the number of ultrasonic transmissions n based on the current temperature and a preset number of high-voltage pulses output to the piezoelectric wafer when transmitting ultrasonic signals.

[0022] In one possible implementation, the fingerprint detection based on the echo signals includes: superimposing n echo signals to obtain a current accumulated sum signal, parsing fingerprint image data based on the current accumulated sum signal, and performing fingerprint detection based on the fingerprint image data.

[0023] According to a second aspect of the embodiments of this application, an ultrasonic fingerprint detection device is provided, comprising: an acquisition module, configured to acquire the current temperature and / or current film application state of a conductive medium, wherein a first side of the conductive medium is attached to an ultrasonic sensor, and a second side of the conductive medium provides a pressing surface; an ultrasonic emission count determination module, configured to determine the number of ultrasonic emission counts n based on the current temperature and / or the current film application state, wherein n is a positive integer; a signal acquisition module, configured to control the ultrasonic sensor to emit n ultrasonic signals to the conductive medium, and receive the echo signal formed after each emitted ultrasonic signal is reflected; and a fingerprint detection module, configured to perform fingerprint detection based on the echo signal.

[0024] According to a third aspect of the present application, an electronic device is provided, comprising: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus; the memory is used to store at least one executable instruction, the executable instruction causing the processor to perform the method described in any embodiment of the first aspect above.

[0025] According to a fourth aspect of the present application, a computer storage medium stores a computer program thereon, which, when executed by a processor, implements the method described in any embodiment of the first aspect above.

[0026] In this embodiment, by obtaining the current temperature of the conductive medium, the number of ultrasonic transmissions n can be determined based on the current temperature. According to the number of ultrasonic transmissions n, the ultrasonic sensor is controlled to transmit ultrasonic signals n times to the conductive medium, and the echo signals formed after each transmitted ultrasonic signal is reflected are received. The received echo signals can be superimposed, and the resulting current sum signal can be used for fingerprint detection. Since the intensity of the current sum signal obtained by superimposing multiple echo signals is significantly improved compared to a single echo signal, the impact of noise on the current sum signal is much smaller than its impact on a single echo signal. Using the current sum signal obtained by superimposing multiple echo signals for fingerprint detection can significantly reduce the impact of noise. In this embodiment, the ultrasonic sensor chip can accumulate the collected multiple echo signals and then output a sum value, i.e., the current sum signal. This current sum signal can be understood as the sum of discrete sampling points in the time dimension. Since the echo signal is discrete in the time dimension, the echo signal can be understood as discrete sampling points. It should be noted that each ultrasonic signal emitted results in the acquisition of one echo signal. Based on this echo signal, a fingerprint image can be obtained. When n ultrasonic signals are emitted, n echo signals are acquired. These n echo signals are accumulated to obtain an enhanced fingerprint image. Fingerprint detection is performed based on the feature points of this enhanced fingerprint image, significantly reducing the impact of noise. Furthermore, in this embodiment, the emitted ultrasonic signal can be adjusted according to the current temperature to ensure that the intensity of the accumulated signal obtained from the superposition of echo signals remains within a certain range under different temperature conditions. This ensures the stability of fingerprint detection accuracy and improves fingerprint detection performance. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0028] Figure 1 is a flowchart of an ultrasonic fingerprint detection method provided in an optional embodiment of this application;

[0029] Figure 2 is a schematic diagram of the propagation path of an ultrasonic signal according to an optional embodiment of this application;

[0030] Figure 3 is a flowchart of another ultrasonic fingerprint detection method provided in an optional embodiment of this application;

[0031] Figure 4 is a schematic diagram of a process for updating mapping information provided in an optional embodiment of this application;

[0032] Figure 5 is a flowchart illustrating a method for determining the number of ultrasonic wave transmissions n according to an optional embodiment of this application;

[0033] Figure 6 is a structural block diagram of an ultrasonic fingerprint detection device provided in an optional embodiment of this application;

[0034] Figure 7 is a schematic diagram of the structure of an electronic device provided in an optional embodiment of this application. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0036] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “an,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0037] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0038] This application provides an ultrasonic fingerprint detection method, apparatus, electronic device, and storage medium to at least partially solve the aforementioned problems existing in related technologies. The method includes: acquiring the current temperature and / or current film application state of a conductive medium, wherein a first side of the conductive medium is attached to an ultrasonic sensor, and a second side of the conductive medium provides a pressing surface. Based on the current temperature and / or current film application state, determining the number of ultrasonic transmissions n; where n is a positive integer. Controlling the ultrasonic sensor to transmit n ultrasonic signals to the conductive medium, and receiving the echo signal formed after each transmitted ultrasonic signal is reflected. Performing fingerprint detection based on the echo signal.

[0039] The ultrasonic fingerprint detection method provided in this application will be described in detail below with reference to the accompanying drawings and Embodiments 1, 2, and 3.

[0040] Example 1: As shown in Figure 1, the ultrasonic fingerprint detection method provided in this embodiment includes:

[0041] S110: Obtain the current temperature of the conductive medium, wherein a first side of the conductive medium is in contact with the ultrasonic sensor, and a second side of the conductive medium provides a pressing surface.

[0042] The ultrasonic sensor can be an under-display ultrasonic sensor or a side-mounted ultrasonic sensor in a mobile phone. Correspondingly, the conductive medium can be the panel of the mobile phone screen or a pressing cover plate on the side of the mobile phone that is attached to the ultrasonic sensor. The first and second sides of the conductive medium can be parallel to each other. Furthermore, in this embodiment, the temperature of the conductive medium can be detected by a temperature sensor in the mobile phone to obtain the current temperature of the conductive medium.

[0043] S120: Determine the number of ultrasonic wave transmissions n based on the current temperature; where n is a positive integer.

[0044] This application embodiment can determine the number of ultrasonic waves emitted for ultrasonic fingerprint detection, i.e., the number of ultrasonic wave emissions, n, based on the current temperature. For example, when the current temperature is 20 degrees Celsius, n can be 30; when the current temperature is 25 degrees Celsius, n can be 38; when the current temperature is 30 degrees Celsius, n can be 38; when the current temperature is 35 degrees Celsius, n can be 45; when the current temperature is 40 degrees Celsius, n can be 42; when the current temperature is 45 degrees Celsius, n can be 38; and when the current temperature is 50 degrees Celsius, n can be 36. Considering the impact of time consumption and power consumption, n does not exceed 200.

[0045] One feasible approach is to preset several temperature ranges and set the number of ultrasonic emissions corresponding to each range. Based on the current temperature's location within that range, the number of ultrasonic emissions (n) corresponding to that range is determined. Alternatively, a mapping curve between temperature and the number of ultrasonic emissions can be preset, and this curve can be used to map the current temperature to the number of ultrasonic emissions (n), etc.

[0046] S130: Controls the ultrasonic sensor to emit n ultrasonic signals into the transmission medium and receives the echo signal formed after each emitted ultrasonic signal is reflected.

[0047] The main components of an ultrasonic sensor are a piezoelectric crystal and two electrodes located on either side of the crystal. When emitting an ultrasonic signal, the ultrasonic sensor outputs a high-voltage pulse to the piezoelectric crystal through one of the electrodes, driving the crystal to generate an ultrasonic signal. When receiving an ultrasonic echo signal, the ultrasonic detection device converts the received echo signal into a voltage signal through the piezoelectric crystal; by acquiring this voltage signal, the characteristics of the echo signal are obtained.

[0048] For example, the signal propagation path of an ultrasonic sensor emitting an ultrasonic signal once is shown as L1-L3 in Figure 2. The intensity P of the echo signal received by the ultrasonic sensor is: P = P0 - ΔP1 - ΔP2 - ΔP3....(Equation 1)

[0049] P0 indicates the intensity of the ultrasonic signal emitted by the ultrasonic sensor; ΔP1 indicates the intensity loss of the ultrasonic signal along the propagation path L1; ΔP2 indicates the intensity loss caused by the ultrasonic signal propagating along L2 to the outside of the conducting medium, including the intensity loss during the process of the ultrasonic signal being reflected back to the conducting medium, and the intensity loss caused by the ultrasonic signal not being reflected back to the conducting medium after propagating to the outside of the conducting medium; ΔP3 indicates the intensity loss of the echo signal along the propagation path L3. It should be understood that the echo signal is the ultrasonic reflected signal formed by the ultrasonic signal being reflected by the second side of the conducting medium.

[0050] S140: Fingerprint detection based on echo signals.

[0051] After receiving n echo signals corresponding to n emitted ultrasonic signals, the ultrasonic sensor can superimpose the n echo signals to obtain an intensity P. nThe current accumulated signal. It should be understood that superimposing n echo signals is equivalent to adding the intensity values ​​of the n echo signals. Sampling one echo signal is completed within a small time range; the intensity value of one echo signal can be understood as the integral value obtained by integrating the received echo signal over its acquisition time range. During the transmission of n ultrasonic signals, each transmitted ultrasonic signal corresponds to the reception of one echo signal. Only after receiving the echo signal of the previous transmitted ultrasonic signal is the next ultrasonic signal transmitted, until all n ultrasonic signals have been transmitted.

[0052] P n The following formula can be used to calculate: P n =n(P0-ΔP1-ΔP2-ΔP3)....(Formula 2)

[0053] Obviously, when n is greater than 1, the strength of the current sum signal is increased several times compared to a single echo signal. At this time, the current sum signal is much less affected by noise than a single echo signal.

[0054] In this embodiment, by obtaining the current temperature of the conductive medium, the number of ultrasonic transmissions n can be determined based on the current temperature. According to the number of ultrasonic transmissions n, the ultrasonic sensor is controlled to transmit ultrasonic signals n times to the conductive medium, and the echo signals formed after each transmitted ultrasonic signal is reflected are received. The received echo signals can be superimposed, and the resulting current sum signal can be used for fingerprint detection. Since the intensity of the current sum signal obtained by superimposing multiple echo signals is significantly improved compared to a single echo signal, the impact of noise on the current sum signal is much smaller than its impact on a single echo signal. Using the current sum signal obtained by superimposing multiple echo signals for fingerprint detection can significantly reduce the impact of noise. In this embodiment, the ultrasonic sensor chip can accumulate the collected multiple echo signals and then output a sum value, i.e., the current sum signal. This current sum signal can be understood as the sum of discrete sampling points in the time dimension. Since the echo signal is discrete in the time dimension, the echo signal can be understood as discrete sampling points. It should be noted that each ultrasonic signal emitted results in the acquisition of one echo signal. Based on this echo signal, a fingerprint image can be obtained. When n ultrasonic signals are emitted, n echo signals are acquired. These n echo signals are accumulated to obtain an enhanced fingerprint image. Fingerprint detection is performed based on the feature points of this enhanced fingerprint image, significantly reducing the impact of noise. Furthermore, in this embodiment, the emitted ultrasonic signal can be adjusted according to the current temperature to ensure that the intensity of the accumulated signal obtained from the superposition of echo signals remains within a certain range under different temperature conditions. This ensures the stability of fingerprint detection accuracy and improves fingerprint detection performance.

[0055] Example 2: This application provides another ultrasonic fingerprint detection method, including:

[0056] The current film application state of the conductive medium is obtained, wherein a first side of the conductive medium is attached to an ultrasonic sensor, and a second side of the conductive medium provides a pressing surface; based on the current film application state, the number of ultrasonic transmissions n is determined, where n is a positive integer; the ultrasonic sensor is controlled to transmit n ultrasonic signals to the conductive medium, and the echo signal formed after each transmitted ultrasonic signal is reflected is received; fingerprint detection is performed based on the echo signal.

[0057] The film application status can include parameters such as whether a film is applied, the film material, and the film thickness, so as to determine the current film application status of the conductive medium by using parameters such as whether a film is applied, the film material, and the film thickness.

[0058] In this embodiment, by acquiring the current film-applied state of the conductive medium, the number of ultrasonic transmissions n can be determined based on the current film-applied state. According to the number of ultrasonic transmissions n, the ultrasonic sensor is controlled to transmit ultrasonic signals n times to the conductive medium, and the echo signals formed after each transmitted ultrasonic signal is reflected are received. The received echo signals can be superimposed, and the resulting current sum signal can be used for fingerprint detection. Since the intensity of the current sum signal obtained by superimposing multiple echo signals is significantly improved compared to a single echo signal, the impact of noise signals on the current sum signal is much smaller than the impact on a single echo signal. Using the current sum signal obtained by superimposing multiple echo signals for fingerprint detection can significantly reduce the impact of noise. In this embodiment, the ultrasonic sensor chip can accumulate the acquired multiple echo signals and then output a sum value, i.e., the current sum signal. This current sum signal can be understood as the sum of discrete sampling points in the time dimension. Since the echo signal is discrete in the time dimension, the echo signal can be understood as discrete sampling points. It should be noted that each ultrasonic signal emitted results in one echo signal, from which a fingerprint image can be obtained. When n ultrasonic signals are emitted, n echo signals are obtained. These n echo signals are accumulated to obtain an enhanced fingerprint image. Fingerprint detection is performed based on the feature points of this enhanced fingerprint image, significantly reducing the impact of noise. Furthermore, in this embodiment, the number of ultrasonic signal emission and echo signal acquisition times can be adjusted according to the current film application state. This ensures that the intensity of the current accumulated signal obtained from the superposition of echo signals remains within a certain range under different film application states, thereby ensuring the stability of fingerprint detection accuracy and improving fingerprint detection performance. This second embodiment is based on the same inventive concept as the first embodiment above. The technical solution of this embodiment is obtained by replacing the reference factor "current temperature / temperature" in the first embodiment with "current film application state / film application state". The specific implementation of this embodiment can be referred to the description of the first embodiment, and will not be repeated here.

[0059] Example 3: This application provides another ultrasonic fingerprint detection method, including:

[0060] The method involves obtaining the current parameter combination of the conductive medium, which includes the current temperature and the current film application status. A first side of the conductive medium is attached to an ultrasonic sensor, and a second side of the conductive medium provides a pressing surface. Based on the current parameter combination, the method determines the number of ultrasonic wave transmissions, n, where n is a positive integer. It controls the ultrasonic sensor to transmit n ultrasonic signals to the conductive medium and receives the echo signals formed after each transmitted ultrasonic signal is reflected. Fingerprint detection is performed based on the echo signals. The film application status may include parameters such as whether a film is applied, the film material, and the film thickness, so that the current temperature and current film application status of the conductive medium can be determined using these parameters. It should be noted that each parameter combination mentioned below in this application includes the corresponding temperature and film application status.

[0061] In this embodiment, by acquiring the current parameter combination, i.e., the current temperature and current film application status of the conductive medium, the number of ultrasonic transmissions n can be determined based on the current temperature and current film application status. According to the number of ultrasonic transmissions n, the ultrasonic sensor is controlled to transmit ultrasonic signals n times to the conductive medium, and the echo signals formed after each transmitted ultrasonic signal is reflected are received. The received echo signals can be superimposed, and the resulting current sum signal can be used for fingerprint detection. Since the intensity of the current sum signal obtained by superimposing multiple echo signals is significantly improved compared to a single echo signal, the impact of noise signals on the current sum signal is much smaller than the impact on a single echo signal. Using the current sum signal obtained by superimposing multiple echo signals for fingerprint detection can significantly reduce the impact of noise. In this embodiment, the ultrasonic sensor chip can accumulate the acquired multiple echo signals and then output a sum value, i.e., the current sum signal. This current sum signal can be understood as the sum of discrete sampling points in the time dimension. Since the echo signal is discrete in the time dimension, the echo signal can be understood as discrete sampling points. It should be noted that each ultrasonic signal emitted results in the acquisition of one echo signal. Based on this echo signal, a fingerprint image can be obtained. When n ultrasonic signals are emitted, n echo signals are acquired. These n echo signals are then summed to obtain an enhanced fingerprint image. Fingerprint detection is performed based on the feature points of this enhanced fingerprint image, significantly reducing the impact of noise. Furthermore, in this embodiment, the number of ultrasonic signal emission and echo signal acquisition times can be adjusted according to the current temperature and the current film application status. This ensures that the intensity of the current accumulated signal obtained from the superposition of echo signals remains within a certain range under different temperature and film application conditions, thereby guaranteeing the stability of fingerprint detection accuracy and improving fingerprint detection performance. This third embodiment is based on the same inventive concept as the first embodiment above. The technical solution of this embodiment is obtained by replacing the reference factor "current temperature / temperature" in the first embodiment with "current temperature / temperature" + "current film application status / film application status". The specific implementation of the technical solution of this embodiment can be referred to the description of the first embodiment, and will not be repeated here.

[0062] As a feasible implementation, the number of electrodes on both sides of the piezoelectric crystal can be increased, thereby increasing the number of high-voltage pulses output from the electrodes to the piezoelectric crystal when emitting ultrasonic signals, thus enhancing the intensity of the emitted ultrasonic signal and the intensity of the received echo signal. If, in Equations 1 and 2, P0 represents the intensity of the ultrasonic signal emitted by the ultrasonic sensor when the number of high-voltage pulses output to the piezoelectric crystal when emitting ultrasonic signals is 1, then the number of high-voltage pulses output to the piezoelectric crystal when emitting ultrasonic signals is Tx. num (Tx num When the integer is positive, the intensity P' of the echo signal corresponding to the ultrasonic signal is: P' = Tx num P0-ΔP1-ΔP2-ΔP3....(Equation 3)

[0063] Tx num The value of Tx is usually set according to the frequency of the high-voltage pulse. For example, when the frequency of the high-voltage pulse output to the piezoelectric crystal is between 10MHz and 12MHz, Tx... num It can be 5; the excitation frequency is between 8MHz and 10MHz, Tx num It can be 6.

[0064] It should be noted that if the number of high-voltage pulses output to the piezoelectric crystal each time an ultrasonic signal is emitted is Tx num If the ultrasonic sensor emits n ultrasonic signals and receives the corresponding n echo signals, then the intensity P′ of the updated cumulative signal is obtained by superimposing the n echo signals. n For: P′ n =n*P′....(Equation 4)

[0065] In some optional embodiments of Embodiment 1, determining the number of ultrasonic transmissions n based on the current temperature includes: determining the number of ultrasonic transmissions n based on the current temperature and a preset number Tx of high-voltage pulses output to the piezoelectric wafer when transmitting ultrasonic signals.

[0066] For example, a mapping relationship between different temperatures (Tx) and the number of ultrasonic waves emitted (n) can be preset, so that the corresponding number of ultrasonic waves emitted (n) can be determined based on the mapping relationship, according to Tx and the current temperature. Alternatively, a mapping relationship between different temperatures (Tx) and the number of ultrasonic waves emitted (n) can be preset, so that the corresponding number of ultrasonic waves emitted (n) can be determined based on the mapping relationship, according to Tx and the current temperature.

[0067] The number of high-voltage pulses is usually limited by the ultrasonic sensor hardware, so the range for adjusting the number of high-voltage pulses is relatively small. In this embodiment, the number of ultrasonic transmissions n is determined based on the current temperature and the preset number of high-voltage pulses Tx output to the piezoelectric crystal when transmitting the ultrasonic signal. This allows for multiple consecutive transmissions of ultrasonic signals and reception of corresponding echo signals while simultaneously transmitting the preset number of high-voltage pulses Tx. This reduces hardware limitations and allows for more flexible enhancement of the strength of the updated accumulated signal, making it easier for the updated accumulated signal to fall within the preset signal strength range.

[0068] In some optional embodiments of Embodiment 2, determining the number of ultrasonic transmissions n based on the current film application state includes: determining the number of ultrasonic transmissions n based on the current film application state and the preset number of high-voltage pulses Tx output to the piezoelectric chip when transmitting ultrasonic signals.

[0069] The number of high-voltage pulses is usually limited by the ultrasonic sensor hardware, so the range for adjusting the number of high-voltage pulses is relatively small. In this embodiment, the number of ultrasonic transmissions n is determined based on the current film application state and the preset number of high-voltage pulses Tx output to the piezoelectric chip when transmitting ultrasonic signals. This allows for multiple consecutive ultrasonic signal transmissions and reception of corresponding echo signals while simultaneously transmitting the preset number of high-voltage pulses Tx, reducing hardware limitations and more flexibly enhancing the strength of the updated cumulative sum signal, making it easier for the updated cumulative sum signal to fall within the preset signal strength range. This optional embodiment of Embodiment Two is based on the same inventive concept as the optional embodiment of Embodiment One above. Replacing the reference factor "current temperature / temperature" in the optional embodiment of Embodiment One with "current film application state / film application state" yields the technical solution of this optional embodiment of Embodiment Two. The specific implementation of this embodiment's technical solution can be found in the relevant description of the optional embodiment of Embodiment One, and will not be repeated here.

[0070] In some optional embodiments of Example 3, the number of ultrasonic transmissions n is determined according to the current parameter combination, including: determining the number of ultrasonic transmissions n based on the current temperature and the current film application state, as well as the preset number of high-voltage pulses Tx output to the piezoelectric chip when transmitting ultrasonic signals.

[0071] The number of high-voltage pulses is usually limited by the ultrasonic sensor hardware, so the range for adjusting the number of high-voltage pulses is relatively small. In this embodiment, the number of ultrasonic transmissions n can be determined based on the current parameter combination, including the current temperature and the current film application state, and the preset number of high-voltage pulses Tx output to the piezoelectric chip when transmitting ultrasonic signals. This allows for multiple consecutive ultrasonic signal transmissions and reception of corresponding echo signals while simultaneously transmitting the preset number of high-voltage pulses Tx, reducing hardware limitations and allowing for more flexible enhancement of the strength of the updated cumulative sum signal, making it easier for the updated cumulative sum signal to fall within the preset signal strength range. This optional embodiment of Embodiment Three is based on the same inventive concept as the optional embodiment of Embodiment One above. Replacing the reference factor "current temperature / temperature" in the optional embodiment of Embodiment One with "current temperature / temperature" + "current film application state / film application state" yields the technical solution of this optional embodiment of Embodiment Three. The specific implementation of this embodiment's technical solution can be found in the relevant description of the optional embodiment of Embodiment One, and will not be repeated here.

[0072] As shown in Figure 3, in some optional embodiments of Example 1, determining the number of ultrasonic wave emissions n based on the current temperature may include:

[0073] S121. Determine the number of ultrasonic waves n based on the current temperature and the first mapping information, wherein the first mapping information is used to indicate the mapping relationship between the temperature of the conductive medium and the number of ultrasonic waves emitted.

[0074] The first mapping information can be a first mapping information table including multiple temperatures and the number of ultrasonic waves emitted at each temperature. The temperature can be a single temperature value or a temperature range, both of which are within the protection scope of the embodiments of this application. The first mapping information can also be a mapping curve between the temperature of the conductive medium and the number of ultrasonic waves emitted, where the temperature of the conductive medium and the number of ultrasonic waves emitted can be the horizontal and vertical coordinates of the midpoint of the mapping curve, respectively, so that the current temperature can be directly mapped to the number of ultrasonic waves emitted, n.

[0075] In this embodiment, the mapping relationship between the temperature of the conductive medium and the number of ultrasonic waves emitted, indicated by the first mapping information, can be used to quickly determine the number of ultrasonic waves emitted, n, without the need for complex calculations, thereby improving the efficiency of fingerprint detection and effectively saving computing power.

[0076] In some optional embodiments of Embodiment 2, determining the number of ultrasonic emissions n based on the current film application state includes: determining the number of ultrasonic emissions n based on the current film application state and second mapping information, wherein the second mapping information is used to indicate the mapping relationship between the film application state of the conductive medium and the number of ultrasonic emissions.

[0077] In this embodiment, the mapping relationship between the film-applying state of the conductive medium indicated by the second mapping information and the number of ultrasonic emission times can be used to quickly determine the number of ultrasonic emission times n, without the need for complex calculations, thereby improving the efficiency of fingerprint detection and effectively saving computing power. This optional embodiment of Embodiment Two is based on the same inventive concept as the optional embodiment of Embodiment One above. By replacing the reference factor "current temperature / temperature" in the optional embodiment of Embodiment One with "current film-applying state / film-applying state," the technical solution of this optional embodiment of Embodiment Two can be obtained. The specific implementation of this embodiment's technical solution can be referred to the relevant description of the optional embodiment of Embodiment One, and will not be repeated here.

[0078] In some optional embodiments of Example 3, determining the number of ultrasonic emissions n based on the current parameter combination includes: determining the number of ultrasonic emissions n based on the current parameter combination and third mapping information, wherein the current parameter combination includes the current temperature and the current film application state, and the third mapping information is used to indicate the mapping relationship between the temperature of the conductive medium, the film application state, and the number of ultrasonic emissions.

[0079] In this embodiment, the mapping relationship between the temperature of the conductive medium, the film application status, and the number of ultrasonic emissions, indicated by the third mapping information, can be used to quickly determine the number of ultrasonic emissions n without complex calculations, thereby improving the efficiency of fingerprint detection and effectively saving computing power. This optional embodiment three is based on the same inventive concept as the optional embodiment one above. By replacing the reference factor "current temperature / temperature" in the optional embodiment one with "current temperature / temperature" + "current film application status / film application status," the technical solution of this optional embodiment three can be obtained. The specific implementation of this embodiment's technical solution can be found in the relevant description of the optional embodiment one, and will not be repeated here.

[0080] As shown in Figure 3, in some optional embodiments of Embodiment 1, the method further includes updating the first mapping information; updating the first mapping information includes:

[0081] S210, Obtain the updated temperature of the conductive medium.

[0082] S220. Based on the updated temperature and the first mapping information, determine the number of ultrasonic wave transmissions m that are mapped to the updated temperature; where m is a positive integer.

[0083] S230: Control the ultrasonic sensor to emit m ultrasonic signals into the conductive medium, and receive the updated echo signal formed after each emitted ultrasonic signal is reflected. The temperature of the conductive medium when the ultrasonic sensor emits m ultrasonic signals is the updated temperature. The m updated echo signals are superimposed to obtain the updated sum signal.

[0084] In this embodiment, the first mapping information can be updated at a fixed time or at a fixed time interval, or it can be updated at a random time. To ensure that the temperature of the conductive medium is the updated temperature when the ultrasonic sensor emits m ultrasonic signals, the updated temperature of the conductive medium can be obtained very close to the time the ultrasonic sensor emits m ultrasonic signals, for example, 0.1 seconds or 0.2 seconds before the emission of m ultrasonic signals. It should be understood that superimposing the m updated echo signals is equivalent to adding the intensity values ​​of the m updated echo signals.

[0085] S240. Update the number of ultrasonic transmissions m based on the strength of the updated cumulative signal and the preset signal strength range.

[0086] It should be understood that the updated sum signal obtained by superimposing the echo signals received by the ultrasonic sensor is an analog quantity, which will eventually be converted into a digital quantity through analog-to-digital conversion. Analog-to-digital conversion has a corresponding operating range; exceeding this range (too strong or too weak) will prevent accurate conversion, resulting in saturation and affecting the accuracy of subsequent fingerprint detection. Therefore, this embodiment can preset a signal strength range based on the operating range of the analog-to-digital conversion, controlling the strength of the updated sum signal obtained by superimposing the echo signals to remain within the operating range of the analog-to-digital conversion.

[0087] When updating the number of ultrasonic emissions m that is mapped to the updated temperature in the first mapping information, the updated cumulative signal obtained by superimposing the updated echo signals can be compared with a preset signal intensity range. When the updated cumulative signal exceeds the preset signal intensity range, the number of ultrasonic emissions mapped to the updated temperature is updated so that the intensity of the updated cumulative signal obtained according to the updated number of ultrasonic emissions is within the preset signal intensity range at the updated temperature.

[0088] It should be noted that S210-S240 can be before or after S110-S140. The embodiments of this application do not limit the order of S210-S240 and S110-S140, as long as both can be performed normally.

[0089] In this embodiment, the updated temperature of the conductive medium can be continuously acquired. Based on the updated temperature and the first mapping information, the number of ultrasonic transmissions m corresponding to the updated temperature is determined. According to the number of ultrasonic transmissions m, the ultrasonic sensor is controlled to transmit ultrasonic signals m times to the conductive medium, and the updated echo signals formed after the ultrasonic signals are reflected each time are received. After the updated echo signals are superimposed to obtain an updated cumulative signal, when the updated cumulative signal exceeds the preset signal strength range, the number of ultrasonic transmissions m corresponding to the updated temperature in the first mapping information is updated. This ensures that when the temperature of the conductive medium is the updated temperature, the intensity of the updated cumulative signal obtained according to the updated number of ultrasonic transmissions can be within the preset signal strength range, thereby improving the accuracy of fingerprint detection.

[0090] In reality, besides temperature, other conditions or user habits can also affect the loss of ultrasonic signals. For example, whether the conductive medium includes a protective film such as a screen protector. When the conductive medium includes a screen protector, the screen protector will cause additional loss to the ultrasonic signal or echo signal. It should be understood that the conductive medium in the embodiments of this application can be composed of multiple parts. For example, the conductive medium may include the mobile phone screen panel and the screen protector attached to the mobile phone screen panel. In this case, the second side of the conductive medium is the side of the screen protector that contacts the finger.

[0091] In this embodiment, by acquiring and updating the temperature in real time and collecting updated echo signals, the number of ultrasonic emissions in the first mapping information is continuously updated. This allows the number of ultrasonic emissions in the first mapping information to change synchronously with the conditions affecting ultrasonic signal loss. Therefore, when the conditions affecting ultrasonic signal loss change, this embodiment can obtain a more accurate number of ultrasonic emissions n based on the updated number of ultrasonic emissions, ensuring that the intensity of the subsequently obtained updated cumulative sum remains within a preset signal intensity range. This guarantees that the method provided by this embodiment is applicable to various usage scenarios or conditions. Furthermore, by continuously updating the number of ultrasonic emissions in the first mapping information, adaptive adjustments can be made to the number of ultrasonic emissions in the first mapping information to accommodate different user habits, thus making the method provided by this embodiment applicable to different users.

[0092] In some optional embodiments of Embodiment 2, the method further includes updating the second mapping information; the updating of the second mapping information includes:

[0093] The process involves: acquiring the updated film-applying state of the conductive medium; determining the number of ultrasonic transmissions *m* corresponding to the updated film-applying state based on the updated film-applying state and the second mapping information; controlling the ultrasonic sensor to transmit *m* ultrasonic signals to the conductive medium and receiving the updated echo signals formed after each transmitted ultrasonic signal is reflected; defining the film-applying state of the conductive medium when the ultrasonic sensor transmits the *m* ultrasonic signals; superimposing the *m* updated echo signals to obtain an updated cumulative sum signal; and updating the number of ultrasonic transmissions *m* based on the intensity of the updated cumulative sum signal and a preset signal intensity range.

[0094] In this embodiment, the updated film-applying state of the conductive medium can be continuously acquired. Based on the updated film-applying state and the second mapping information, the number of ultrasonic transmissions m corresponding to the updated film-applying state is determined. According to the number of ultrasonic transmissions m, the ultrasonic sensor is controlled to transmit m ultrasonic signals to the conductive medium, and the updated echo signals formed after the ultrasonic signals are reflected each time are received. After the updated echo signals are superimposed to obtain an updated cumulative sum signal, when the updated cumulative sum signal exceeds a preset signal strength range, the number of ultrasonic transmissions m corresponding to the updated film-applying state in the second mapping information is updated. This ensures that when the film-applying state of the conductive medium is the updated film-applying state, the intensity of the updated cumulative sum signal obtained according to the updated number of ultrasonic transmissions can be within the preset signal strength range, thereby improving the accuracy of fingerprint detection. The optional embodiment of this embodiment two is based on the same inventive concept as the optional embodiment of embodiment one above. By replacing the reference factor "current temperature / temperature" in the optional embodiment of embodiment one with "current film-applying state / film-applying state", the technical solution of the optional embodiment of this embodiment two can be obtained. The specific implementation of the technical solution of this embodiment can be referred to the relevant description of the optional embodiment of embodiment one, which will not be repeated here.

[0095] In some optional embodiments of Embodiment 3, the method further includes updating the third mapping information; the updating of the third mapping information includes:

[0096] The process involves: acquiring an updated parameter combination for the conductive medium, including an updated temperature and an updated film application state; determining the number of ultrasonic transmissions *m* corresponding to the updated parameter combination based on the updated parameter combination and the third mapping information; controlling the ultrasonic sensor to transmit *m* ultrasonic signals to the conductive medium and receiving the updated echo signals formed after each transmitted ultrasonic signal is reflected, wherein the temperature and film application state of the conductive medium at the time the ultrasonic sensor transmits the *m* ultrasonic signals are the updated temperature and the updated film application state, respectively; superimposing the *m* updated echo signals to obtain an updated cumulative sum signal; and updating the number of ultrasonic transmissions *m* based on the intensity of the updated cumulative sum signal and a preset signal intensity range.

[0097] In this embodiment, the updated parameter combination of the conductive medium can be continuously acquired. Based on the updated parameter combination and the third mapping information, the number of ultrasonic transmissions m corresponding to the updated parameter combination is determined. According to the number of ultrasonic transmissions m, the ultrasonic sensor is controlled to transmit ultrasonic signals m times to the conductive medium, and the updated echo signal formed after the ultrasonic signal is reflected each time is received. After the updated echo signals are superimposed to obtain the updated cumulative signal, when the updated cumulative signal exceeds the preset signal strength range, the number of ultrasonic transmissions m corresponding to the updated temperature and updated film application state in the third mapping information is updated. This ensures that when the temperature and film application state of the conductive medium are the updated temperature and updated film application state in the updated parameter combination, the intensity of the updated cumulative signal obtained according to the updated number of ultrasonic transmissions can be within the preset signal strength range, thereby improving the accuracy of fingerprint detection. The optional embodiment of this embodiment three is based on the same inventive concept as the optional embodiment of embodiment one above. The technical solution of the optional embodiment of this embodiment three is obtained by replacing the reference factor "current temperature / temperature" in the optional embodiment of embodiment one with "current temperature / temperature" + "current film application status / film application status". The specific implementation of the technical solution of this embodiment can be referred to the relevant description of the optional embodiment of embodiment one, which will not be repeated here.

[0098] In some optional embodiments of Example 1, the number of ultrasonic transmissions m is updated based on the strength of the updated accumulated signal and a preset signal strength range, including:

[0099] If the intensity of the updated cumulative signal is within the signal intensity range, then the number of ultrasonic transmissions m is updated to remain m.

[0100] If the intensity of the updated accumulated signal is outside the signal intensity range, the number of updated ultrasonic waves emitted at the updated temperature is determined according to the following formula, and the original number of ultrasonic waves emitted at the updated temperature, m, is updated accordingly: N 更新 =m*P目标 / P 样本

[0101] N 更新 P is used to indicate the number of update ultrasonic waves emitted corresponding to the update temperature. 目标 P is used to indicate the midpoint of a signal strength range. 样本 Used to indicate the strength value of the updated accumulated sum signal;

[0102] Update the number of ultrasonic wave emissions m to the number of ultrasonic wave emissions.

[0103] When the first mapping information is a mapping curve, after updating the number of ultrasonic emissions mapped to the updated temperature in the first mapping information to the updated number of ultrasonic emissions, the updated temperature and N can be... 更新 As a set of "temperature-ultrasonic emission count" samples, it is used to correct the mapping curve to improve the accuracy of the mapping curve.

[0104] In this embodiment of the application, the above formula can be used to determine the number of times the updated ultrasonic waves are emitted corresponding to the updated temperature based on the median value of the preset signal strength range. By updating the number of ultrasonic waves emitted m that is mapped to the updated temperature in the first mapping information to the number of times the updated ultrasonic waves are emitted, the intensity of the updated cumulative sum signal obtained according to the updated ultrasonic waves is located near the median value of the preset signal strength. That is, the updated cumulative sum signal obtained according to the updated ultrasonic waves is more likely to fall into the preset signal strength range, thereby ensuring the effect of analog-to-digital conversion of the updated cumulative sum signal.

[0105] In some optional embodiments of Example 2, updating the number of ultrasonic transmissions m based on the strength of the updated accumulated signal and a preset signal strength range includes:

[0106] If the intensity of the updated cumulative signal is within the signal intensity range, then the number of ultrasonic wave transmissions m is updated to remain at m.

[0107] If the intensity of the updated cumulative signal is outside the signal intensity range, the number of update ultrasonic waves emitted corresponding to the updated film application state is determined according to the following formula: N 更新 =m*P 目标 / P 样本

[0108] N 更新 P is used to indicate the number of times the updated ultrasonic wave is emitted. 目标 P is used to indicate the median value of the signal strength range. 样本 Used to indicate the strength value of the updated accumulated signal;

[0109] Update the number of ultrasonic wave emissions m to the updated number of ultrasonic wave emissions.

[0110] In this embodiment, the above formula can be used to determine the number of ultrasonic waves emitted corresponding to the updated film application state based on the median value of the preset signal strength range. By updating the number of ultrasonic waves emitted m that maps to the updated film application state in the second mapping information to the number of ultrasonic waves emitted, the intensity of the updated cumulative signal obtained according to the number of ultrasonic waves emitted can be located near the median value of the preset signal strength. That is, the updated cumulative signal obtained according to the number of ultrasonic waves emitted can more easily fall within the preset signal strength range, thereby ensuring the effect of analog-to-digital conversion of the updated cumulative signal. The optional embodiment of this embodiment two is based on the same inventive concept as the optional embodiment of embodiment one above. By replacing the reference factor "current temperature / temperature" in the optional embodiment of embodiment one with "current film application state / film application state", the technical solution of the optional embodiment of this embodiment two can be obtained. The specific implementation of the technical solution of this embodiment can be referred to the relevant description of the optional embodiment of embodiment one, which will not be repeated here.

[0111] In some optional embodiments of Example 3, updating the number of ultrasonic transmissions m based on the strength of the updated accumulated signal and a preset signal strength range includes:

[0112] If the intensity of the updated cumulative signal is within the signal intensity range, then the number of ultrasonic wave transmissions m is updated to remain at m.

[0113] If the intensity of the updated cumulative signal is outside the signal intensity range, then the number of update ultrasonic waves emitted corresponding to the update temperature and the update film application state is determined according to the following formula: N 更新 =m*P 目标 / P 样本

[0114] N 更新 P is used to indicate the number of times the updated ultrasonic wave is emitted. 目标 P is used to indicate the median value of the signal strength range. 样本 Used to indicate the strength value of the updated accumulated signal;

[0115] Update the number of ultrasonic wave emissions m to the updated number of ultrasonic wave emissions.

[0116] In this embodiment, the above formula can be used to determine the number of ultrasonic waves emitted corresponding to the updated parameter combination based on the median value of the preset signal strength range. By updating the number of ultrasonic waves emitted m in the third mapping information that maps to the updated temperature and updated film application state of the updated parameter combination to the number of ultrasonic waves emitted, the intensity of the updated cumulative signal obtained according to the number of ultrasonic waves emitted can be located near the median value of the preset signal strength. That is, the updated cumulative signal obtained according to the number of ultrasonic waves emitted can more easily fall within the preset signal strength range, thereby ensuring the effect of analog-to-digital conversion of the updated cumulative signal. The optional embodiment of this embodiment three is based on the same inventive concept as the optional embodiment of embodiment one above. By replacing the reference factor "current temperature / temperature" in the optional embodiment of embodiment one with "current temperature / temperature" + "current film application state / film application state", the technical solution of the optional embodiment of this embodiment three can be obtained. The specific implementation of the technical solution of this embodiment can be referred to the relevant description of the optional embodiment of embodiment one, which will not be repeated here.

[0117] In some optional embodiments of Example 1, the mapping information is updated when there is no finger pressing on the pressing surface. Specifically, when the ultrasonic sensor emits m ultrasonic signals, there is no finger pressing on the pressing surface, and when the updated temperature of the conductive medium is obtained, there is no finger pressing on the pressing surface. However, ultrasonic fingerprint detection is performed when there is finger pressing on the pressing surface. Specifically, when the ultrasonic sensor emits n ultrasonic signals to the conductive medium, there is finger pressing on the pressing surface, and when the current temperature of the conductive medium is obtained, there is finger pressing on the pressing surface.

[0118] When there is no finger pressing on the pressing surface, when the ultrasonic signal propagates to the outside of the conductive medium, most of the ultrasonic signal is reflected back by the interface between the conductive medium and the air, and only a small portion enters the air. The loss of the ultrasonic signal is small, that is, ΔP2 in Equation 1-4 above is small, and the echo signal received by the ultrasonic sensor is large. However, when there is a finger pressing on the pressing surface, when the ultrasonic signal propagates to the outside of the conductive medium, most of the ultrasonic signal will enter the finger, causing a significant loss of the ultrasonic signal. Even if ΔP2 in Equation 1-4 above increases, the echo signal received by the ultrasonic sensor will be smaller. If the first mapping information is updated when there is a finger pressing on the pressing surface, it will lead to an excessive number of ultrasonic transmissions after the updated signal is released. When the finger is lifted, the updated cumulative sum signal obtained by superimposing the collected echo signals will also be excessive. When performing analog-to-digital conversion on the updated cumulative sum signal, saturation is likely to occur, causing the analog-to-digital conversion to fail. Therefore, in this embodiment, the mapping information is updated when there is no finger pressing on the pressing surface. The update timing is after the finger is lifted and the ultrasonic measurement is performed. The mapping information does not need to be updated when the finger is pressing.

[0119] This embodiment updates the first mapping information when there is no finger pressing on the pressing surface. Specifically, when there is no finger pressing on the pressing surface, the ultrasonic sensor is controlled to emit m ultrasonic signals to update the first mapping information, thereby avoiding the above-mentioned problems and ensuring that the analog-to-digital conversion can be performed normally. Obtaining the updated temperature of the conductive medium when there is no finger pressing on the pressing surface avoids the influence of finger temperature on the updated temperature of the conductive medium, reducing the error in obtaining the updated temperature. Furthermore, ultrasonic fingerprint detection is performed when there is a finger pressing on the pressing surface. Specifically, obtaining the current temperature of the conductive medium and the ultrasonic sensor emitting n ultrasonic signals to the conductive medium are both executed when there is a finger pressing on the pressing surface, avoiding the fingerprint detection program when there is no finger pressing, thus saving power consumption.

[0120] In some optional embodiments of Embodiment 2, the second mapping information is updated when there is no finger pressing on the pressing surface. When the ultrasonic sensor emits m ultrasonic signals, there is no finger pressing on the pressing surface. When the updated film state of the conductive medium is obtained, there is no finger pressing on the pressing surface. Alternatively, ultrasonic fingerprint detection is performed when there is finger pressing on the pressing surface. When the ultrasonic sensor emits n ultrasonic signals to the conductive medium, there is finger pressing on the pressing surface. When the current film state of the conductive medium is obtained, there is finger pressing on the pressing surface.

[0121] This embodiment updates the second mapping information when there is no finger pressing on the pressing surface. Specifically, when there is no finger pressing on the pressing surface, the ultrasonic sensor is controlled to emit m ultrasonic signals to update the second mapping information, thereby avoiding the above-mentioned problems and ensuring that the analog-to-digital conversion can be performed normally. Obtaining the updated film state of the conductive medium when there is no finger pressing on the pressing surface avoids the finger's film state affecting the updated film state of the conductive medium, reducing the error in obtaining the updated film state. Furthermore, ultrasonic fingerprint detection is performed when there is a finger pressing on the pressing surface. Specifically, obtaining the current film state of the conductive medium and the ultrasonic sensor emitting n ultrasonic signals to the conductive medium are both executed when there is a finger pressing on the pressing surface, avoiding the fingerprint detection program when there is no finger pressing, thus saving power. The optional embodiment of this embodiment two is based on the same inventive concept as the optional embodiment of embodiment one above. By replacing the reference factor "current temperature / temperature" in the optional embodiment of embodiment one with "current film application status / film application status", the technical solution of the optional embodiment of this embodiment two can be obtained. The specific implementation of the technical solution of this embodiment can be referred to the relevant description of the optional embodiment of embodiment one, which will not be repeated here.

[0122] In some optional embodiments of Embodiment 3, the third mapping information is updated when there is no finger pressing on the pressing surface. Specifically, when the ultrasonic sensor emits m ultrasonic signals, there is no finger pressing on the pressing surface. When the updated temperature of the conductive medium and the updated film application status are obtained, there is no finger pressing on the pressing surface. Alternatively, ultrasonic fingerprint detection is performed when there is finger pressing on the pressing surface. Specifically, when the ultrasonic sensor emits n ultrasonic signals to the conductive medium, there is finger pressing on the pressing surface. When the current temperature of the conductive medium and the current film application status are obtained, there is finger pressing on the pressing surface.

[0123] This embodiment updates the third mapping information when there is no finger pressing on the pressing surface. Specifically, when there is no finger pressing on the pressing surface, the ultrasonic sensor is controlled to emit m ultrasonic signals to update the third mapping information, thereby avoiding the above-mentioned problems and ensuring that the analog-to-digital conversion can be performed normally. In addition, when there is no finger pressing on the pressing surface, the update temperature of the conductive medium and the update film status are obtained, which can avoid the influence of finger temperature on the update temperature of the conductive medium and reduce the error in obtaining the update temperature. Furthermore, when there is a finger pressing on the pressing surface, ultrasonic fingerprint detection is performed. Specifically, the current temperature of the conductive medium, the current film status, and the ultrasonic sensor emitting n ultrasonic signals to the conductive medium are all executed when there is a finger pressing on the pressing surface. This avoids executing the fingerprint detection program when there is no finger pressing, thus saving power consumption. The optional embodiment of this embodiment three is based on the same inventive concept as the optional embodiment of embodiment one above. The technical solution of the optional embodiment of this embodiment three is obtained by replacing the reference factor "current temperature / temperature" in the optional embodiment of embodiment one with "current temperature / temperature" + "current film application status / film application status". The specific implementation of the technical solution of this embodiment can be referred to the relevant description of the optional embodiment of embodiment one, which will not be repeated here.

[0124] In some optional embodiments of Embodiment 1, the first mapping information includes the temperature of the conductive medium, the number of ultrasonic waves emitted that correspond to the temperature of the conductive medium, and the update status of the number of ultrasonic waves emitted.

[0125] The temperature of the conductive medium in the first mapping information can be a single temperature value or a temperature range. For example, the first mapping information can be Table 1 below:

[0126] Table 1: First Mapping Information Table

[0127] In Table 1, a, b, c, d, and e represent different ultrasonic emission counts, and their values ​​are positive integers. In this embodiment, by reducing the temperature intervals in Table 1, the granularity of the updated temperature is decreased, thereby improving the accuracy of determining the ultrasonic emission count n based on the updated temperature. This allows the first mapping information to be better applied to ultrasonic sensors operating at various temperatures.

[0128] For ease of understanding, the process of updating the first mapping information in the embodiment of this application will be illustrated below with reference to FIG4.

[0129] As shown in Figure 4, after obtaining m update echo signals through S401, S402 can be executed to determine the intensity of the update sum signal obtained by superimposing the m update echo signals, and S403 can be executed to determine whether the intensity of the update sum signal is within the preset signal intensity range. If the determination result is yes, then S404 is executed to update the number of ultrasonic transmissions mapped to the update temperature in the first mapping information to maintain m, and the update status of the number of ultrasonic transmissions mapped to the update temperature is determined to be updated. If the determination result is no, then S405 is executed to calculate the number of update ultrasonic transmissions corresponding to the update temperature. For example, the number of update ultrasonic transmissions N corresponding to the update temperature can be calculated according to the formula above. 更新 The number of ultrasonic emissions mapped to the updated temperature in the first mapping information is updated to the number of ultrasonic emissions, and the update status of the number of ultrasonic emissions mapped to the updated temperature is determined to be updated.

[0130] In this embodiment, it can be determined whether the intensity of the updated cumulative sum signal is within a preset signal intensity range. If the intensity of the updated cumulative sum signal is no longer within the preset signal intensity range, the number of ultrasonic transmissions in the first mapping information is updated so that the intensity of the corresponding updated cumulative sum signal returns to the preset signal intensity range. The update status of the number of ultrasonic transmissions is then determined to be updated, indicating that the number of ultrasonic transmissions has higher timeliness compared to when it was not updated. Alternatively, if the intensity of the updated cumulative sum signal is within the preset signal intensity range, the corresponding number of ultrasonic transmissions can be kept at its original value, and the update status of the number of ultrasonic transmissions can be determined to be updated, indicating that the number of ultrasonic transmissions also has high timeliness.

[0131] Optionally, the number of ultrasonic wave transmissions n is determined based on the current temperature and the first mapping information, including:

[0132] Based on the current temperature and the first mapping information, determine the number of ultrasonic wave emissions that correspond to the current temperature.

[0133] As an alternative implementation, the number of ultrasonic emissions mapped to the temperature closest to the current temperature in the first mapping information can be determined as the number of ultrasonic emissions mapped to the current temperature.

[0134] Referring to Table 1, for example, if the current temperature is 43 degrees, the number of ultrasonic emissions 'd' mapped to 45 degrees can be determined as the number of ultrasonic emissions mapped to the current temperature. Furthermore, if there are two temperatures in the first mapping information that are closest to the current temperature, the number of ultrasonic emissions mapped to the lower temperature can be selected as the number of ultrasonic emissions mapped to the current temperature, or the number of ultrasonic emissions mapped to the higher temperature can be selected as the number of ultrasonic emissions mapped to the current temperature; both are within the protection scope of the embodiments of this application.

[0135] In this embodiment, when the current temperature is not equal to the temperature in the first mapping information, the number of ultrasonic emissions in the first mapping information that maps to the temperature closest to the current temperature is determined as the number of ultrasonic emissions mapped to the current temperature. This allows for a simple and quick determination of the number of ultrasonic emissions mapped to the current temperature, thereby improving the efficiency of ultrasonic fingerprint detection.

[0136] Of course, other suitable methods can also be used in the embodiments of this application to determine the number of ultrasonic emissions mapped to the current temperature. For example, the current temperature can be interpolated from the temperatures included in the first mapping information, and the number of ultrasonic emissions mapped to the current temperature can be determined by interpolation. All of these are within the protection scope of the embodiments of this application.

[0137] If the update status of the number of ultrasonic emissions mapped to the current temperature in the first mapping information is marked as updated, then the number of ultrasonic emissions mapped to the current temperature is determined as the number of ultrasonic emissions n.

[0138] If the update status of the number of ultrasonic emissions mapped to the current temperature in the first mapping information is not marked as updated, then the number of ultrasonic emissions n is determined according to the update status of the number of ultrasonic emissions mapped to at least one candidate temperature adjacent to the current temperature in the first mapping information.

[0139] Candidate temperatures can be several temperatures in the first mapping information that are close to the current temperature. For example, they can be the temperatures that are the closest to the current temperature but not the ones that are the smallest (e.g., 5 or 7, etc., which can be preset as needed).

[0140] In this embodiment, the first mapping information includes the temperature of the conductive medium, the number of ultrasonic emissions mapped to the temperature of the conductive medium, and the update status of the number of ultrasonic emissions. Specifically, when determining the number of ultrasonic emissions n, the number of ultrasonic emissions mapped to the current temperature can be determined based on the current temperature and the first mapping information. If the update status of the number of ultrasonic emissions mapped to the current temperature is marked as updated, then the number of ultrasonic emissions mapped to the current temperature is determined as the number of ultrasonic emissions n. If the update status of the number of ultrasonic emissions mapped to the current temperature is not marked as updated, then the number of ultrasonic emissions n is determined based on the update status of the number of ultrasonic emissions mapped to at least one candidate temperature adjacent to the current temperature. This approach utilizes the data update status in the first mapping information to select the most updated number of ultrasonic emissions as the number of ultrasonic emissions n, ensuring the timeliness of the number of ultrasonic emissions n and preventing untimely updates from affecting the fingerprint detection effect.

[0141] In some optional embodiments of Embodiment 2, the second mapping information includes the film-coating state of the conductive medium, the number of ultrasonic waves emitted that correspond to the film-coating state of the conductive medium, and the update status of the number of ultrasonic waves emitted.

[0142] The step of determining the number of ultrasonic emissions n based on the current film application status and the second mapping information includes:

[0143] Based on the current film application status and the second mapping information, determine the number of ultrasonic wave emissions that correspond to the current film application status;

[0144] If the update status of the number of ultrasonic emissions mapped to the current film application state is marked as updated, then the number of ultrasonic emissions mapped to the current film application state is determined as the number of ultrasonic emissions n.

[0145] If the update status of the number of ultrasonic emissions mapped to the current film application state is not marked as updated, then the number of ultrasonic emissions n is determined based on the update status of the number of ultrasonic emissions mapped to at least one candidate film application state adjacent to the current film application state.

[0146] In this embodiment, the second mapping information includes the film-applying state of the conductive medium, the number of ultrasonic emissions mapped to the film-applying state of the conductive medium, and the update status of the number of ultrasonic emissions. Specifically, when determining the number of ultrasonic emissions n, the number of ultrasonic emissions mapped to the current film-applying state can be determined based on the current film-applying state and the second mapping information. When the update status of the number of ultrasonic emissions mapped to the current film-applying state is marked as updated, the number of ultrasonic emissions mapped to the current film-applying state is determined as the number of ultrasonic emissions n. When the update status of the number of ultrasonic emissions mapped to the current film-applying state is not marked as updated, the number of ultrasonic emissions n is determined based on the update status of the number of ultrasonic emissions mapped to at least one candidate film-applying state adjacent to the current film-applying state. By utilizing the data update status in the second mapping information, updated ultrasonic emissions can be selected as the number of ultrasonic emissions n as much as possible, ensuring the timeliness of the number of ultrasonic emissions n and avoiding the impact of untimely updates on the number of ultrasonic emissions on the fingerprint detection effect. The optional embodiment of this embodiment two is based on the same inventive concept as the optional embodiment of embodiment one above. By replacing the reference factor "current temperature / temperature" in the optional embodiment of embodiment one with "current film application status / film application status", the technical solution of the optional embodiment of this embodiment two can be obtained. The specific implementation of the technical solution of this embodiment can be referred to the relevant description of the optional embodiment of embodiment one, which will not be repeated here.

[0147] In some optional embodiments of Embodiment 3, the third mapping information includes the temperature of the conductive medium, the film-applying state, the number of ultrasonic waves emitted that map to the temperature of the conductive medium and the film-applying state, and the update status of the number of ultrasonic waves emitted.

[0148] Determining the number of ultrasonic transmissions n based on the current parameter combination and the third mapping information includes:

[0149] Based on the current parameter combination and the third mapping information, determine the number of ultrasonic wave emissions mapped to the current parameter combination;

[0150] If the update status of the number of ultrasonic emissions mapped to the current parameter combination is marked as updated, then the number of ultrasonic emissions mapped to the parameter combination is determined as the number of ultrasonic emissions n.

[0151] If the update status of the number of ultrasonic emissions mapped to the parameter combination is not marked as updated, the number of ultrasonic emissions n is determined based on the update status of the number of ultrasonic emissions mapped to at least one candidate parameter combination adjacent to the current parameter combination; wherein, the candidate parameter combination includes candidate temperature and candidate film application state.

[0152] In this embodiment, the third mapping information includes the temperature of the conductive medium, the film application status, the number of ultrasonic emissions mapped to the temperature and film application status, and the update status of the number of ultrasonic emissions. Specifically, when determining the number of ultrasonic emissions n, the number of ultrasonic emissions mapped to the current parameter combination can be determined based on the current temperature, the current film application status, and the third mapping information. When the update status of the number of ultrasonic emissions mapped to the current parameter combination is marked as updated, the number of ultrasonic emissions mapped to the current parameter combination is determined as the number of ultrasonic emissions n. When the update status of the number of ultrasonic emissions mapped to the current parameter combination is not marked as updated, the number of ultrasonic emissions n is determined based on the update status of the number of ultrasonic emissions of at least one candidate parameter combination adjacent to the current parameter combination. By utilizing the data update status in the third mapping information, updated ultrasonic emissions can be selected as the number of ultrasonic emissions n as much as possible, ensuring the timeliness of the number of ultrasonic emissions n and avoiding the impact of untimely updates on the number of ultrasonic emissions on the fingerprint detection effect. The optional embodiment of this embodiment three is based on the same inventive concept as the optional embodiment of embodiment one above. The technical solution of the optional embodiment of this embodiment three is obtained by replacing the reference factor "current temperature / temperature" in the optional embodiment of embodiment one with "current temperature / temperature" + "current film application status / film application status". The specific implementation of the technical solution of this embodiment can be referred to the relevant description of the optional embodiment of embodiment one, which will not be repeated here.

[0153] In some optional embodiments of Example 1, determining the number of ultrasonic emissions n based on the updated state of the number of ultrasonic emissions mapped to at least one candidate temperature adjacent to the current temperature includes:

[0154] If at least one candidate temperature has a mapped ultrasonic emission count marked as an updated candidate temperature, then the ultrasonic emission count n is determined by mapping the updated ultrasonic emission count to the candidate temperature with the smallest absolute value of the difference between the updated and current temperatures. If at least one candidate temperature does not have a mapped ultrasonic emission count marked as an updated candidate temperature, then the ultrasonic emission count mapped to the current temperature is determined as the ultrasonic emission count n.

[0155] It should be understood that there can be multiple candidate temperatures, and the update status of the number of ultrasonic emissions for each candidate temperature can be determined based on the first mapping information.

[0156] When only one ultrasonic emission count mapped to a candidate temperature has an updated status, that ultrasonic emission count mapped to the candidate temperature can be determined as the ultrasonic emission count n.

[0157] When there are multiple candidate temperature mappings whose ultrasonic emission counts are updated, the ultrasonic emission count n can be determined by the candidate temperature mapping whose update status is marked as updated and whose absolute value of the difference with the current temperature is the smallest.

[0158] Of course, other suitable methods can be used to determine the number of ultrasonic emissions n. For example, when the update status of the number of ultrasonic emissions for multiple candidate temperature mappings is updated, the average value of the number of ultrasonic emissions for these candidate temperature mappings can be taken and the average value can be determined as the number of ultrasonic emissions n.

[0159] For ease of understanding, the process of determining the number of ultrasonic transmissions n in the embodiments of this application will be illustrated below with reference to FIG5.

[0160] As shown in Figure 5, after obtaining the current temperature in S501, S502 can be executed to determine whether the number of ultrasonic emissions mapped to the current temperature in the first mapping information has been marked as updated. If the determination result is yes, then S503 is executed to determine the number of ultrasonic emissions mapped to the current temperature as the number of ultrasonic emissions n. If the determination result is no, then S504 can be executed to determine whether the update status of the number of ultrasonic emissions mapped to at least one candidate temperature adjacent to the current temperature in the first mapping information is updated. If the determination result is yes, then S505 is executed to determine the number of ultrasonic emissions n of the candidate temperature mapped to which the mapped ultrasonic emissions are marked as updated and which has the smallest absolute value of the difference with the current temperature. If the determination result is no, then S503 is executed to determine the number of ultrasonic emissions n of the current temperature.

[0161] In this embodiment, when at least one candidate temperature has a mapped ultrasonic emission count marked as an updated candidate temperature, the ultrasonic emission count n can be determined based on the ultrasonic emission count mapped to the updated candidate temperature. This ensures that the updated ultrasonic emission count n is selected as the ultrasonic emission count n, guaranteeing its timeliness and avoiding fingerprint detection errors due to untimely updates. Furthermore, even when no mapped ultrasonic emission count is marked as an updated candidate temperature in at least one candidate temperature, the ultrasonic emission count mapped to the current temperature can still be determined as the ultrasonic emission count n, thus ensuring the smooth operation of ultrasonic fingerprint detection.

[0162] In some optional embodiments of Example 2, determining the number of ultrasonic emissions n based on the updated state of the number of ultrasonic emissions mapped to at least one candidate film application state adjacent to the current film application state includes:

[0163] If any candidate film application state has a mapped ultrasonic emission count that is marked as an updated candidate film application state, then the ultrasonic emission count mapped to the candidate film application state whose updated state of mapped ultrasonic emission count is marked as updated and whose absolute value of the difference between the updated state and the current film application state is the smallest is determined as the ultrasonic emission count n. For example, each parameter in the candidate film application state can be used as its coordinate component, the parameter value in the current film application state can be used as its coordinate component, and the Euclidean distance or Chebyshev distance between the candidate film application state and the current film application state can be used as the difference between the two. Of course, other methods can also be used to determine the difference between the candidate film application state and the current film application state, all of which are within the protection scope of the embodiments of this application.

[0164] If no corresponding ultrasonic emission count is marked as an updated candidate film application state in at least one candidate film application state, then the ultrasonic emission count mapped to the current film application state is determined as the ultrasonic emission count n.

[0165] In this embodiment, when at least one candidate film application state has a mapped ultrasonic emission count marked as an updated candidate film application state, the ultrasonic emission count n can be determined based on the ultrasonic emission count mapped to the updated candidate film application state. This ensures that the updated ultrasonic emission count is selected as the ultrasonic emission count n, guaranteeing its timeliness and avoiding fingerprint detection errors due to untimely updates. Furthermore, even when no mapped ultrasonic emission count is marked as an updated candidate film application state in at least one candidate film application state, the ultrasonic emission count mapped to the current film application state can still be determined as the ultrasonic emission count n, ensuring the smooth operation of ultrasonic fingerprint detection. This optional embodiment of Embodiment Two is based on the same inventive concept as the optional embodiment of Embodiment One above. Replacing the reference factor "current temperature / temperature" in the optional embodiment of Embodiment One with "current film application state / film application state" yields the technical solution of this optional embodiment of Embodiment Two. The specific implementation of this embodiment's technical solution can be found in the relevant description of the optional embodiment of Embodiment One, and will not be repeated here.

[0166] In some optional embodiments of Embodiment 3, determining the number of ultrasonic emissions n based on the update status of the number of ultrasonic emissions mapped to at least one candidate parameter combination adjacent to the current parameter combination includes:

[0167] If any candidate parameter combination has a mapped ultrasonic emission count that is marked as updated, then the ultrasonic emission count mapped to the candidate parameter combination whose updated state of the mapped ultrasonic emission count is marked as updated and whose absolute value of the difference with the current parameter combination is the smallest is determined as the ultrasonic emission count n. For example, each parameter in the candidate parameter combination can be used as its coordinate component, the parameter value in the current parameter combination can be used as its coordinate component, and the Euclidean distance or Chebyshev distance between the candidate parameter combination and the current parameter combination can be used as the difference between the two. Of course, other methods can also be used to determine the difference between the candidate parameter combination and the current parameter combination, all of which are within the protection scope of the embodiments of this application.

[0168] If no mapped ultrasonic emission count is marked as an updated candidate parameter combination in at least one candidate parameter combination, then the ultrasonic emission count mapped to the current parameter combination is determined as the ultrasonic emission count n.

[0169] In this embodiment, when at least one candidate parameter combination has a mapped ultrasonic emission count marked as an updated candidate parameter combination, the ultrasonic emission count n can be determined based on the ultrasonic emission count mapped to the updated candidate parameter combination. This ensures that the updated ultrasonic emission count is selected as the ultrasonic emission count n, guaranteeing its timeliness and avoiding fingerprint detection errors due to untimely updates. Furthermore, even when no mapped ultrasonic emission count is marked as an updated candidate parameter combination in at least one candidate parameter combination, the ultrasonic emission count mapped to the current parameter combination can still be determined as the ultrasonic emission count n, ensuring the smooth operation of ultrasonic fingerprint detection. This optional embodiment three is based on the same inventive concept as the optional embodiment one above. The technical solution of this optional embodiment three is obtained by replacing the reference factor "current temperature / temperature" in the optional embodiment one with "current temperature / temperature" + "current film application status / film application status". The specific implementation of this embodiment's technical solution can be found in the relevant description of the optional embodiment one, and will not be repeated here.

[0170] In some optional embodiments of Embodiment 2, determining the number of ultrasonic emissions mapped to the current film application state based on the current film application state and the second mapping information includes:

[0171] The number of ultrasonic emissions mapped to the film application state closest to the current film application state in the second mapping information is determined as the number of ultrasonic emissions mapped to the current film application state. The film application state closest to the current film application state can be determined by calculating the film application state with the smallest Euclidean distance or Chebyshev distance from the current film application state. The calculation method for Euclidean distance or Chebyshev distance can be found in relevant technologies and will not be elaborated here.

[0172] In this embodiment, when the current film application state is not equal to the film application state in the second mapping information, the number of ultrasonic emission counts in the second mapping information that maps to the film application state closest to the current film application state is determined as the number of ultrasonic emission counts mapped to the current film application state. This allows for a simple and quick determination of the number of ultrasonic emission counts mapped to the current film application state, improving the efficiency of ultrasonic fingerprint detection. This optional embodiment of Embodiment Two is based on the same inventive concept as the optional embodiment of Embodiment One above. Replacing the reference factor "current temperature / temperature" in the optional embodiment of Embodiment One with "current film application state / film application state" yields the technical solution of this optional embodiment of Embodiment Two. The specific implementation of this embodiment's technical solution can be found in the relevant description of the optional embodiment of Embodiment One, and will not be repeated here.

[0173] In some optional embodiments of Embodiment 3, determining the number of ultrasonic emissions mapped to the current parameter combination based on the current parameter combination and the third mapping information includes:

[0174] The number of ultrasonic transmissions mapped to the parameter combination closest to the current parameter combination in the third mapping information is determined as the number of ultrasonic transmissions mapped to the current parameter combination. The parameter combination closest to the current parameter combination can be determined by calculating the parameter combination with the smallest Euclidean distance or Chebyshev distance. The calculation method for Euclidean distance or Chebyshev distance can be found in relevant technologies and will not be elaborated here.

[0175] In this embodiment, when the current parameter combination is not equal to the parameter combination in the third mapping information, the number of ultrasonic emissions mapped to the parameter combination closest to the current parameter combination in the third mapping information is determined as the number of ultrasonic emissions mapped to the current parameter combination. This allows for a simple and quick determination of the number of ultrasonic emissions mapped to the current parameter combination, improving the efficiency of ultrasonic fingerprint detection. This optional embodiment of Embodiment Three is based on the same inventive concept as the optional embodiment of Embodiment One above. The technical solution of this optional embodiment of Embodiment Three is obtained by replacing the reference factor "current temperature / temperature" in the optional embodiment of Embodiment One with "current temperature / temperature" + "current film application status / film application status". The specific implementation of this embodiment's technical solution can be found in the relevant description of the optional embodiment of Embodiment One, and will not be repeated here.

[0176] In some optional embodiments of Example 1, the first mapping information includes a mapping curve between the temperature of the conductive medium and the number of ultrasonic waves emitted. Determining the number of ultrasonic waves emitted, n, based on the current temperature and the first mapping information includes mapping the current temperature to the number of ultrasonic waves emitted, n, using the mapping curve.

[0177] It should be understood that the mapping curve can exist in the form of a graph or a functional relationship, both of which are within the protection scope of the embodiments of this application. When determining the number of ultrasonic emissions n, only the current temperature needs to be input, and the number of ultrasonic emissions n can be obtained using the fitted curve.

[0178] In this embodiment, the first mapping information includes a mapping curve between the temperature of the conductive medium and the number of ultrasonic waves emitted. Through a continuous mapping curve, the current temperature value can be directly mapped to the number of ultrasonic waves emitted, n, which can more accurately determine the number of ultrasonic waves emitted, n, corresponding to the current temperature and improve the accuracy of fingerprint detection.

[0179] As a feasible implementation, a default mapping curve can be provided. Then, during the ultrasonic fingerprint detection process, the number of ultrasonic emissions at various temperatures of the conductive medium, ensuring the updated cumulative signal falls within a preset signal strength range, is continuously recorded to obtain multiple sets of "temperature-ultrasonic emission count" samples. These multiple sets of "temperature-ultrasonic emission count" samples are then used to continuously correct the mapping curve. As the number of "temperature-ultrasonic emission count" samples increases, the accuracy of the mapping curve will also continuously improve.

[0180] In some optional embodiments of Embodiment 2, the second mapping information includes a mapping curve between the film-coating state of the conductive medium and the number of ultrasonic wave emissions;

[0181] The step of determining the number of ultrasonic emissions n based on the current film application status and the second mapping information includes:

[0182] The current film application state is mapped to the number of ultrasonic wave emissions n using the mapping curve.

[0183] In this embodiment, the second mapping information includes a mapping curve between the film application state of the conductive medium and the number of ultrasonic emissions. Through a continuous mapping curve, the current film application state can be directly mapped to the number of ultrasonic emissions n, enabling a more accurate determination of the number of ultrasonic emissions n corresponding to the current film application state and improving the accuracy of fingerprint detection. This optional embodiment of Embodiment Two is based on the same inventive concept as the optional embodiment of Embodiment One above. Replacing the reference factor "current temperature / temperature" in the optional embodiment of Embodiment One with "current film application state / film application state" yields the technical solution of this optional embodiment of Embodiment Two. The specific implementation of this embodiment's technical solution can be found in the relevant description of the optional embodiment of Embodiment One, and will not be repeated here.

[0184] In some optional embodiments of Embodiment 3, the third mapping information includes a mapping curve between the temperature of the conductive medium, the film-attachment state, and the number of ultrasonic wave emissions;

[0185] Determining the number of ultrasonic transmissions n based on the current parameter combination and the third mapping information includes:

[0186] The current parameter combination, including the current temperature and the current film application status, is mapped to the number of ultrasonic waves n using the mapping curve.

[0187] In this embodiment, the third mapping information includes a mapping curve between the temperature of the conductive medium, the film application state, and the number of ultrasonic emissions. Through a continuous mapping curve, the current parameter combination, including the current temperature and the current film application state, can be directly mapped to the number of ultrasonic emissions n, enabling a more accurate determination of the number of ultrasonic emissions n corresponding to the current parameter combination and improving the accuracy of fingerprint detection. This optional embodiment of Embodiment Three is based on the same inventive concept as the optional embodiment of Embodiment One above. Replacing the reference factor "current temperature / temperature" in the optional embodiment of Embodiment One with "current temperature / temperature" + "current film application state / film application state" yields the technical solution of this optional embodiment of Embodiment Three. The specific implementation of this embodiment's technical solution can be found in the relevant description of the optional embodiment of Embodiment One, and will not be repeated here.

[0188] In some optional embodiments of Examples 1, 2, and 3, the fingerprint detection based on the echo signal includes:

[0189] The current accumulated sum signal is obtained by superimposing the n echo signals, the fingerprint image data is analyzed based on the current accumulated sum signal, and fingerprint detection is performed based on the fingerprint image data.

[0190] In this embodiment, the ultrasonic sensor chip can accumulate multiple acquired echo signals and then output a sum value, i.e., the current accumulated sum signal. Specifically, each time an ultrasonic signal is emitted, an echo signal can be acquired. Based on this echo signal, a fingerprint image data can be obtained. Similarly, based on the accumulated current sum signal, an enhanced fingerprint image data can be obtained. Fingerprint detection can be performed based on the feature points of this enhanced fingerprint image data, which can significantly reduce the impact of noise.

[0191] According to a second aspect of the embodiments of this application, as shown in FIG6, an ultrasonic fingerprint detection device is provided, comprising:

[0192] The acquisition module 601 is used to acquire the current temperature and / or current film application status of the conductive medium, wherein a first side of the conductive medium is attached to the ultrasonic sensor, and a second side of the conductive medium provides a pressing surface.

[0193] The ultrasonic emission count determination module 602 is used to determine the number of ultrasonic emissions n based on the current temperature and / or the current film application status.

[0194] The signal acquisition module 603 is used to control the ultrasonic sensor to emit n ultrasonic signals to the transmission medium and to receive the echo signal formed after each emitted ultrasonic signal is reflected, where n is equal to the number of ultrasonic emission times.

[0195] The fingerprint detection module 604 is used to perform fingerprint detection based on the echo signal.

[0196] The ultrasonic fingerprint detection device of this embodiment is based on the same inventive concept as the aforementioned ultrasonic fingerprint detection method embodiments, and is used to implement the corresponding ultrasonic fingerprint detection methods in the aforementioned multiple method embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here. In addition, the functional implementation of each unit in the ultrasonic fingerprint detection device of this embodiment can refer to the description of the corresponding part in the aforementioned method embodiments, which will also not be repeated here.

[0197] According to a third aspect of the embodiments of this application, an electronic device is provided. The specific embodiments of this application do not limit the specific implementation of the electronic device.

[0198] As shown in Figure 7, the electronic device may include: a processor 702, a communications interface 704, a memory 706, and a communications bus 708.

[0199] in:

[0200] The processor 702, communication interface 704, and memory 706 communicate with each other via communication bus 708.

[0201] Communication interface 704 is used to communicate with other electronic devices or servers.

[0202] The processor 702 is used to execute program 710, which can specifically execute the relevant steps in the above-described ultrasonic fingerprint detection method embodiment.

[0203] Specifically, program 710 may include program code, which includes executable instructions, which may be computer operation instructions.

[0204] The processor 702 may be a CPU, an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application. The smart device includes one or more processors, which may be processors of the same type, such as one or more CPUs; or processors of different types, such as one or more CPUs and one or more ASICs.

[0205] Memory 706 is used to store program 710. Memory 706 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0206] The program 710 may include multiple executable instructions. Specifically, the program 710 can use multiple executable instructions to cause the processor 702 to perform the operation corresponding to the ultrasonic fingerprint detection method described in any of the foregoing multiple method embodiments.

[0207] The specific implementation of each step in program 710 can be found in the corresponding steps and units described in the above method embodiments, and has corresponding beneficial effects, which will not be repeated here. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the devices and modules described above can be referred to the corresponding process descriptions in the foregoing method embodiments, and will not be repeated here.

[0208] According to a fourth aspect of the embodiments of this application, a computer storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the method described in any of the foregoing method embodiments. The computer storage medium includes, but is not limited to, compact disc read-only memory (CD-ROM), random access memory (RAM), floppy disk, hard disk, or magneto-optical disk.

[0209] This application also provides a computer program product, including computer instructions that instruct a computing device to perform an operation corresponding to any of the ultrasonic fingerprint detection methods in the above-described multiple method embodiments.

[0210] It should be noted that, depending on the implementation needs, the various components / steps described in the embodiments of this application can be broken down into more components / steps, or two or more components / steps or parts of the operation of components / steps can be combined into new components / steps to achieve the purpose of the embodiments of this application.

[0211] Those skilled in the art will recognize that the units and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this application.

[0212] The above embodiments are only used to illustrate the embodiments of this application, and are not intended to limit the embodiments of this application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of this application. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of this application, and the patent protection scope of the embodiments of this application should be defined by the claims.

Claims

1. An ultrasonic fingerprint detection method, characterized by, The method comprises: obtaining a current temperature and / or a current film-attached state of a conductive medium, wherein a first side of the conductive medium is attached to an ultrasonic sensor, and a second side of the conductive medium provides a pressing surface; determining an ultrasonic emission number n according to the current temperature and / or the current film-attached state, wherein n is a positive integer; controlling the ultrasonic sensor to emit n ultrasonic signals to the conductive medium and receive echo signals formed after each emitted ultrasonic signal is reflected; performing fingerprint detection according to the echo signals.

2. The method of claim 1, wherein determining the ultrasonic emission number n according to the current temperature comprises: determining the ultrasonic emission number n according to the current temperature and first mapping information, wherein the first mapping information indicates a mapping relationship between the temperature of the conductive medium and the ultrasonic emission number; determining the ultrasonic emission number n according to the current film-attached state comprises: determining the ultrasonic emission number n according to the current film-attached state and second mapping information, wherein the second mapping information indicates a mapping relationship between the film-attached state of the conductive medium and the ultrasonic emission number; determining the ultrasonic emission number n according to the current temperature and the current film-attached state comprises: determining the ultrasonic emission number n according to a current parameter combination and third mapping information, wherein the current parameter combination comprises the current temperature and the current film-attached state, and the third mapping information indicates a mapping relationship between the temperature, the film-attached state of the conductive medium and the ultrasonic emission number.

3. The method of claim 2, wherein, The method further comprises updating the first mapping information, and the updating of the first mapping information comprises: obtaining an updated temperature of the conductive medium, determining an ultrasonic emission number m corresponding to the updated temperature according to the updated temperature and the first mapping information, wherein m is a positive integer, controlling the ultrasonic sensor to emit m ultrasonic signals to the conductive medium and receive updated echo signals formed after each emitted ultrasonic signal is reflected, the temperature of the conductive medium when the ultrasonic sensor emits the m ultrasonic signals being the updated temperature, superimposing the m updated echo signals to obtain an updated cumulative sum signal, and updating the ultrasonic emission number m according to the intensity of the updated cumulative sum signal and a preset signal intensity interval.

4. The method of claim 3, wherein, The updating of the ultrasonic emission number m according to the intensity of the updated cumulative sum signal and the preset signal intensity interval comprises: if the intensity of the updated cumulative sum signal is within the signal intensity interval, the ultrasonic emission number m is updated to remain m; if the intensity of the updated cumulative sum signal is outside the signal intensity interval, an updated ultrasonic emission number corresponding to the updated temperature is determined according to the following formula: N 更新 = m * P 目标 / P 样本 N 更新 for indicating the number of ultrasound wave transmissions for the update, P 目标 for indicating the middle value of the signal strength interval, P 样本 for indicating the strength value of the update accumulated sum signal; the ultrasonic emission number m is updated to the updated ultrasonic emission number.

5. The method as claimed in claim 3, wherein, When the ultrasonic sensor emits the m ultrasonic signals, no finger is pressed on the pressing surface, and when the updated temperature of the conductive medium is obtained, no finger is pressed on the pressing surface. The ultrasonic sensor emits n times of ultrasonic signals to the conductive medium, and the pressing surface is pressed by a finger when the current temperature of the conductive medium is acquired.

6. The method according to any one of claims 3-5, characterized in that, The first mapping information comprises the temperature of the conductive medium, the number of ultrasonic signal emissions mapped with the temperature of the conductive medium, and the update state of the number of ultrasonic signal emissions. The determination of the number of ultrasonic signal emissions n according to the current temperature and the first mapping information comprises: The determination of the number of ultrasonic signal emissions mapped with the current temperature according to the current temperature and the first mapping information; If the update state of the number of ultrasonic signal emissions mapped with the current temperature is marked as updated, the number of ultrasonic signal emissions mapped with the current temperature is determined as the number of ultrasonic signal emissions n. If the update state of the number of ultrasonic signal emissions mapped with the current temperature is not marked as updated, the number of ultrasonic signal emissions n is determined according to the update state of the number of ultrasonic signal emissions mapped with at least one candidate temperature adjacent to the current temperature.

7. The method of claim 6, wherein, The determination of the number of ultrasonic signal emissions n according to the update state of the number of ultrasonic signal emissions mapped with at least one candidate temperature adjacent to the current temperature comprises: If there is a candidate temperature in the at least one candidate temperature whose mapped number of ultrasonic signal emissions is marked as updated, the number of ultrasonic signal emissions mapped with the candidate temperature whose update state is marked as updated and whose absolute value of difference from the current temperature is the smallest is determined as the number of ultrasonic signal emissions n. If there is no candidate temperature in the at least one candidate temperature whose mapped number of ultrasonic signal emissions is marked as updated, the number of ultrasonic signal emissions mapped with the current temperature is determined as the number of ultrasonic signal emissions n.

8. The method of claim 6, wherein, The determination of the number of ultrasonic signal emissions mapped with the current temperature according to the current temperature and the first mapping information comprises: The number of ultrasonic signal emissions mapped with the temperature closest to the current temperature in the first mapping information is determined as the number of ultrasonic signal emissions mapped with the current temperature.

9. The method according to any one of claims 2-5, characterized in that, The first mapping information comprises a mapping curve between the temperature of the conductive medium and the number of ultrasonic signal emissions. The determination of the number of ultrasonic signal emissions n according to the current temperature and the first mapping information comprises: The current temperature is mapped to the number of ultrasonic signal emissions n through the mapping curve.

10. The method of any one of claims 1-5, wherein, The determination of the number of ultrasonic signal emissions n according to the current temperature comprises: The number of ultrasonic signal emissions n is determined according to the current temperature and the number of high-voltage pulses output to the piezoelectric wafer when emitting ultrasonic signals.

11. The method according to any one of claims 1-5, characterized in that, The fingerprint detection according to the echo signals comprises: The n echo signals are superimposed to obtain a current cumulative sum signal, the fingerprint image data is analyzed according to the current cumulative sum signal, and the fingerprint detection is performed according to the fingerprint image data.

12. An ultrasonic fingerprint detection device, characterized by Comprise: The acquisition module is configured to acquire a current temperature and / or a current film pasting state of the conductive medium, wherein a first side of the conductive medium is attached to the ultrasonic sensor, and a second side of the conductive medium provides a pressing surface; The ultrasonic wave emission frequency determination module is configured to determine an ultrasonic wave emission frequency n according to the current temperature and / or the current film pasting state, wherein n is a positive integer; The signal acquisition module is configured to control the ultrasonic sensor to emit n times of ultrasonic wave signals to the conductive medium, and receive echo signals formed after each time of emitted ultrasonic wave signals is reflected; The fingerprint detection module is configured to perform fingerprint detection according to the echo signals.

13. The ultrasonic fingerprint detection apparatus according to claim 12, wherein The ultrasonic wave emission frequency determination module is configured to determine the ultrasonic wave emission frequency n according to the current temperature and first mapping information, wherein the first mapping information is used to indicate a mapping relationship between the temperature of the conductive medium and the ultrasonic wave emission frequency; or determine the ultrasonic wave emission frequency n according to the current film pasting state and second mapping information, wherein the second mapping information is used to indicate a mapping relationship between the film pasting state of the conductive medium and the ultrasonic wave emission frequency; or determine the ultrasonic wave emission frequency n according to a current parameter combination and third mapping information, wherein the current parameter combination includes the current temperature and the current film pasting state, and the third mapping information is used to indicate a mapping relationship between the temperature, the film pasting state and the ultrasonic wave emission frequency of the conductive medium.

14. The ultrasonic fingerprint detection apparatus according to claim 13, wherein The device further includes an updating module configured to update the first mapping information, and the updating of the first mapping information includes: acquiring an updated temperature of the conductive medium; determining an ultrasonic wave emission frequency m mapped with the updated temperature according to the updated temperature and the first mapping information, wherein m is a positive integer; controlling the ultrasonic sensor to emit m times of ultrasonic wave signals to the conductive medium, and receiving updated echo signals formed after each time of emitted ultrasonic wave signals is reflected, the temperature of the conductive medium when the ultrasonic sensor emits the m times of ultrasonic wave signals being the updated temperature; superimposing m updated echo signals to obtain an updated cumulative sum signal; and updating the ultrasonic wave emission frequency m according to the intensity of the updated cumulative sum signal and a preset signal intensity interval.

15. The ultrasonic fingerprint detection apparatus according to claim 14, wherein When the ultrasonic sensor emits the m times of ultrasonic wave signals, no finger is pressed on the pressing surface, and when the updated temperature of the conductive medium is acquired, no finger is pressed on the pressing surface; When the ultrasonic sensor emits n times of ultrasonic wave signals to the conductive medium, a finger is pressed on the pressing surface, and when the current temperature of the conductive medium is acquired, a finger is pressed on the pressing surface.

16. The ultrasonic fingerprint detection apparatus according to claim 14 or 15, characterized by, The first mapping information includes the temperature of the conductive medium, the ultrasonic wave emission frequency mapped with the temperature of the conductive medium, and the update state of the ultrasonic wave emission frequency; The ultrasonic wave emission frequency determination module is configured to determine the ultrasonic wave emission frequency mapped with the current temperature according to the current temperature and the first mapping information. If the update status of the number of ultrasonic emissions mapped to the current temperature is marked as updated, then the number of ultrasonic emissions mapped to the current temperature is determined as the number of ultrasonic emissions n. If the update status of the number of ultrasonic emissions mapped to the current temperature is not marked as updated, the number of ultrasonic emissions n is determined based on the update status of the number of ultrasonic emissions mapped to at least one candidate temperature adjacent to the current temperature.

17. The ultrasonic fingerprint detection apparatus according to claim 16, wherein The ultrasonic emission count determination module is further configured to: if there is a mapped ultrasonic emission count among the at least one candidate temperature that is marked as an updated candidate temperature, then determine the ultrasonic emission count mapped to the candidate temperature whose update status is marked as updated and whose absolute value of the difference with the current temperature is the smallest as the ultrasonic emission count n. If no corresponding number of ultrasonic emissions is mapped to any of the at least one candidate temperature and is marked as the updated candidate temperature, then the number of ultrasonic emissions mapped to the current temperature is determined as the number of ultrasonic emissions n.

18. The ultrasonic fingerprint detection apparatus according to any one of claims 12-15, wherein, The fingerprint detection module is used to superimpose the n echo signals to obtain the current accumulated sum signal, parse the fingerprint image data according to the current accumulated sum signal, and perform fingerprint detection according to the fingerprint image data.

19. An electronic device comprising: The processor, memory, communication interface, and communication bus are provided, wherein the processor, memory, and communication interface communicate with each other via the communication bus. The memory is used to store at least one executable instruction that causes the processor to perform the method as described in any one of claims 1-11.

20. A computer storage medium having a computer program stored thereon, which, when executed by a processor, implements the method as described in any one of claims 1-11.

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