Dynamic acquisition method and device of ultrasonic fingerprint data and electronic equipment

Abstract

The present specification provides a dynamic acquisition method and device of ultrasonic fingerprint data and electronic equipment, which can be used in the field of fingerprint identification technology. Based on the method, in specific implementation, the contact pressure information of the current finger relative to the fingerprint acquisition area and / or the surface characteristic information of the finger can be acquired first; the emission parameters of ultrasonic waves are adjusted according to the contact pressure information and / or the surface characteristic information of the finger; and the target fingerprint data is acquired based on the adjusted ultrasonic waves. Thus, the contact state of the finger can be determined and intelligently distinguished according to different situations, and the emission parameters of ultrasonic waves are adaptively and dynamically adjusted, and then the fingerprint data with fine surface characteristics and small errors can be acquired based on the adjusted ultrasonic waves, so that subsequent related fingerprint data processing such as fingerprint identification can be accurately realized based on the fingerprint data.

Description

Technical Field

[0001] This manual pertains to the field of fingerprint recognition technology, and particularly relates to methods, devices, and electronic equipment for the dynamic acquisition of ultrasonic fingerprint data. Background Technology

[0002] When a user's finger touches the fingerprint collection area to collect a fingerprint, the actual contact between the fingerprint collection area and the finger can vary greatly due to differences in finger pressing habits and finger surface conditions among different users. This affects the effective collection of fingerprint data and consequently the accuracy of subsequent fingerprint recognition.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This specification provides a method, apparatus, and electronic device for dynamic acquisition of ultrasonic fingerprint data. It can determine and adaptively adjust the emission parameters of ultrasonic waves according to the contact state of the finger, thereby acquiring fingerprint data with fine surface features and small errors based on the adjusted ultrasonic waves. This allows for accurate fingerprint data processing, such as fingerprint recognition, to be performed subsequently.

[0005] This specification provides a method for dynamic acquisition of ultrasonic fingerprint data, including:

[0006] Acquire the contact pressure information of the finger relative to the fingerprint acquisition area and / or the surface characteristic information of the finger;

[0007] The ultrasonic emission parameters are adjusted based on the contact pressure information and / or the surface characteristics of the finger.

[0008] Target fingerprint data is acquired based on the adjusted ultrasound.

[0009] In one embodiment, the ultrasound wave includes a focused wave and / or a plane wave;

[0010] Accordingly, the emission parameters of the ultrasonic wave include: frequency and / or phase.

[0011] In one embodiment, the surface characteristic information includes at least one of the following: roughness, smoothness, and humidity.

[0012] In one embodiment, adjusting the ultrasonic wave emission parameters based on the contact pressure information and / or the surface characteristics of the finger includes:

[0013] When the contact pressure indicated by the contact pressure information is greater than a preset first pressure threshold, the frequency of the ultrasonic wave is reduced according to the first adjustment rule.

[0014] When the contact pressure indicated by the contact pressure information is less than a preset second pressure threshold, the frequency of the ultrasonic wave is increased according to the first adjustment rule; wherein the preset first pressure threshold is greater than the preset second pressure threshold.

[0015] In one embodiment, adjusting the ultrasonic wave emission parameters based on the contact pressure information and / or the surface characteristics of the finger includes:

[0016] When the surface characteristic information indicates that the roughness of the finger is greater than a preset first roughness threshold, the phase of the ultrasonic wave is increased according to the second adjustment rule.

[0017] When the surface characteristic information indicates that the roughness of the finger is less than a preset second roughness threshold, the phase of the ultrasonic wave is reduced according to the second adjustment rule; wherein the preset first roughness threshold is greater than the preset second roughness threshold.

[0018] In one embodiment, adjusting the ultrasonic wave emission parameters based on the contact pressure information and / or the surface characteristics of the finger includes:

[0019] When the humidity of the finger indicated by the surface characteristic information is greater than a preset first humidity threshold, the frequency of the ultrasonic wave is reduced according to the third adjustment rule.

[0020] When the humidity of the finger indicated by the surface characteristic information is less than a preset second humidity threshold, the frequency of the ultrasonic wave is increased according to a third adjustment rule; wherein the preset first humidity threshold is greater than the preset second humidity threshold.

[0021] In one embodiment, the method further includes:

[0022] Determine the matching target angle scanning range;

[0023] Based on the target angle scanning range, the ultrasonic transducer is controlled to perform multi-angle scanning to obtain multiple first-type echo signals at different angles.

[0024] Target fingerprint data is obtained based on multiple Type I echo signals.

[0025] In one embodiment, acquiring target fingerprint data based on multiple first-type echo signals includes:

[0026] Based on multiple Type I echo signals, the depth information of the finger surface at multiple angles is determined by calculating the signal propagation time.

[0027] Based on multiple Type I echo signals, corresponding signal parameters are extracted; wherein, the signal parameters include at least one of the following: intensity, phase, and time delay;

[0028] By utilizing depth information from multiple angles and corresponding signal parameters, target fingerprint data is obtained through data fusion.

[0029] In one embodiment, depth information from multiple angles and corresponding signal parameters are used to obtain target fingerprint data through data fusion, including:

[0030] Alignment and calibration processes are performed on depth information from multiple angles to obtain multiple processed depth information;

[0031] Based on the signal parameters, a three-dimensional fingerprint image is constructed by combining multiple processed depth information, which serves as the target fingerprint data.

[0032] In one embodiment, the method further includes:

[0033] Determine the matching target frequency range and target phase range;

[0034] Based on the target frequency range and the target phase range, the ultrasonic transducer is controlled to perform multi-frequency and multi-phase scanning to obtain multiple second-type echo signals.

[0035] Target fingerprint data is obtained based on multiple Type II echo signals.

[0036] This specification also provides a device for dynamic acquisition of ultrasonic fingerprint data, including:

[0037] The acquisition module is used to acquire the contact pressure information of the current finger relative to the fingerprint acquisition area and / or the surface characteristic information of the finger;

[0038] An adjustment module is used to adjust the ultrasonic wave emission parameters based on the contact pressure information and / or the surface characteristics of the finger.

[0039] The acquisition module is used to acquire target fingerprint data based on the adjusted ultrasonic waves.

[0040] This specification also provides an electronic device, including a processor and a memory for storing processor-executable instructions, wherein the processor executes the instructions to implement the steps of the dynamic acquisition method for ultrasonic fingerprint data.

[0041] This specification also provides a computer-readable storage medium storing computer instructions that, when executed by a processor, implement the steps of the dynamic acquisition method for ultrasonic fingerprint data.

[0042] Based on the ultrasonic fingerprint data dynamic acquisition method, device, and electronic equipment provided in this specification, the contact pressure information of the finger relative to the fingerprint acquisition area and / or the surface characteristic information of the finger can be acquired first; then, based on the contact pressure information and / or the surface characteristic information of the finger, the ultrasonic emission parameters can be adjusted in a targeted manner; and target fingerprint data can be acquired based on the adjusted ultrasonic waves. This allows for the determination and intelligent differentiation of different situations according to the finger's contact state, adaptively and dynamically adjusting the ultrasonic emission parameters, thereby enabling the acquisition of fingerprint data with fine surface features and small errors based on the adjusted ultrasonic waves. This allows for subsequent accurate fingerprint data processing, such as fingerprint recognition, based on this fingerprint data. Attached Figure Description

[0043] To more clearly illustrate the embodiments of this specification, the accompanying drawings used in the embodiments will be briefly introduced below. The drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a flowchart illustrating a method for dynamically acquiring ultrasonic fingerprint data according to an embodiment of this specification.

[0045] Figure 2 This is a schematic diagram of an embodiment of the dynamic acquisition method for ultrasonic fingerprint data provided in the embodiments of this specification, applied in a scenario example;

[0046] Figure 3 This is a schematic diagram of an embodiment of the dynamic acquisition method for ultrasonic fingerprint data provided in the embodiments of this specification, applied in a scenario example.

[0047] Figure 4 This is a schematic diagram of an embodiment of the dynamic acquisition method for ultrasonic fingerprint data provided in the embodiments of this specification, applied in a scenario example;

[0048] Figure 5 This is a schematic diagram of an embodiment of the dynamic acquisition method for ultrasonic fingerprint data provided in the embodiments of this specification, applied in a scenario example;

[0049] Figure 6 This is a schematic diagram of the structural composition of an electronic device provided in one embodiment of this specification;

[0050] Figure 7 This is a schematic diagram of the structure of a dynamic acquisition device for ultrasonic fingerprint data provided in one embodiment of this specification. Detailed Implementation

[0051] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0052] It should be noted that the information and data related to users involved in the embodiments of this specification are all information and data authorized by the user or fully authorized by the relevant parties. Furthermore, the collection, storage, use, processing, transmission, provision, disclosure, and application of the relevant data all comply with relevant laws, regulations, and standards, and necessary confidentiality measures have been taken. They do not violate public order and good morals, and corresponding operation entry points are provided for users or relevant parties to choose to authorize or refuse.

[0053] It should also be noted that in the embodiments of this specification, certain software, components, models and other existing solutions in the industry may be mentioned. These should be regarded as exemplary and are only intended to illustrate the feasibility of implementing the technical solution of this application. However, it does not mean that the applicant has used or necessarily used the solution.

[0054] See Figure 1 As shown in the embodiments of this specification, a method for dynamically acquiring ultrasonic fingerprint data is provided. Specifically, this method may include the following:

[0055] S101: Obtain the contact pressure information of the current finger relative to the fingerprint acquisition area and / or the surface characteristic information of the finger;

[0056] S102: Adjust the ultrasonic wave emission parameters based on the contact pressure information and / or the surface characteristics of the finger;

[0057] S103: Acquire target fingerprint data based on the adjusted ultrasonic waves.

[0058] The aforementioned method for dynamically acquiring ultrasonic fingerprint data can be applied to fingerprint recognition devices (or other fingerprint processing devices such as fingerprint acquisition devices). Specifically, the fingerprint recognition device can be applied to access control systems, smart devices (e.g., smartphones), or other systems such as identity information collection systems.

[0059] The following description uses a fingerprint recognition device as an example. For other fingerprint processing devices, please refer to the relevant embodiments of the fingerprint recognition device; these will not be elaborated upon in this specification.

[0060] The aforementioned fingerprint recognition device includes at least a fingerprint acquisition area. For example, this fingerprint acquisition area can be a press-screen. When performing fingerprint recognition, the user can place their finger on the fingerprint acquisition area to acquire the required fingerprint data. In some cases, the user can also place their palm on the fingerprint acquisition area to acquire corresponding palmprint data.

[0061] Furthermore, multiple ultrasonic transducers can be installed below the fingerprint acquisition area. Specifically, these ultrasonic transducers (or ultrasonic wave transducers) can be understood as devices that can convert electromagnetic energy into mechanical energy (sound energy).

[0062] Specifically, the aforementioned ultrasonic transducer includes at least the following structures: piezoelectric element, electrode, matching layer, backing layer, etc.

[0063] The piezoelectric elements mentioned above are typically made of materials exhibiting the piezoelectric effect, such as piezoelectric ceramics, lithium niobate, barium titanate, lead zirconate titanate, aluminum nitride, polyvinylidene fluoride (PVDF), or polyvinylidene fluoride-trifluoroethylene copolymer (PVDF-TrFE), etc. When a voltage is applied, the piezoelectric material deforms, generating an ultrasonic signal. Similarly, when an ultrasonic signal is received, the piezoelectric material generates a corresponding electrical signal. Therefore, ultrasonic transducers can utilize piezoelectric elements to transmit and receive ultrasonic signals.

[0064] The electrodes described above are attached to both sides of the piezoelectric element to apply voltage or receive electrical signals generated by the piezoelectric element. The electrodes are typically made of metal (e.g., silver or platinum) to provide stable electrical conductivity and to bond well with the piezoelectric material.

[0065] The matching layer described above is used to adjust the acoustic impedance difference between the piezoelectric element and the object being measured (e.g., the skin of a finger or air). The matching layer can be a single layer or multiple layers of material, which can improve the signal transmission efficiency of the ultrasonic transducer while reducing the reflection loss of the ultrasonic signal.

[0066] The aforementioned backing layer is placed on the back of the piezoelectric element and is usually made of damping material. It can absorb the back propagation of ultrasonic signals and is mainly used to reduce unnecessary echoes, prevent reflection interference, and enhance the forward propagation of ultrasonic signals.

[0067] Specifically, the aforementioned ultrasonic transducer is also connected to corresponding transmitting and receiving circuits. Accordingly, in practical implementation, the transmitting circuit can control the ultrasonic transducer to emit different ultrasonic signals. The receiving circuit receives the echo signals based on the emitted ultrasonic signals; and based on the echo signals, through appropriate signal processing, the required fingerprint data containing the user's fingerprint feature information is obtained.

[0068] Specifically, the aforementioned ultrasonic transducer can support multiple different ultrasonic modes. Correspondingly, the aforementioned fingerprint recognition device can obtain fingerprint data by emitting corresponding ultrasonic signals based on different ultrasonic modes.

[0069] The aforementioned ultrasonic modes include: focused wave mode and / or plane wave mode.

[0070] Specifically, based on the plane wave mode, multiple ultrasonic transducers on the entire surface can be driven simultaneously to emit ultrasonic signals of the same phase and frequency to form a plane wave that is transmitted to the surface of the finger (or other objects being detected, such as the palm), thereby enabling rapid detection and acquisition of fingerprint feature information over a large area.

[0071] Based on the focused wave mode, the phase and frequency of ultrasonic signals emitted by multiple designated ultrasonic transducers can be activated and adjusted, so that ultrasonic waves can form focused waves in a specific area, thereby enabling the detection and acquisition of fingerprint feature information in a small area with high precision.

[0072] Among them, the plane wave mode has the advantages of low power consumption, high frame rate, fast system response speed and large coverage area compared with the focused wave mode, but it has limited penetration and low accuracy.

[0073] Compared to the plane wave mode, the above-mentioned focused wave mode has the advantages of high precision and long penetration distance, but it also has the advantages of high power consumption, low frame rate and long system response time.

[0074] Pressure sensors and / or surface characteristic sensors may also be installed below the fingerprint acquisition area.

[0075] The pressure sensor described above can be used to detect the amount of pressure applied by the user when pressing the fingerprint collection area. The surface characteristic sensor described above can be used to detect the skin surface characteristics (e.g., humidity, roughness, smoothness, etc.) of the object being detected (e.g., a finger) that the user is pressing on the fingerprint collection area.

[0076] In addition, an adaptive control unit (e.g., a microcontroller chip) is also installed below the fingerprint acquisition area. The adaptive control unit can be electrically connected to the sensor device, transmitting circuit, etc.

[0077] The aforementioned target fingerprint data can be specifically understood as data containing the user's fingerprint characteristics that can be used for subsequent data processing such as fingerprint recognition. For example, echo signals containing the user's fingerprint features, or feature data obtained after further processing based on the aforementioned echo signals.

[0078] Based on the aforementioned fingerprint recognition device, when a user presses the fingerprint acquisition area, sensor devices such as pressure sensors and surface characteristic sensors can first collect data signals that reflect the user's pressing contact, such as contact pressure information and / or finger surface characteristic information; and send the aforementioned data signals to the adaptive control unit; the adaptive control unit can determine the current contact pressure information and / or finger surface characteristic information based on the aforementioned data signals, distinguish different contact situations; and adaptively and dynamically adjust the emission parameters of the ultrasonic transducer when emitting ultrasonic waves through the transmitting circuit; thus, based on the adjusted ultrasonic waves, it can better adapt to the current contact situation and acquire target fingerprint data with high accuracy and good effect.

[0079] In some embodiments, the aforementioned ultrasonic waves may specifically include focused waves; correspondingly, the adjustable ultrasonic wave emission parameters may specifically include frequency and / or phase, etc. For focused waves, the phase may differ between different ultrasonic transducers.

[0080] The aforementioned ultrasonic waves may also include plane waves; correspondingly, the adjustable ultrasonic wave transmission parameters may include frequency and / or phase, etc. For plane waves, different ultrasonic transducers have the same phase.

[0081] In specific implementation, adjusting the ultrasonic emission parameters based on the contact pressure information and / or the surface characteristics of the finger may include: determining the type of ultrasonic currently being used; determining the adjustable ultrasonic emission parameters based on the type of ultrasonic currently being used; and then determining the ultrasonic emission parameters based on the contact pressure information and / or the surface characteristics of the finger.

[0082] For example, when it is determined that the type of ultrasound currently being used is a focused wave, the frequency and / or phase of the ultrasound are adjusted based on the contact pressure information and / or the surface characteristics of the finger. As another example, when it is determined that the type of ultrasound currently being used is a plane wave, the frequency of the ultrasound is adjusted based on the contact pressure information and / or the surface characteristics of the finger. The specific methods for adjusting the frequency and phase of the ultrasound will be explained in detail later.

[0083] It should be noted that the types of ultrasound and their emission parameters listed above are only illustrative. In actual implementation, other types of ultrasound, as well as emission parameters (e.g., emission intensity, emission angle, etc.) matching other types of ultrasound, may be included depending on the specific circumstances and processing requirements.

[0084] For example, the penetrability of ultrasound waves can be adjusted by changing their frequency. For instance, when the frequency of an ultrasound wave is higher, its penetrating power is relatively stronger; conversely, when the frequency is lower, its penetrating power is relatively weaker.

[0085] Adjusting the phase of the ultrasonic wave can regulate the phase compensation angle of the reflected ultrasonic signal, thereby adjusting the offset of the reflected signal and preventing the acquired image from becoming blurry due to signal offset.

[0086] Specifically, for example, for focused waves, the frequency adjustment range can be greater than or equal to 5MHz and less than or equal to 20MHz; the phase adjustment range can be greater than or equal to 0 degrees and less than 360 degrees.

[0087] In some embodiments, during specific implementation, the system can first detect whether the user is currently pressing the fingerprint acquisition area based on a plane wave mode. When it is determined that the user is currently pressing the fingerprint acquisition area, the system can collect the contact pressure information of the finger relative to the fingerprint acquisition area and / or the surface characteristic information of the finger through a corresponding sensor device. Then, the system can switch from the plane wave mode to the focused wave mode. Based on the contact pressure information and / or the surface characteristic information of the finger, the system can adjust the emission parameters of the focused wave. Finally, based on the adjusted focused wave, the system can collect the target fingerprint data.

[0088] In practice, the user's pressing position can be determined based on the detection results of the plane wave; then, the emission angle can be adjusted to align with the user's pressing position; and finally, the target fingerprint data can be collected based on the adjusted focused wave.

[0089] In this way, plane wave detection with low power consumption and high speed can be used first to determine whether a user has pressed the fingerprint collection area; after confirming that a user has pressed the fingerprint collection area, the adjusted focused wave with higher power consumption but higher accuracy, and which matches the current contact pressure information and / or the surface characteristics of the finger, can be used to collect the required fingerprint data. This way, both power consumption and accuracy can be taken into account, and high-quality target fingerprint data can be collected.

[0090] In some embodiments, the surface characteristic information described above may specifically include at least one of the following: roughness, smoothness, humidity, etc.

[0091] Roughness, smoothness, and humidity all affect the reflected signal of ultrasound waves. Generally, when the skin of the object being tested has high roughness, low smoothness, and high humidity (e.g., sweat on the fingers), the reflected signal of ultrasound waves is more likely to produce phase deviation, thus affecting the data quality of the collected fingerprint data.

[0092] In some embodiments, before implementation, an ultrasonic-based sample fingerprint recognition device can be used to conduct numerous experimental tests by adjusting relevant variables such as contact pressure, roughness, smoothness, and humidity, resulting in a large number of experimental test records. Based on these records, cluster learning is used to analyze the influence mechanism and effect of these variables on fingerprint data acquisition by the sample fingerprint recognition device. Then, based on the influence mechanism and effect, the ultrasonic emission parameters corresponding to each variable are determined. Next, multiple sub-sample data groups corresponding to each variable are selected from the experimental test records; each sub-sample data group corresponds to one variable. Finally, based on each sub-sample... This dataset, combining the influence mechanism and effect of the variable factors corresponding to the subsample dataset, fits the interaction relationship between the variable factors and the corresponding ultrasonic emission parameters. Based on this interaction relationship, multiple preset adjustment rules are constructed for each variable factor. Each preset adjustment rule corresponds to at least one variable factor and includes one or more reference value ranges for that variable factor, as well as emission parameter adjustment suggestions corresponding to each reference value range (including: the parameter type of the emission parameter to be adjusted, the adjustment method of the emission parameter, the adjustment range of the emission parameter, etc.). Finally, multiple preset adjustment rules are combined to establish a corresponding preset adjustment rule set.

[0093] In specific implementation, adjusting the ultrasonic emission parameters based on the contact pressure information and / or the surface characteristic information of the finger may include: querying a preset adjustment rule set based on the contact pressure information to determine a preset adjustment rule corresponding to the contact pressure, as a first adjustment rule; then querying the first adjustment rule based on the contact pressure information to determine an emission parameter adjustment suggestion corresponding to the reference value range to which the contact pressure information belongs, as a first adjustment suggestion; and / or, querying a preset adjustment rule set based on the surface characteristic information of the finger (e.g., roughness) to determine a preset adjustment rule corresponding to the finger surface characteristic, as a second adjustment rule (and / or a third adjustment rule corresponding to humidity); and querying the second adjustment rule based on the finger surface characteristic information to determine an emission parameter adjustment suggestion corresponding to the reference value range to which the finger surface characteristic information belongs, as a second adjustment suggestion. Then, based on the first adjustment suggestion and / or the second adjustment suggestion, a target adjustment suggestion is determined; and based on the target adjustment suggestion, the ultrasonic emission parameters are adjusted.

[0094] In some embodiments, see Figure 2 As shown, adjusting the ultrasonic wave emission parameters based on the contact pressure information and / or the surface characteristics of the finger can, in specific implementation, include the following:

[0095] S1: When the contact pressure indicated by the contact pressure information is greater than the preset first pressure threshold, the frequency of the ultrasonic wave is reduced according to the first adjustment rule;

[0096] S2: When the contact pressure indicated by the contact pressure information is less than the preset second pressure threshold, the frequency of the ultrasonic wave is increased according to the first adjustment rule; wherein the preset first pressure threshold is greater than the preset second pressure threshold.

[0097] Specifically, when the contact pressure between the object being detected (e.g., a finger) and the fingerprint collection area is too low when the user presses the fingerprint collection area, insufficient contact can easily occur, resulting in insufficient signal. In this case, the transmission frequency of the ultrasonic waves can be reduced to weaken the projection and reflection of the ultrasonic waves, so that sufficient signals can be collected to generate high-quality fingerprint data.

[0098] Conversely, if the contact pressure between the fingerprint sensor and the fingerprint collection area is too high when the user presses the fingerprint sensor, the signal may be distorted due to excessive pressure. In this case, the ultrasonic wave emission frequency can be increased to ensure that the ultrasonic wave has sufficient penetrating power in order to collect high-quality fingerprint data.

[0099] The aforementioned preset first pressure threshold and preset second pressure threshold can be determined based on a large number of experimental test records. For example, the preset first pressure threshold can be 0.8N, and the preset second pressure threshold can be 0.2N.

[0100] In practice, when the contact pressure indicated by the contact pressure information is greater than the preset first pressure threshold, it can be determined that the current state is under high pressure. At this time, the frequency of the ultrasonic wave can be reduced in a targeted manner according to the first adjustment rule. For example, the transmission frequency of the ultrasonic wave can be reduced from the original 8MHz to 5MHz in order to collect high-quality fingerprint data.

[0101] When the contact pressure indicated by the contact pressure information is less than the preset second pressure threshold, it can be determined that the current state is low pressure. At this time, the frequency of the ultrasonic wave can be increased in a targeted manner according to the first adjustment rule. For example, the ultrasonic wave emission frequency can be increased from the original 5MHz to 8MHz or even higher in order to collect high-quality fingerprint data.

[0102] When the contact pressure indicated by the contact pressure information is less than or equal to the preset first pressure threshold and greater than or equal to the preset second pressure threshold, it can be determined that the current pressure is in a suitable state. At this time, the frequency of the ultrasonic wave does not need to be adjusted, and the current frequency of the ultrasonic wave can continue to be used.

[0103] Based on the above embodiments, the ultrasonic emission parameters can be precisely and accurately adaptively adjusted by distinguishing different pressure states according to the contact pressure information.

[0104] In some embodiments, see Figure 3 As shown, adjusting the ultrasonic wave emission parameters based on the contact pressure information and / or the surface characteristics of the finger can, in specific implementation, include the following:

[0105] S1: When the surface characteristic information indicates that the roughness of the finger is greater than a preset first roughness threshold, the phase of the ultrasonic wave is increased according to the second adjustment rule.

[0106] S2: When the surface characteristic information indicates that the roughness of the finger is less than a preset second roughness threshold, the phase of the ultrasonic wave is reduced according to the second adjustment rule; wherein, the preset first roughness threshold is greater than the preset second roughness threshold.

[0107] Specifically, when a user presses the fingerprint sensor area, if the surface of the object being detected is rough or uneven, the reflected signal is prone to phase deviation or signal offset, which can cause interference and affect the quality of the collected fingerprint data. Furthermore, extensive experimental testing has revealed that different levels of roughness have different effects; both excessively rough and excessively smooth surfaces can negatively impact the quality of the collected fingerprint data.

[0108] The aforementioned preset first roughness threshold and preset second roughness threshold can be determined based on a large number of experimental test records. Specifically, for example, the preset first roughness threshold can be 1.5, and the preset second roughness threshold can be 0.5.

[0109] In practice, when the surface characteristic information indicates that the roughness of the finger is greater than the preset first roughness threshold, it can be determined that the current state is high roughness (too rough). At this time, the phase of the ultrasonic wave can be increased in a targeted manner according to the second adjustment rule. For example, the emission phase of the ultrasonic wave can be increased from the original 0 degrees to 45 degrees to increase phase compensation, so as to avoid signal offset causing image blurring, thereby acquiring high-quality fingerprint data.

[0110] When the surface characteristic information indicates that the roughness of the finger is less than the preset second roughness threshold, it can be determined that the current roughness is low (too smooth). At this time, the phase of the ultrasonic wave can be reduced in a targeted manner according to the second adjustment rule. For example, the emission phase of the ultrasonic wave can be reduced from the original 30 degrees to 10 degrees to reduce phase compensation, so as to maintain the accuracy and consistency of the signal and thus collect high-quality fingerprint data.

[0111] When the surface characteristic information indicates that the roughness of the finger is greater than or equal to the preset second roughness threshold and less than or equal to the preset first roughness threshold, it can be determined that the current roughness state is normal. In this case, the phase does not need to be adjusted.

[0112] Based on the above embodiments, the ultrasonic emission parameters can be precisely and accurately adaptively adjusted by distinguishing different roughness states according to surface characteristic information.

[0113] For examples of smoothness, please refer to the above examples of roughness; these will not be repeated in this specification.

[0114] In some embodiments, adjusting the ultrasonic wave emission parameters based on the contact pressure information and / or the surface characteristics of the finger may include the following:

[0115] S1: When the humidity of the finger indicated by the surface characteristic information is greater than the preset first humidity threshold, the frequency of the ultrasonic wave is reduced according to the third adjustment rule.

[0116] S2: When the humidity of the finger indicated by the surface characteristic information is less than the preset second humidity threshold, the frequency of the ultrasonic wave is increased according to the third adjustment rule; wherein the preset first humidity threshold is greater than the preset second humidity threshold.

[0117] Specifically, when a user presses the fingerprint collection area, the humidity of the object being detected will affect the moisture on the surface of the object's skin, and the moisture will affect the transmission and reflection of the ultrasonic signal.

[0118] The aforementioned preset first humidity threshold and preset second humidity threshold can be determined based on a large number of experimental test records.

[0119] In practice, when the humidity indicated by the surface characteristic information is greater than the preset first humidity threshold, it can be determined that the skin is currently in a humid state (excessive moisture on the skin surface). At this time, according to the third adjustment rule corresponding to humidity, the frequency of the ultrasonic waves can be reduced in a targeted manner to weaken the transmissibility of the signal, thereby enabling the collection of high-quality fingerprint data.

[0120] When the surface characteristic information indicates that the finger's humidity is less than the preset second roughness threshold, it can be determined that the finger is currently in a dry state (too little moisture on the skin surface). At this time, according to the third adjustment rule, the frequency of the ultrasound can be increased in a targeted manner to enhance the signal transmittance, thereby enabling the acquisition of high-quality fingerprint data.

[0121] When the humidity of the finger indicated by the surface characteristic information is greater than or equal to the preset second humidity threshold and less than or equal to the preset first humidity threshold, it can be determined that the current humidity is in a normal state. In this case, the frequency does not need to be adjusted.

[0122] Based on the above embodiments, the ultrasonic emission parameters can be precisely and accurately adaptively adjusted by distinguishing different humidity states according to surface characteristic information.

[0123] In some embodiments, during the process of acquiring target fingerprint data based on the adjusted ultrasonic waves, the emission intensity of the ultrasonic transducer can be received and dynamically adjusted according to the corresponding echo signal so that the adjusted ultrasonic waves can be focused on the area of ​​interest as much as possible, thereby obtaining target fingerprint data with relatively better results.

[0124] In some embodiments, the above-mentioned acquisition of target fingerprint data based on adjusted ultrasonic waves may specifically include: emitting adjusted ultrasonic waves according to the emission parameters of the adjusted ultrasonic waves; receiving corresponding echo signals; and obtaining the required target fingerprint data containing the user's fingerprint feature information through corresponding signal processing based on the echo signals.

[0125] Specifically, after receiving the echo signal, it can be preprocessed. This preprocessing may include signal filtering and / or noise suppression. This yields a recognizable preprocessed echo signal, which in turn allows for the generation of target fingerprint data with higher accuracy and lower error.

[0126] In some embodiments, when specifically collecting target fingerprint data, depending on different situations or scenarios, target fingerprint data may be collected based on only one type of ultrasonic wave; alternatively, target fingerprint data may be collected simultaneously based on multiple different ultrasonic waves. These multiple different ultrasonic waves may include one or more combinations of the following: ultrasonic waves with multiple different emission angles, ultrasonic waves with multiple different frequencies, and ultrasonic waves with multiple different phases.

[0127] Specifically, for example, the security level of the current application scenario can be detected first. If the security level is greater than a preset security level threshold, the application scenario is considered to have high precision requirements and needs to use multiple different ultrasonic sensors simultaneously (e.g., bank identity verification). Therefore, it can be determined that multiple different ultrasonic sensors should be used simultaneously to acquire the target fingerprint data. Conversely, if the security level is less than or equal to the preset security level threshold, the application scenario is considered to have low precision requirements and only needs rapid detection. Therefore, it can be determined that only one type of ultrasonic sensor should be used to acquire the target fingerprint data.

[0128] For example, target fingerprint data can be acquired first by identifying and using a matching ultrasonic wave; then, the quality of the target fingerprint data can be checked to see if it meets the preset quality requirements; if it is determined that the quality of the target fingerprint data does not meet the preset quality requirements, it can be determined that multiple different ultrasonic waves should be used simultaneously to reacquire the target fingerprint data.

[0129] In some embodiments, see Figure 4 As shown, in specific implementations, the method may also include the following:

[0130] S1: Determine the matching target angle scanning range;

[0131] S2: Based on the target angle scanning range, control the ultrasonic transducer to perform multi-angle scanning to obtain multiple first-type echo signals at different angles;

[0132] S3: Obtain target fingerprint data based on multiple Type I echo signals.

[0133] Specifically, when it is determined that multiple different ultrasonic waves need to be used simultaneously to acquire target fingerprint data, the required target fingerprint data can be acquired based on ultrasonic waves from multiple different angles.

[0134] First, a matching target angle scanning range can be determined based on the size of the object being detected (e.g., a finger) that the user is pressing on the fingerprint collection area. For example, this range can be greater than or equal to 0 degrees and less than or equal to 90 degrees. This target angle scanning range can cover the key areas of the object being detected.

[0135] Then, based on the target angle scanning range and a preset step size (e.g., 30 degrees), the ultrasonic transducer can be controlled to perform multi-angle scanning, obtaining multiple Type I echo signals at different angles. For example, Type I echo signals based on 30-degree ultrasound, 60-degree ultrasound, and 90-degree ultrasound. This allows for the acquisition of multiple Type I echo signals for the same object based on ultrasound waves at different angles. Each Type I echo signal corresponds to one angle.

[0136] Furthermore, multiple Type I echo signals can be used in combination to construct target fingerprint data that can effectively reduce environmental noise and interference, has high reliability and accuracy, and is applicable to a variety of complex environmental conditions.

[0137] In some embodiments, the acquisition of target fingerprint data based on multiple first-type echo signals may, in specific implementation, include the following:

[0138] S1: Based on multiple Type I echo signals, the depth information of the finger surface at multiple angles is determined by calculating the signal propagation time;

[0139] S2: Extract the corresponding signal parameters based on multiple Type I echo signals; wherein the signal parameters include at least one of the following: intensity, phase, and time delay;

[0140] S3: Target fingerprint data is obtained by using depth information from multiple angles and corresponding signal parameters through data fusion.

[0141] In practice, the depth information of the target object from multiple angles and the corresponding signal parameters can be extracted from multiple first-type echo signals in the manner described above. Then, based on the corresponding algorithm, a high-resolution two-dimensional fingerprint image can be generated by comprehensively utilizing the aforementioned depth information and signal parameters, which can be used as the target fingerprint data. Alternatively, a three-dimensional fingerprint image with strong anti-interference properties can be constructed by fusing the aforementioned depth information and signal parameter data, which can also be used as the target fingerprint data.

[0142] In some embodiments, the target fingerprint data is obtained by data fusion using depth information from multiple angles and corresponding signal parameters. In specific implementations, this may include the following:

[0143] S1: Alignment and calibration are performed on depth information from multiple angles to obtain multiple processed depth information;

[0144] S2: Based on the signal parameters, multiple processed depth information are combined to construct a three-dimensional fingerprint image, which serves as the target fingerprint data.

[0145] In practice, by aligning and calibrating the depth information from multiple angles, errors caused by different scanning angles can be eliminated, so that the processed depth information can be used to construct target fingerprint data with relatively smaller errors.

[0146] In practice, based on the corresponding 3D modeling algorithm, multiple processed depth information can be combined according to the signal parameters to perform 3D reconstruction and obtain the corresponding 3D fingerprint image as the target fingerprint data.

[0147] This approach effectively utilizes depth information from different angles to optimize and enhance fingerprint images, removing noise and errors, and improving image clarity and detail. Consequently, it effectively reduces environmental noise and interference, enhances image reliability and robustness, and yields target fingerprint data that is suitable for various complex environmental conditions and possesses strong anti-interference capabilities.

[0148] Correspondingly, when a user registers their fingerprint, they can also collect multiple Type I echo signals by scanning from multiple angles in the same way as described above, and then combine these multiple Type I echo signals to construct a user fingerprint feature template that is relatively better for that user.

[0149] In some embodiments, see Figure 5 As shown, in specific implementations, the method may also include the following:

[0150] S1: Determine the matching target frequency range and target phase range;

[0151] S2: Based on the target frequency range and target phase range, control the ultrasonic transducer to perform multi-frequency and multi-phase scanning to obtain multiple second-type echo signals;

[0152] S3: Obtain target fingerprint data based on multiple second-type echo signals.

[0153] Specifically, when it is determined that multiple different ultrasonic waves need to be used simultaneously to acquire target fingerprint data, the required target fingerprint data can be acquired based on multiple ultrasonic waves of different frequencies and ranges.

[0154] In practice, the target frequency range and target phase range can be determined based on the contact pressure information and / or the surface characteristics of the finger.

[0155] In practical implementation, the ultrasonic transducer can be controlled to perform multi-frequency, multi-phase scanning based on the target frequency and phase range, obtaining multiple Type II echo signals based on different frequencies and phases. Each Type II echo signal corresponds to a frequency and / or a phase. This results in a relatively rich and comprehensive set of Type II echo signals covering multiple frequencies and phases. Furthermore, by fusing these multiple Type II echo signals, target fingerprint data containing a wealth of detailed information can be constructed. Based on this target fingerprint data, high-precision fingerprint detection and recognition under complex environmental conditions can be achieved.

[0156] Correspondingly, when a user registers their fingerprint, they can also collect multiple second-type echo signals through multi-frequency multi-phase scanning in the manner described above, and then combine these multiple second-type echo signals to construct a user fingerprint feature template that is relatively better for that user.

[0157] In some embodiments, after collecting the target fingerprint data, the method may further include the following: generating a corresponding target fingerprint image based on the target fingerprint data; comparing the fingerprint features of the target fingerprint image with a preset user fingerprint feature template to obtain a target comparison result; and determining whether the fingerprint recognition passes based on the target comparison result.

[0158] In practice, corresponding image processing algorithms can be used to generate a target fingerprint image containing the user's fingerprint feature information based on the target fingerprint data. Then, the target fingerprint image is used to compare the fingerprint features with the preset user fingerprint feature template stored during the fingerprint enrollment stage to obtain the corresponding target comparison result.

[0159] Based on the comparison results, if the similarity of the fingerprint features between the two fingerprints is greater than or equal to a preset similarity threshold, the fingerprint recognition is considered successful. Otherwise, the fingerprint recognition is considered unsuccessful.

[0160] As can be seen from the above, the dynamic acquisition method for ultrasonic fingerprint data provided in the embodiments of this specification, in specific implementation, can first acquire the contact pressure information of the finger relative to the fingerprint acquisition area and / or the surface characteristic information of the finger; adjust the emission parameters of the ultrasonic waves according to the contact pressure information and / or the surface characteristic information of the finger; and acquire target fingerprint data based on the adjusted ultrasonic waves. This allows for the determination and adaptive dynamic adjustment of the ultrasonic wave emission parameters according to the contact state of the finger, thereby enabling the acquisition of fingerprint data with fine surface features and small errors based on the adjusted ultrasonic waves. This allows for subsequent accurate fingerprint data processing, such as fingerprint recognition, based on this fingerprint data.

[0161] This specification provides an electronic device through its embodiments. (See attached document.) Figure 6 As shown. The electronic device includes a network communication port 601, a processor 602, and a memory 603. These structures are connected by internal cables so that they can perform specific data interaction.

[0162] Specifically, the network communication port 601 can be used to acquire the contact pressure information of the finger relative to the fingerprint acquisition area and / or the surface characteristic information of the finger.

[0163] The processor 602 can be used to adjust the emission parameters of ultrasonic waves based on the contact pressure information and / or the surface characteristics of the finger; and to collect target fingerprint data based on the adjusted ultrasonic waves.

[0164] The memory 603 can be used to store the corresponding instruction program and related intermediate data.

[0165] Based on the above method, the relevant structural performance of electronic devices can be effectively utilized to improve the data processing speed of electronic devices and efficiently realize the dynamic acquisition and data processing of ultrasonic fingerprint data.

[0166] In this embodiment, the network communication port 601 can be a virtual port bound to different communication protocols, thereby enabling the sending or receiving of different data. For example, the network communication port can be a port responsible for web data communication, a port responsible for FTP data communication, or a port responsible for email data communication. Furthermore, the network communication port can also be a physical communication interface or communication chip. For example, it can be a wireless mobile network communication chip, such as GSM or CDMA; it can also be a Wi-Fi chip; or it can be a Bluetooth chip.

[0167] In this embodiment, the processor 602 can be implemented in any suitable manner. For example, the processor can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers, etc. This specification is not limiting.

[0168] In this embodiment, the memory 603 may include multiple layers. In a digital system, anything that can store binary data can be a memory. In an integrated circuit, a circuit with storage function but no physical form is also called a memory, such as RAM, FIFO, etc. In a system, a storage device with a physical form is also called a memory, such as a memory stick, TF card, etc.

[0169] This specification also provides a computer-readable storage medium based on the above-described dynamic acquisition method for ultrasonic fingerprint data. The computer-readable storage medium stores computer program instructions that, when executed, implement the following steps: acquiring contact pressure information of the current finger relative to the fingerprint acquisition area and / or surface characteristic information of the finger; adjusting the ultrasonic wave emission parameters according to the contact pressure information and / or the surface characteristic information of the finger; and acquiring target fingerprint data based on the adjusted ultrasonic waves.

[0170] In this embodiment, the storage medium includes, but is not limited to, Random Access Memory (RAM), Read-Only Memory (ROM), cache, hard disk drive (HDD), or memory card. The memory can be used to store computer program instructions. The network communication unit can be an interface configured according to standards specified in the communication protocol for network connection communication.

[0171] In this embodiment, the specific functions and effects implemented by the program instructions stored in the computer-readable storage medium can be explained in comparison with other embodiments, and will not be repeated here.

[0172] This specification also provides a computer program product, which includes at least a computer program that, when executed by a processor, performs the following method steps: acquiring contact pressure information of the current finger relative to the fingerprint acquisition area and / or surface characteristic information of the finger; adjusting the emission parameters of the ultrasonic wave based on the contact pressure information and / or the surface characteristic information of the finger; and acquiring target fingerprint data based on the adjusted ultrasonic wave.

[0173] See Figure 7 As shown in the embodiments of this specification, a dynamic acquisition device for ultrasonic fingerprint data is also provided. This device may specifically include the following structural modules:

[0174] The acquisition module 701 can be used to acquire the contact pressure information of the current finger relative to the fingerprint acquisition area and / or the surface characteristic information of the finger.

[0175] The adjustment module 702 can be specifically used to adjust the ultrasonic wave emission parameters based on the contact pressure information and / or the surface characteristics of the finger.

[0176] The acquisition module 703 can be used to acquire target fingerprint data based on adjusted ultrasonic waves.

[0177] In some embodiments, the ultrasonic wave may specifically include a focused wave;

[0178] Accordingly, the emission parameters of the ultrasonic wave may specifically include: frequency and / or phase, etc.

[0179] In some embodiments, the ultrasonic wave may specifically include a plane wave;

[0180] Accordingly, the emission parameters of the ultrasonic wave may specifically include: frequency, etc.

[0181] In some embodiments, the surface characteristic information may specifically include at least one of the following: roughness, smoothness, humidity, etc.

[0182] In some embodiments, when the adjustment module 702 is specifically implemented, it can adjust the ultrasonic emission parameters according to the contact pressure information and / or the surface characteristic information of the finger in the following manner: when the contact pressure indicated by the contact pressure information is greater than a preset first pressure threshold, the frequency of the ultrasonic wave is reduced according to a first adjustment rule; when the contact pressure indicated by the contact pressure information is less than a preset second pressure threshold, the frequency of the ultrasonic wave is increased according to the first adjustment rule; wherein, the preset first pressure threshold is greater than the preset second pressure threshold.

[0183] In some embodiments, when the adjustment module 702 is specifically implemented, it can adjust the ultrasonic emission parameters according to the contact pressure information and / or the surface characteristic information of the finger in the following manner: when the roughness of the finger indicated by the surface characteristic information is greater than a preset first roughness threshold, the phase of the ultrasonic wave is increased according to a second adjustment rule; when the roughness of the finger indicated by the surface characteristic information is less than a preset second roughness threshold, the phase of the ultrasonic wave is decreased according to a second adjustment rule; wherein, the preset first roughness threshold is greater than the preset second roughness threshold.

[0184] In some embodiments, when the adjustment module 702 is specifically implemented, it can adjust the ultrasonic emission parameters according to the contact pressure information and / or the surface characteristic information of the finger in the following manner: when the humidity of the finger indicated by the surface characteristic information is greater than a preset first humidity threshold, the frequency of the ultrasonic wave is reduced according to a third adjustment rule; when the humidity of the finger indicated by the surface characteristic information is less than a preset second humidity threshold, the frequency of the ultrasonic wave is increased according to a third adjustment rule; wherein, the preset first humidity threshold is greater than the preset second humidity threshold.

[0185] In some embodiments, the above-described device can also be used to: determine a matching target angle scanning range; control an ultrasonic transducer to perform multi-angle scanning according to the target angle scanning range to obtain multiple first-type echo signals at different angles; and acquire target fingerprint data based on the multiple first-type echo signals.

[0186] In some embodiments, when the above-described device is specifically implemented, target fingerprint data can be obtained based on multiple first-type echo signals in the following manner: based on the multiple first-type echo signals, depth information at multiple angles of the finger surface is determined by calculating the signal propagation time; based on the multiple first-type echo signals, corresponding signal parameters are extracted; wherein, the signal parameters include at least one of the following: intensity, phase, and time delay; using the depth information at multiple angles and the corresponding signal parameters, target fingerprint data is obtained through data fusion.

[0187] In some embodiments, when the above-described device is specifically implemented, the target fingerprint data can be obtained by using depth information from multiple angles and corresponding signal parameters through data fusion in the following manner: the depth information from multiple angles is aligned and calibrated respectively to obtain multiple processed depth information; and a three-dimensional fingerprint image is constructed by combining the multiple processed depth information according to the signal parameters, which serves as the target fingerprint data.

[0188] In some embodiments, the above-described device can also be used to: determine a matching target frequency range and target phase range; control an ultrasonic transducer to perform multi-frequency and multi-phase scanning based on the target frequency range and target phase range to obtain multiple second-type echo signals; and acquire target fingerprint data based on the multiple second-type echo signals.

[0189] It should be noted that the units, devices, or modules described in the above embodiments can be implemented by computer chips or physical entities, or by products with certain functions. For ease of description, the above devices are described by dividing them into various modules according to their functions. Of course, in implementing this specification, the functions of each module can be implemented in one or more software and / or hardware, or a module that implements the same function can be implemented by a combination of multiple sub-modules or sub-units, etc. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection between the shown or discussed units can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0190] As can be seen from the above, the dynamic acquisition device for ultrasonic fingerprint data provided in the embodiments of this specification can determine and intelligently distinguish different situations according to the contact state of the finger, and adaptively and dynamically adjust the emission parameters of the ultrasonic waves. In this way, fingerprint data with fine surface features and small errors can be acquired based on the adjusted ultrasonic waves, so that subsequent fingerprint data processing such as fingerprint recognition can be accurately realized based on the fingerprint data.

[0191] In a specific scenario example, the dynamic acquisition method for ultrasonic fingerprint data provided in this manual can be used to achieve high-precision focused wave ultrasonic fingerprint detection. The specific implementation process can be found below.

[0192] In this example scenario, existing ultrasonic fingerprint detection methods have limitations in detail capture and resolution, making it difficult to obtain high-precision fingerprint images. Typically, only a single angle is detected, making it difficult to capture comprehensive fingerprint features. High-resolution detection results in slow frame rates and high power consumption, negatively impacting the user experience of fingerprint unlocking on portable devices.

[0193] To address the aforementioned issues and their root causes, this scenario example further considers the following: First, an adaptive control system can be introduced to dynamically adjust the emission frequency and phase of the focused wave based on finger contact pressure and surface characteristics, improving detection accuracy and reliability. Second, multi-dimensional focused wave scanning can be used to perform high-resolution fingerprint detection from multiple angles and directions, generating a more comprehensive and detailed fingerprint image. Furthermore, plane wave detection can be used to quickly determine the finger region, followed by high-precision detection using focused waves, improving detection speed and optimizing power consumption.

[0194] In practical implementation, the key modules involved in the hardware architecture include an adaptive focused wave control module, a pressure sensor, a surface characteristic sensor, an adaptive control unit, a plane wave transmitter, and a receiver.

[0195] The relative positions and connections of these modules can be described as follows: Pressure sensor and surface characteristic sensor: Installed below or around the fingerprint detection area, these sensors monitor the contact pressure and surface characteristics of the finger in real time. Signals from these sensors are connected to the adaptive control unit via a data bus. Adaptive control unit: Located at the core of the system, this unit receives data from the pressure and surface characteristic sensors, performs real-time calculations, and dynamically adjusts the focused wave emission frequency and phase. The adaptive control unit is connected to the adaptive focused wave control module via a high-speed communication interface. Adaptive focused wave control module: This module is connected to multiple ultrasonic transducers and is responsible for adjusting the emission frequency and phase of each transducer according to the instructions from the adaptive control unit. It uses a low-latency digital signal processing chip for signal transmission and control. Plane wave transmitter and receiver: Used for initial detection of the finger pressure area. The transmitter and receiver are typically located around the periphery of the fingerprint detection area to cover the entire area. The transmitter emits a plane wave onto the finger surface, and the receiver captures the reflected signal, connecting it to the adaptive control unit via a signal bus.

[0196] In terms of control methods, upon system startup, the plane wave transmitter and receiver are first initialized, setting the initial ultrasonic transmission frequency (e.g., 5 MHz) and phase (e.g., 0°). Simultaneously, pressure sensors and surface characteristic sensors begin monitoring the contact pressure of the finger (e.g., within the range of 0.1 N–1 N) and surface roughness.

[0197] First, rapid detection can be performed using plane waves. A plane wave transmitter emits a plane wave at a low frequency (e.g., 5 MHz) covering the entire fingerprint detection area. A receiver captures the reflected signal to initially determine the area where the finger is pressed. The criteria for this initial area determination can be whether the signal reflection time and intensity exceed a set threshold (e.g., signal strength > 50 dB).

[0198] Then, adaptive focused wave emission is performed. Specifically, after initially determining the area, the adaptive control unit adjusts the emission frequency (e.g., when the pressure is high, the emission frequency is adjusted to 10MHz to improve penetration) and phase (e.g., the phase is adjusted according to the roughness of the surface characteristic sensor to ensure signal consistency) of the focused wave based on the data from the pressure sensor. The emission parameters (frequency, phase, emission intensity) of each ultrasonic transducer are also dynamically adjusted to ensure that the focused wave can be efficiently concentrated on the fingerprint feature area.

[0199] The focused wave emission frequency can typically be set between 5MHz and 20MHz and can be dynamically adjusted based on finger contact pressure and surface characteristics. The focused wave emission phase is adjusted to compensate for signal differences between the surface characteristics and the transducer; the adjustment range is between 0° and 360°. The transducer emission parameters are dynamically adjusted based on the received reflected signal to ensure the focused wave energy is concentrated in the area most in need of detection.

[0200] Specifically, the pressure applied by a finger to the sensor surface directly affects the propagation path and signal quality of the ultrasonic waves. Excessive pressure can lead to excessive signal reflection or transmission, affecting image clarity; insufficient pressure results in inadequate contact and a weak signal. By detecting the pressure in real time using a pressure sensor, the system can dynamically adjust the emission parameters of the focused wave to adapt to different contact pressures. Low pressure (e.g., less than 0.2N): When the pressure sensor detects insufficient finger pressure and inadequate contact, the system reduces the ultrasonic wave emission frequency (e.g., from 8MHz to 5MHz) to minimize signal transmission and reflection losses, ensuring sufficient signal capture for imaging. High pressure (e.g., greater than 0.8N): When the pressure is high, the system increases the emission frequency (e.g., from 5MHz to 8MHz or higher) to ensure sufficient ultrasonic penetration and prevent signal distortion caused by excessive finger pressure.

[0201] Specifically, the surface roughness of a finger affects the reflection characteristics of ultrasound waves, especially when the surface is rough or has moisture, which can easily cause phase deviation in the reflected signal. By detecting the surface's moisture and roughness using a surface characteristic sensor, the system can dynamically adjust the phase of the focused wave to reduce noise interference and improve signal consistency. In high roughness cases (e.g., when the detected roughness value is greater than a preset threshold of 1.5), the system increases the phase compensation angle (e.g., from 0° to 45°) to avoid signal shift causing image blurring. In low roughness cases (if the surface is smooth and there is no significant interference from moisture, such as sweat (e.g., roughness less than a preset threshold of 0.5), the system can reduce the phase compensation (e.g., maintain at 0° or adjust only to 10°) to maintain signal accuracy and consistency.

[0202] Furthermore, depending on the specific circumstances, multi-angle focused wave scanning can be performed. For example, focused waves can scan a defined area at multiple angles (e.g., 0°, 30°, 60°, etc.). Specifically, at different angles, the system captures the intensity, phase, and time delay of the reflected signal, and determines the depth information of different points on the finger surface by calculating the signal propagation time. Then, data fusion and processing are performed. The depth information captured from different angles is fused, and algorithms are used to calibrate errors, generating a two-dimensional high-resolution fingerprint image. Finally, three-dimensional reconstruction is performed using the multi-dimensional scan data to generate a three-dimensional fingerprint image for comparison and identification. The angle range for multi-angle scanning is typically between 0° and 90°, increasing in 30° increments, and can be adjusted for finer angles as needed.

[0203] In practice, the following specific steps may be included:

[0204] 1. Plane wave rapid detection: Used to quickly emit plane waves to cover a large area of ​​fingerprint detection, receive reflected signals and make a preliminary judgment on the area where the finger is pressed.

[0205] a) Initialization: When the system starts, the plane wave transmitter and receiver are initialized, and the initial ultrasonic transmission frequency and phase are set.

[0206] b) Signal transmission: Plane wave transmission covers the entire fingerprint acquisition area, ensuring rapid detection of the presence of a finger with low power consumption.

[0207] c) Signal reception and processing: The receiver captures the reflected ultrasonic signals and performs preliminary processing (e.g., preprocessing); wherein the preliminary processing includes signal filtering and noise suppression to ensure that the detected signals are clear.

[0208] d) Preliminary area determination: Through the processed signal, the system can quickly determine the area pressed by the finger and send information to the adaptive focusing wave control module.

[0209] 2. Adaptive Focused Wave Control: By monitoring finger contact pressure in real time with a pressure sensor and detecting the roughness and humidity of the finger surface with a surface characteristic sensor, the emission frequency and phase of the focused wave are dynamically adjusted.

[0210] a) Initialization and Monitoring: During system initialization, the pressure sensor and surface characteristic sensor begin monitoring finger pressure and surface characteristics. This data is sent to the adaptive control unit in real time.

[0211] b) Dynamic parameter adjustment: The adaptive control unit dynamically adjusts the emission frequency and phase of the focused wave based on sensor data. For example, when the pressure of a finger contact is high, a higher frequency and intensity focused wave may be needed to ensure penetration and detection accuracy; while when the surface roughness of the finger is high, the phase may need to be adjusted to improve signal consistency.

[0212] c) High-precision emission: The adjusted focused wave is concentrated and emitted onto the detected finger contact area, improving detection accuracy and resolution. By adjusting the emission parameters of each transducer, the emission direction and energy concentration point of the ultrasonic transducer can be precisely controlled, enabling dynamic scanning of the focused wave.

[0213] d) Multi-frequency and multi-phase control: The system can simultaneously control the emission of ultrasonic waves at multiple frequencies and phases, enabling high-precision detection in complex environments. For example, the system can simultaneously emit high-frequency and low-frequency focused waves to capture fingerprint features at different depths.

[0214] 3. Multi-dimensional focused wave scanning: Enables multi-angle focused wave scanning of different areas of the finger, capturing more fingerprint details. Combining multi-dimensional scan data, algorithms generate 3D fingerprint images, improving recognition accuracy.

[0215] a) Multi-angle scanning: After initialization, the system begins multi-angle focused wave scanning of the finger. These angles include different emission and incident angles to ensure that more details of the finger surface are captured.

[0216] b) Data Acquisition and Processing: At each angle, the system captures the reflected focused wave signal and performs preliminary processing. This data includes the intensity, phase, and time delay of the reflected signal. By calculating the propagation time of each signal, depth information at different points on the finger surface can be determined.

[0217] c) Data fusion: Aligning and calibrating depth information acquired from different angles to eliminate errors caused by varying scanning angles. Algorithms are used to generate high-resolution two-dimensional fingerprint images to ensure image accuracy.

[0218] d) 3D Imaging: Data from multiple scans is used to reconstruct a 3D fingerprint image using algorithms. This process utilizes depth information from different angles to optimize and enhance the generated 3D fingerprint image, removing noise and errors, and improving image clarity and detail.

[0219] e) Fingerprint matching and recognition: Matching and recognizing 3D fingerprint images with a pre-stored fingerprint database, improving the accuracy and security of recognition by comparing 3D fingerprint features.

[0220] The above scenario examples verify the dynamic acquisition method of ultrasonic fingerprint data provided in this specification. By introducing and using pressure sensors and surface characteristic sensors, the emission parameters of the focused wave can be adjusted in real time, including adaptive adjustment of frequency and phase, thereby improving detection accuracy and reliability. Multi-angle focused wave scanning captures more fingerprint details and generates high-resolution and three-dimensional fingerprint images. Plane waves are also used for rapid region detection, followed by high-precision detection using focused waves, which improves detection speed and optimizes power consumption.

[0221] While this specification provides the steps of operation for the methods described in the embodiments or flowcharts, more or fewer steps may be included based on conventional or non-inventive means. The order of steps listed in the embodiments is merely one possible order of execution among many steps and does not represent the only possible order. In actual device or client product execution, the methods shown in the embodiments or drawings may be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment, or even a distributed data processing environment). The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, product, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, product, or apparatus. Without further limitations, the presence of other identical or equivalent elements in a process, method, product, or apparatus that includes said elements is not excluded. The terms "first," "second," etc., are used to denote names and do not indicate any particular order.

[0222] Those skilled in the art will also know that, besides implementing the controller using purely computer-readable program code, the same functions can be achieved by logically programming the method steps, making the controller function as logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers (PLCs), and embedded microcontrollers. Therefore, such a controller can be considered a hardware component, and the devices within it used to implement various functions can also be considered structures within that hardware component. Alternatively, the devices used to implement various functions can be considered as both software modules implementing the method and structures within a hardware component.

[0223] This specification can be described in the general context of computer-executable instructions that are executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc., that perform a specific task or implement a specific abstract data type. This specification can also be practiced in distributed computing environments, where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer-readable storage media, including storage devices.

[0224] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this specification can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solutions of this specification can essentially be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, mobile terminal, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments of this specification.

[0225] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. This specification can be used in numerous general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable electronic devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices, etc.

[0226] Although this specification has been described by way of examples, those skilled in the art will recognize that many variations and modifications are possible without departing from the spirit of this specification, and it is intended that the appended claims cover such variations and modifications without departing from the spirit of this specification.

Claims

1. A method for dynamic acquisition of ultrasonic fingerprint data, characterized in that, include: Based on plane wave detection to determine whether the user is currently pressing the fingerprint collection area; When determining the user's current fingerprint collection area, obtain the contact pressure information of the current finger relative to the fingerprint collection area and / or the surface characteristic information of the finger; The surface characteristic information includes at least: roughness or smoothness; Switching from plane wave mode to focused wave mode; adjusting the ultrasonic wave emission parameters based on the contact pressure information and / or finger surface characteristics information; including: determining the type of ultrasonic wave currently being used; determining suitable ultrasonic wave emission parameters for adjustment based on the type of ultrasonic wave currently being used; and then adjusting the corresponding ultrasonic wave emission parameters based on the suitable ultrasonic wave emission parameters, according to the contact pressure information and / or finger surface characteristics information; the type of ultrasonic wave includes: focused wave and / or plane wave. Target fingerprint data is acquired based on the adjusted ultrasound.

2. The method according to claim 1, characterized in that, The transmission parameters of the ultrasonic wave include: frequency and / or phase.

3. The method according to claim 2, characterized in that, The surface characteristic information also includes humidity.

4. The method according to claim 1, characterized in that, Based on the contact pressure information and / or the surface characteristics of the finger, adjust the ultrasonic wave emission parameters, including: When the contact pressure indicated by the contact pressure information is greater than a preset first pressure threshold, the frequency of the ultrasonic wave is reduced according to the first adjustment rule. When the contact pressure indicated by the contact pressure information is less than a preset second pressure threshold, the frequency of the ultrasonic wave is increased according to the first adjustment rule; wherein the preset first pressure threshold is greater than the preset second pressure threshold.

5. The method according to claim 3, characterized in that, Based on the contact pressure information and / or the surface characteristics of the finger, adjust the ultrasonic wave emission parameters, including: When the surface characteristic information indicates that the roughness of the finger is greater than a preset first roughness threshold, the phase of the ultrasonic wave is increased according to the second adjustment rule. When the surface characteristic information indicates that the roughness of the finger is less than a preset second roughness threshold, the phase of the ultrasonic wave is reduced according to the second adjustment rule; wherein the preset first roughness threshold is greater than the preset second roughness threshold.

6. The method according to claim 3, characterized in that, Based on the contact pressure information and / or the surface characteristics of the finger, adjust the ultrasonic wave emission parameters, including: When the humidity of the finger indicated by the surface characteristic information is greater than a preset first humidity threshold, the frequency of the ultrasonic wave is reduced according to the third adjustment rule. When the humidity of the finger indicated by the surface characteristic information is less than a preset second humidity threshold, the frequency of the ultrasonic wave is increased according to a third adjustment rule; wherein the preset first humidity threshold is greater than the preset second humidity threshold.

7. The method according to claim 1, characterized in that, The method further includes: Determine the matching target angle scanning range; Based on the target angle scanning range, the ultrasonic transducer is controlled to perform multi-angle scanning to obtain multiple first-type echo signals at different angles. Target fingerprint data is obtained based on multiple Type I echo signals.

8. The method according to claim 7, characterized in that, Target fingerprint data is obtained based on multiple Type I echo signals, including: Based on multiple Type I echo signals, the depth information of the finger surface at multiple angles is determined by calculating the signal propagation time. Based on multiple Type I echo signals, corresponding signal parameters are extracted; wherein, the signal parameters include at least one of the following: intensity, phase, and time delay; By utilizing depth information from multiple angles and corresponding signal parameters, target fingerprint data is obtained through data fusion.

9. The method according to claim 8, characterized in that, By utilizing depth information from multiple angles and corresponding signal parameters, target fingerprint data is obtained through data fusion, including: Alignment and calibration processes are performed on depth information from multiple angles to obtain multiple processed depth information; Based on the signal parameters, a three-dimensional fingerprint image is constructed by combining multiple processed depth information, which serves as the target fingerprint data.

10. The method according to claim 1, characterized in that, The method further includes: Determine the matching target frequency range and target phase range; Based on the target frequency range and the target phase range, the ultrasonic transducer is controlled to perform multi-frequency and multi-phase scanning to obtain multiple second-type echo signals. Target fingerprint data is obtained based on multiple Type II echo signals.

11. A dynamic acquisition device for ultrasonic fingerprint data, characterized in that, include: The acquisition module is used to detect whether the user is currently pressing the fingerprint acquisition area based on plane waves; When determining the user's current fingerprint collection area, obtain the contact pressure information of the current finger relative to the fingerprint collection area and / or the surface characteristic information of the finger; The surface characteristic information includes at least: roughness or smoothness; An adjustment module is used to switch from plane wave mode to focused wave mode; and to adjust the ultrasonic wave emission parameters based on the contact pressure information and / or the surface characteristics of the finger. Specifically, the adjustment module is used to: determine the type of ultrasonic wave currently being used; determine suitable ultrasonic wave emission parameters based on the currently used ultrasonic wave type; and then adjust the corresponding ultrasonic wave emission parameters based on the suitable ultrasonic wave emission parameters, according to the contact pressure information and / or the surface characteristics of the finger. The ultrasonic wave type includes focused wave and / or plane wave. The acquisition module is used to acquire target fingerprint data based on the adjusted ultrasonic waves.

12. An electronic device, characterized in that, It includes a processor and a memory for storing processor-executable instructions, wherein the processor, when executing the instructions, implements the steps of the method according to any one of claims 1 to 10.

13. A computer-readable storage medium, characterized in that, It stores computer instructions that, when executed by a processor, implement the steps of the method according to any one of claims 1 to 10.

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