Ultrasonic-based fingerprint data acquisition method, device and electronic equipment

Abstract

The present specification provides an ultrasonic-based fingerprint data acquisition method and device and electronic equipment, which can be used in the field of fingerprint recognition technology. Based on the method, the pollutant information and / or humidity information of the finger can be acquired first; then the matching target frequency band is determined according to the pollutant information and / or humidity information of the finger; and the target fingerprint data is acquired by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band. By analyzing and according to the actual environmental conditions of the finger, the matching target frequency band is intelligently determined; and then the target fingerprint data is acquired by controlling the emission of corresponding ultrasonic signals based on the target frequency band, so that the error interference caused by environmental factors such as finger pollutants and moisture can be effectively reduced, and the fingerprint data containing one or more depth information can be accurately collected, which can be well applied to subsequent fingerprint data processing such as fingerprint recognition.

Description

Technical Field

[0001] This specification pertains to the field of fingerprint recognition technology, and particularly relates to methods, devices, and electronic devices for acquiring fingerprint data based on ultrasound. Background Technology

[0002] Existing fingerprint data acquisition methods mostly adopt a uniform approach without differentiation, collecting fingerprint data for subsequent fingerprint data processing such as fingerprint recognition. However, the environmental conditions during fingerprint data collection often vary significantly across different scenarios, leading to considerable uncertainty in the data quality of fingerprint data collected using the above methods, which in turn affects subsequent fingerprint data processing.

[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 acquiring fingerprint data based on ultrasound, which can effectively reduce the error interference caused by environmental factors such as finger contaminants and moisture during fingerprint data acquisition, and obtain high-quality fingerprint data.

[0005] This specification provides a method for acquiring fingerprint data based on ultrasound, including:

[0006] Obtain information on contaminants and / or humidity on the fingers;

[0007] Based on the contaminant information and / or humidity information of the fingers, determine the matching target frequency band;

[0008] Based on the target frequency band, the target fingerprint data is obtained by controlling the ultrasonic transducer to emit corresponding ultrasonic signals.

[0009] In one embodiment, obtaining information about contaminants and / or humidity on the finger includes:

[0010] Control the ultrasonic transducer to emit an initial ultrasonic signal and receive the corresponding initial echo signal;

[0011] Based on the initial echo signal, obtain information on contaminants and / or humidity on the finger.

[0012] In one embodiment, the method further includes:

[0013] Collect current environmental information;

[0014] Based on the current environmental information, determine the matching initial frequency band;

[0015] The initial ultrasonic signal is determined based on the initial frequency band.

[0016] In one embodiment, obtaining contaminant information of the finger based on the initial echo signal includes:

[0017] Determine the signal strength and / or signal-to-noise ratio of the initial echo signal based on the initial echo signal;

[0018] Determine whether there is contaminant on the finger based on the signal strength and / or signal-to-noise ratio of the initial echo signal;

[0019] If contaminants are confirmed on the finger, calculate the attenuation of the signal strength of the initial echo signal and / or the decrease in the signal-to-noise ratio.

[0020] Based on the signal strength attenuation and / or the decrease in signal-to-noise ratio, pollutant information is determined by querying a preset pollutant mapping table.

[0021] In one embodiment, the contaminant information includes at least one of the following: contaminant type, contaminant thickness, contaminant area, and contamination location.

[0022] In one embodiment, determining a matching target frequency band based on contaminant information from the finger includes:

[0023] Based on the contaminant information on the finger, the target frequency band that matches is determined by querying a preset set of contaminant frequency band matching rules.

[0024] In one embodiment, the method further includes:

[0025] Based on the contaminant information and / or humidity information of the fingers, determine the matching target signal intensity;

[0026] Based on the target signal strength, the target fingerprint data is obtained by controlling the ultrasonic transducer to emit corresponding ultrasonic signals.

[0027] In one embodiment, the target frequency band includes multiple sub-target frequency bands;

[0028] Accordingly, based on the target frequency band, the ultrasonic transducer is controlled to emit corresponding ultrasonic signals to acquire multiple sub-target fingerprint data; among them, one sub-target fingerprint data corresponds to an ultrasonic signal of one sub-target frequency band.

[0029] In one embodiment, after acquiring fingerprint data from multiple sub-targets, the method further includes:

[0030] Key features were extracted from the fingerprint data of multiple sub-targets.

[0031] Based on the preset fusion rules, the reliability weight coefficients of key features are determined;

[0032] Based on the reliability weighting coefficient, multiple key features are fused in multiple frequency bands to obtain a target fingerprint image that meets the requirements; wherein, the target fingerprint image is used for fingerprint recognition.

[0033] In one embodiment, after acquiring fingerprint data from multiple sub-targets, the method further includes:

[0034] Using multiple sub-target fingerprint data, fingerprint features are compared with corresponding user fingerprint feature templates in multiple frequency bands to obtain fingerprint feature comparison results for multiple frequency bands;

[0035] Based on the contaminant information and / or humidity information of the fingers, the fingerprint feature comparison results of multiple frequency bands are weighted and calculated to obtain the target fingerprint feature comparison result;

[0036] Based on the comparison results of the target fingerprint features, determine whether the fingerprint recognition is successful.

[0037] In one embodiment, the method further includes:

[0038] According to the preset acquisition rules, the ultrasonic transducer is controlled to emit ultrasonic signals of multiple preset frequency bands sequentially or in multiple batches to acquire fingerprint data of multiple frequency bands.

[0039] Based on fingerprint data from multiple frequency bands, construct and store user fingerprint feature templates for multiple frequency bands.

[0040] This specification also provides a method for acquiring fingerprint data based on ultrasound, including:

[0041] Control the ultrasonic transducer to emit an initial ultrasonic signal and receive the corresponding initial echo signal;

[0042] Based on the initial echo signal, the matching target frequency band is determined;

[0043] Based on the target frequency band, the target fingerprint data is obtained by controlling the ultrasonic transducer to emit corresponding ultrasonic signals.

[0044] In one embodiment, the target frequency band includes multiple sub-target frequency bands;

[0045] Accordingly, based on the target frequency band, the ultrasonic transducer is controlled to emit corresponding ultrasonic signals to acquire multiple sub-target fingerprint data; among them, one sub-target fingerprint data corresponds to an ultrasonic signal of one sub-target frequency band.

[0046] This specification also provides a method for acquiring fingerprint data based on ultrasound, including:

[0047] Acquire information on contaminants and / or humidity in the fingerprint collection area;

[0048] Based on the contaminant information and / or humidity information on the fingerprint collection area, the matching target frequency band is determined;

[0049] Based on the target frequency band, the target fingerprint data is obtained by controlling the ultrasonic transducer to emit corresponding ultrasonic signals.

[0050] This specification also provides a method for acquiring fingerprint data based on ultrasound, including:

[0051] Based on the first frequency band, the first ultrasonic signal is emitted by controlling the ultrasonic transducer to obtain the first fingerprint data;

[0052] Determine whether the first fingerprint data meets the preset processing requirements;

[0053] If the first fingerprint data does not meet the preset processing requirements, the system switches to the second frequency band and controls the ultrasonic transducer to emit a second ultrasonic signal to acquire the second fingerprint data.

[0054] This specification also provides an ultrasonic fingerprint data acquisition device, comprising:

[0055] The first acquisition module is used to acquire information about contaminants and / or humidity on the fingers;

[0056] The determination module is used to determine the matching target frequency band based on the contaminant information and / or humidity information of the finger;

[0057] The second acquisition module is used to acquire target fingerprint data by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band.

[0058] 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 ultrasonic-based fingerprint data acquisition method.

[0059] This specification also provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the steps of the ultrasonic-based fingerprint data acquisition method.

[0060] Based on the ultrasonic fingerprint data acquisition method, apparatus, and electronic device provided in this specification, in specific implementation, information on finger contaminants and / or humidity can be acquired first; then, based on the finger contaminant and / or humidity information, a matching target frequency band can be determined; according to the target frequency band, the ultrasonic transducer is controlled to emit corresponding ultrasonic signals to acquire target fingerprint data. By analyzing and distinguishing different situations based on the actual environmental conditions of the finger, a matching target frequency band is intelligently determined; and then, based on the target frequency band, the target fingerprint data is acquired by controlling the emission of corresponding ultrasonic signals. This effectively reduces the error interference caused by environmental factors such as finger contaminants and moisture during fingerprint data acquisition, accurately acquiring fingerprint data containing one or more depth information, which can be well applied to subsequent fingerprint data processing such as fingerprint recognition. Attached Figure Description

[0061] 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.

[0062] Figure 1 This is a flowchart illustrating an embodiment of an ultrasonic fingerprint data acquisition method provided in this specification.

[0063] Figure 2 This is a schematic diagram illustrating an embodiment of the ultrasonic fingerprint data acquisition method provided in this specification, applied in a scenario example.

[0064] Figure 3 This is a schematic diagram illustrating an embodiment of the ultrasonic fingerprint data acquisition method provided in this specification, applied in a scenario example.

[0065] Figure 4 This is a schematic diagram illustrating an embodiment of the ultrasonic fingerprint data acquisition method provided in this specification, applied in a scenario example.

[0066] Figure 5 This is a flowchart illustrating another embodiment of the ultrasonic fingerprint data acquisition method provided in this specification.

[0067] Figure 6 This is a schematic diagram of the structural composition of an electronic device provided in one embodiment of this specification;

[0068] Figure 7 This is a schematic diagram of the structural composition of an ultrasonic fingerprint data acquisition device provided in one embodiment of this specification. Detailed Implementation

[0069] 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.

[0070] 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.

[0071] 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.

[0072] See Figure 1 As shown in the embodiments of this specification, a method for acquiring fingerprint data based on ultrasound is provided. Specifically, this method may include the following:

[0073] S101: Acquire information on contaminants and / or humidity on the fingers;

[0074] S102: Determine the matching target frequency band based on the contaminant information and / or humidity information of the fingers;

[0075] S103: Based on the target frequency band, the ultrasonic transducer is controlled to emit corresponding ultrasonic signals to acquire target fingerprint data.

[0076] The aforementioned method for dynamically acquiring ultrasonic fingerprint data can be applied to a fingerprint recognition device (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.

[0077] 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.

[0078] 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.

[0079] 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).

[0080] Specifically, the aforementioned ultrasonic transducer includes at least the following structures: piezoelectric element, electrode, matching layer, backing layer, etc.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] The aforementioned transmitting circuit includes at least a signal generator. The signal generator can generate electrical signals to control the ultrasonic transducer to emit corresponding ultrasonic signals. The signal transmitter may include an oscillator, which can adjust the frequency of the ultrasonic signals emitted by the ultrasonic transducer. In this embodiment, the frequency range of the ultrasonic signals emitted by the ultrasonic transducer controlled by the signal generator is greater than or equal to 1MHz and less than or equal to 20MHz.

[0087] Furthermore, the aforementioned transmitting circuit may also include a power amplifier and an impedance matching network. The power amplifier amplifies the electrical signal generated by the signal generator and then feeds the amplified electrical signal into the ultrasonic transducer. The impedance matching network can be a transformer, LC circuit, or other means to adjust the impedance between the ultrasonic transducer and the circuit (e.g., input impedance, output impedance, etc.) to reduce power loss and enable the ultrasonic transducer to receive as much energy as possible.

[0088] The aforementioned receiving circuit includes at least a detector (e.g., an envelope detector) and a digital-to-analog converter (ADC). The envelope detector is used to extract envelope information from the echo signal received by the ultrasonic transducer, as well as to detect the intensity and time delay of the echo signal, and analyze the propagation and reflection of ultrasonic waves in the medium. The ADC is used to convert the received analog signal (e.g., the echo signal) into a corresponding digital signal for further data processing.

[0089] Furthermore, the receiving circuit may further include a preamplifier and a filter. The preamplifier amplifies the echo signal received by the ultrasonic transducer. In this embodiment, a low-noise amplifier (LNA) can be used as the preamplifier to avoid introducing excessive noise during signal amplification and ensure signal quality. The filter can be used to filter out noise signals and unwanted frequency bands from the received signal. In this embodiment, the transmission frequency of the ultrasonic wave can be used as the center frequency of the filter to ensure that the filtered signal is the reflected signal of the relevant ultrasonic wave.

[0090] 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.

[0091] The aforementioned ultrasonic modes include: focused wave mode and plane wave mode.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] The aforementioned fingerprint recognition device may further include an environmental sensor; wherein the environmental sensor is used to collect relevant environmental information. This environmental information may, for example, include information about contaminants and humidity on the object being detected (e.g., a finger) when the user presses the fingerprint collection area; furthermore, it may include other information that can directly or indirectly reflect the aforementioned contaminant and humidity information, such as weather information, temperature information, seasonal information, and location information.

[0097] Specifically, the aforementioned environmental sensors may include smart cameras; correspondingly, the smart camera can capture images of the surface of the object being detected, and then a pollutant detection model can be used to perform image recognition processing on the images to obtain the corresponding pollutant information. The aforementioned environmental sensors may also include hygrometers; correspondingly, the hygrometer can also collect the humidity value of the area closest to the fingerprint collection area of ​​the object being detected, as the corresponding humidity information.

[0098] Of course, it should be noted that the environmental sensors listed above are only illustrative. In actual implementation, other types of devices can be introduced and used as environmental sensors depending on the specific circumstances and processing requirements. Furthermore, fingerprint recognition devices can also obtain the required environmental information by combining the echo signals received by the ultrasonic transducer with previously emitted ultrasonic signals through corresponding calculations.

[0099] A control unit (e.g., a microcontroller chip) can also be installed below the fingerprint acquisition area. The control unit can be electrically connected to the environmental sensor, transmitting circuit, etc.

[0100] 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.

[0101] Based on the aforementioned fingerprint recognition device, when a user presses the fingerprint collection area, the contaminant information and / or humidity information of the object being detected (e.g., a finger) can be determined first through an environmental sensor or based on the received echo signal. Then, based on the contaminant information and / or humidity information, different environmental conditions can be distinguished, and a matching target frequency band can be determined. Based on the target frequency band, the ultrasonic transducer is controlled to emit a corresponding ultrasonic signal to obtain target fingerprint data with high quality and small error.

[0102] Specifically, when there are contaminants on the surface, the contaminants cover the skin, making it impossible to directly collect fingerprint details from the skin surface. In this case, low-frequency ultrasonic signals (e.g., 1-5MHz) can be used first to increase the penetrating power of the ultrasonic signals, so as to penetrate the surface contaminants and reach deeper skin layers to capture fingerprint features in deeper layers of the skin (e.g., large ridge lines, the overall shape of the ridge lines, etc.) as a supplement and aid, so as to obtain high-quality fingerprint data that meets the requirements of subsequent processing.

[0103] In cases of high surface humidity, since surface moisture can interfere with ultrasonic signals, it is advisable to use high-frequency ultrasonic signals (e.g., 10-20MHz) to avoid moisture interference and capture fingerprint details on the skin surface (e.g., fine ridges, sweat pores, and fingerprint details) to obtain high-quality fingerprint data that meets the requirements for subsequent processing.

[0104] For surfaces free of contaminants and with normal humidity, high-frequency ultrasonic signals can be used to obtain fingerprint data with high resolution that contains identifiable fingerprint information of the skin surface. Alternatively, mid-frequency or normal-frequency ultrasonic signals (e.g., 5-10MHz) can be used to balance resolution and penetration, obtaining fingerprint data with good results that contains medium-detail features of the fingerprint (e.g., mid-layer ridges, fingerprint lines, etc.) as well as gap information between high-frequency and low-frequency bands.

[0105] In some embodiments, specifically, the process can begin by controlling the ultrasonic transducer to emit a corresponding plane wave as the initial ultrasonic signal, based on a plane wave mode, to detect whether the user is currently pressing the fingerprint collection area. Once it is determined that the user is currently pressing the fingerprint collection area, relevant contaminant information and / or humidity information are acquired, and a matching target frequency band is determined based on the contaminant information and / or humidity information. Then, based on the target frequency band, the ultrasonic transducer is controlled to emit a corresponding ultrasonic signal to acquire the target fingerprint data.

[0106] In practice, the user's pressing position can be determined based on the detection results of the plane wave; then, the emission angle of the ultrasonic transducer can be adjusted according to the user's pressing position to align with the user's pressing position; and finally, according to the target frequency band, the ultrasonic transducer can be controlled to emit a corresponding focused wave to obtain the target fingerprint data.

[0107] In this way, we can first use plane wave detection, which has low power consumption and high speed, to determine whether a user has pressed the fingerprint collection area; after confirming that a user has pressed the fingerprint collection area, we can then use an adjusted focused wave, which has higher power consumption but higher accuracy and matches the current pollutant information and / or humidity information, to collect the required fingerprint data. This way, we can simultaneously take into account power consumption and accuracy and collect high-quality target fingerprint data.

[0108] In some embodiments, the pollutant information may specifically include at least one of the following: pollutant type, pollutant thickness, pollutant area, pollutant location, etc.

[0109] The types of contaminants mentioned above may specifically include at least one of the following: dirt, grease, gravel, etc.

[0110] Of course, the pollutant information and types listed above are only illustrative. In actual implementation, other pollutant information and types may be included depending on the specific application scenario and treatment requirements. This manual does not limit this.

[0111] It should be noted that different types of pollutants and varying pollutant thicknesses will have different effects on ultrasonic wave reflection. Accordingly, the frequency band of the ultrasonic waves can be adjusted differently for different types and thicknesses of pollutants to determine a target frequency band with a higher degree of matching. Specific adjustment methods will be explained later.

[0112] In some embodiments, the acquisition of contaminant information and / or humidity information of the finger described above may include the following:

[0113] S1: Controls the ultrasonic transducer to emit an initial ultrasonic signal and receive the corresponding initial echo signal;

[0114] S2: Based on the initial echo signal, acquire information about contaminants and / or humidity on the finger.

[0115] The initial ultrasonic signal mentioned above can be a plane wave signal.

[0116] In practice, the environmental conditions of the target object can be estimated based on the current environmental information, and a suitable plane wave signal can be determined as the initial ultrasonic signal based on the estimation results. Then, the ultrasonic transducer is controlled to emit the initial ultrasonic signal to perform preliminary detection on the target object, and the corresponding initial echo signal is received. The preliminary detection may include: fingerprint area pressing detection and / or environmental condition detection.

[0117] In practice, after receiving the initial echo signal, the system can first determine whether the user is currently pressing the fingerprint collection area based on the initial echo signal.

[0118] If it is determined that the user is currently pressing the fingerprint collection area, further information on contaminants and / or humidity of the object being detected can be obtained. Conversely, if it is determined that the user is not currently pressing the fingerprint collection area, subsequent data processing can be stopped directly, and the device can enter sleep mode to save energy.

[0119] Specifically, the acquisition of pollutant information and / or humidity information of the target object may include: selectively collecting pollutant information and / or humidity information of the target object through environmental sensors and acquiring such information based on the corresponding sensor signals; and / or determining the pollutant information and / or humidity information of the target object by calculating and based on the signal quality change data of the initial echo signal.

[0120] Furthermore, once it's determined that the user is currently pressing the fingerprint collection area, the corresponding positioning algorithm can be used based on the initial echo signal to determine the user's current pressing position within the fingerprint collection area. Subsequently, based on this pressing position, information about contaminants and / or humidity, or target fingerprint data, can be collected more accurately.

[0121] In some embodiments, see Figure 2 As shown, in specific implementations, the method may also include the following:

[0122] S1: Collect current environmental information;

[0123] S2: Based on the current environmental information, determine the matching initial frequency band;

[0124] S3: Determine the initial ultrasonic signal based on the initial frequency band.

[0125] In practice, the current environmental information can be collected first through environmental sensors; then, the environmental condition of the object to be detected can be estimated based on the current environmental information; and based on the estimated environmental condition, the matching initial frequency band can be determined from multiple preset detection frequency bands.

[0126] Specifically, based on the prediction results, if the environmental conditions are determined to be characterized by high pollutant levels and low humidity, a lower-frequency detection band can be selected from a set of preset detection bands as the initial frequency band. Conversely, if the environmental conditions are determined to be characterized by low pollution and high humidity, a higher-frequency detection band can be selected from a set of preset detection bands as the initial frequency band. Then, based on the initial frequency band, the initial ultrasonic signal can be determined, and the ultrasonic transducer can be controlled to emit the initial ultrasonic signal for targeted preliminary detection.

[0127] In some embodiments, see Figure 3 As shown, the above method of obtaining contaminant information from a finger based on the initial echo signal can, in practice, include the following:

[0128] S1: Determine the signal strength and / or signal-to-noise ratio of the initial echo signal based on the initial echo signal;

[0129] S2: Determine whether there is contaminant on the finger based on the signal strength and / or signal-to-noise ratio of the initial echo signal;

[0130] S3: If it is determined that there is contamination on the finger, calculate the attenuation value of the signal strength of the initial echo signal and / or the decrease in signal-to-noise ratio;

[0131] S4: Based on the signal strength attenuation and / or the signal-to-noise ratio decrease, determine the pollutant information by querying the preset pollutant mapping table.

[0132] In practice, the signal strength and / or signal-to-noise ratio (SNR) of the initial echo signal can be compared with preset reference template data (e.g., template reference data for signal strength and template reference data for signal-to-noise ratio). Based on the comparison results, if it is determined that the signal strength of the initial echo signal is weaker than the reference template data (e.g., the signal strength of the initial echo signal is less than the preset template reference data for signal strength, and the difference between the two is greater than or equal to a preset first threshold), and / or, the SNR of the initial echo signal decreases relative to the reference template data (e.g., the SNR of the initial echo signal is less than the template reference data for signal-to-noise ratio, and the difference between the two is greater than or equal to a preset second threshold), then it can be determined that the detected object contains contaminants. The aforementioned preset reference template data can be determined in advance through experimental testing on a detected object without contaminants and with normal humidity.

[0133] Based on the comparison results, if it is determined that the object being tested is free of contaminants, the required target fingerprint data can be obtained directly from the initial echo signal. Alternatively, the humidity of the object can be further detected based on the initial echo signal and / or sensor signals collected by environmental sensors; based on the humidity monitoring results, it can be determined whether the target frequency band of the ultrasonic signal needs to be redefined, and the target fingerprint data can be obtained based on the target frequency band.

[0134] Based on the comparison results, if it is determined that the object being tested contains pollutants, the signal strength attenuation value and / or signal-to-noise ratio decrease value of the initial echo signal can be further calculated based on the preset reference template data; then, by querying the preset pollutant mapping relationship table, pollutant information such as pollutant type and pollutant thickness can be determined.

[0135] The preset pollutant mapping table contains multiple data groups; each data group corresponds to a type of pollutant and includes the range of signal intensity attenuation and signal-to-noise ratio attenuation for multiple thickness intervals.

[0136] Before implementation, fingerprint recognition equipment can be used to conduct experimental tests on the sample detection objects regarding different types of pollutants and different thicknesses; and a large amount of experimental test data can be collected; based on the experimental test data, a preset pollutant mapping relationship table can be constructed through cluster learning.

[0137] In addition, in specific implementation, multiple ultrasonic transducers can be controlled simultaneously to generate multiple initial ultrasonic signals and receive multiple corresponding initial echo signals; based on preset reference template data, initial echo signals with weakened signal strength and / or decreased signal-to-noise ratio are selected from the multiple initial echo signals as abnormal signals; and based on the ultrasonic transducers corresponding to the above abnormal signals, pollutant information such as pollutant location and pollutant area is determined.

[0138] In some embodiments, the above-mentioned determination of a matching target frequency band based on the contaminant information of the finger may specifically include: determining a matching target frequency band by querying a preset contaminant frequency band matching rule set based on the contaminant information of the finger.

[0139] The preset pollutant frequency band matching rule set includes multiple preset matching rules, each corresponding to at least one pollutant type. Furthermore, each preset matching rule may include multiple preset matching frequency bands, each corresponding to a thickness range. Specifically, each preset matching rule may include three preset matching frequency bands: high-frequency, mid-frequency, and low-frequency. For different pollutant types, the aforementioned preset matching frequency bands may correspond to different frequency ranges.

[0140] The aforementioned pre-defined pollutant matching frequency band rule set can be specifically determined in advance through extensive experimental tests on sample detection objects regarding different pollutant conditions.

[0141] Specifically, based on the type of pollutant, a matching preset rule can be determined from a set of preset pollutant frequency band matching rules as the target matching rule; then, based on the thickness of the pollutant, a matching preset frequency band can be determined from the target matching rule as the target frequency band.

[0142] In some embodiments, after determining the matching target frequency band based on pollutant information, the target frequency band can be adjusted based on humidity information to obtain an adjusted target frequency band that takes into account both pollutant and humidity information. Then, the adjusted target frequency band is used to control the ultrasonic transducer to emit corresponding ultrasonic signals to acquire target fingerprint data, thereby obtaining target fingerprint data that eliminates interference from both pollutants and moisture.

[0143] Specifically, you can first check if the humidity information is greater than the humidity information template reference data. If the humidity information is less than or equal to the humidity information template reference data, the humidity can be determined to be normal, and in this case, no adjustment to the target frequency band is necessary.

[0144] If the humidity information is determined to be greater than the humidity information template reference data, it can be determined that the humidity is high. In this case, the relatively larger and later half of the frequency band can be extracted from the target frequency band as the adjusted target frequency band.

[0145] This allows us to determine the target frequency band that matches both pollutant and humidity information.

[0146] In some embodiments, the method may further include the following:

[0147] S1: Determine the matching target signal intensity based on the contaminant information and / or humidity information of the finger;

[0148] S2: Based on the target signal strength, the ultrasonic transducer is controlled to emit a corresponding ultrasonic signal to obtain the target fingerprint data.

[0149] Specifically, experimental tests have shown that when the surface of the object being tested has a lot of contaminants or high humidity, increasing the intensity of the ultrasonic signal can penetrate the contaminants or moisture to a certain extent and collect fingerprint data with better results.

[0150] Accordingly, in specific implementation, based on pollutant information and / or humidity information, when it is determined that there are pollutants on the surface of the object to be detected, and / or the humidity is high, the signal intensity can be increased accordingly based on the thickness of the pollutants and / or the humidity value to obtain a matching target signal intensity.

[0151] In some embodiments, a matching target signal intensity and a matching target frequency band can be determined based on pollutant information and / or humidity information; then, based on the target signal intensity and target frequency band, the ultrasonic transducer is controlled to emit a corresponding ultrasonic signal to obtain target fingerprint data.

[0152] In some embodiments, during the process of acquiring target fingerprint data by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band, the emission intensity and / or frequency of the ultrasonic transducer can also be dynamically adjusted according to the corresponding echo signals, so that the ultrasonic waves can be focused on the area of ​​interest as much as possible, and can penetrate the pollutants more accurately when necessary, so as to obtain target fingerprint data with relatively better results.

[0153] In some embodiments, the above-mentioned acquisition of target fingerprint data by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band can be further implemented by: controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band; 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.

[0154] 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.

[0155] In some embodiments, the target frequency band may include multiple sub-target frequency bands;

[0156] Accordingly, based on the target frequency band, the ultrasonic transducer is controlled to emit corresponding ultrasonic signals to acquire multiple sub-target fingerprint data; wherein, one sub-target fingerprint data corresponds to an ultrasonic signal of one sub-target frequency band.

[0157] Furthermore, multiple sub-target fingerprint data corresponding to different sub-target frequency bands can be used in combination to obtain target fingerprint data with relatively richer information and better results.

[0158] Specifically, for example, the high-frequency band (10-20MHz) can be divided into five sub-target frequency bands according to the corresponding frequency segmentation rules: 10-12MHz, 12-14MHz, 14-16MHz, 16-18MHz, and 18-20MHz. Then, the ultrasonic transducer is controlled to emit ultrasonic signals based on these five sub-target frequency bands, achieving multi-band scanning and obtaining five different echo signals. These five echo signals can each contain the different advantages and characteristics of the corresponding sub-target frequency band in fingerprint performance.

[0159] Furthermore, the five echo signals can be processed separately to obtain five corresponding sub-target fingerprint data; then, by combining the five sub-target fingerprint data, target fingerprint data that can simultaneously integrate the advantages of five different sub-target frequency bands can be obtained.

[0160] In some embodiments, after acquiring fingerprint data from multiple sub-targets, refer to Figure 4 As shown, in specific implementations, the method may also include the following:

[0161] S1: Extract the corresponding key features from the fingerprint data of multiple sub-targets respectively;

[0162] S2: Determine the reliability weight coefficient of key features according to the preset fusion rules;

[0163] S3: Based on the reliability weighting coefficient, multiple key features are fused in multiple frequency bands to obtain a target fingerprint image that meets the requirements; wherein, the target fingerprint image is used for fingerprint recognition.

[0164] In practice, the fingerprint features that each sub-target frequency band is good at representing can be determined by combining the advantages and characteristics of each sub-target frequency band with the line characteristics of different fingerprint features in the fingerprint data.

[0165] Correspondingly, the fingerprint features that the corresponding sub-target frequency bands are good at representing can be extracted from the fingerprint data of multiple sub-targets to obtain the corresponding key features.

[0166] For example, the basic outline of the deep structure can be extracted as key fingerprint features from the fingerprint data of sub-targets corresponding to the lower frequency sub-target bands; the surface fingerprint details can be extracted as key fingerprint features from the fingerprint data of sub-targets corresponding to the higher frequency sub-target bands; and the transitional features can be extracted as key fingerprint features from the fingerprint data of sub-targets corresponding to the medium frequency sub-target bands.

[0167] Furthermore, based on preset fusion rules, the reliability of each key feature in subsequent fingerprint data processing, such as fingerprint recognition, can be determined; based on the reliability level, the reliability weight coefficient of the key features can be determined; and then, based on the reliability weight coefficient, a target fingerprint image that meets the requirements can be obtained by multi-band weighted fusion of multiple key features.

[0168] Specifically, corresponding image processing algorithms (such as edge detection algorithms) can be used to integrate multiple key features in the same image to obtain a fused fingerprint image. Then, based on the reliability weight coefficient of each key feature, the display priority of each key feature in the image is set to obtain a target fingerprint image that meets the requirements.

[0169] The aforementioned target fingerprint image can be used for fingerprint recognition or for other related fingerprint data processing.

[0170] Before extracting the corresponding key features from multiple sub-target fingerprint data, the multiple sub-target fingerprint data can be aligned first. This is because the penetration depth of ultrasonic signals in different frequency bands is different, which may cause displacement or deformation between the obtained different sub-target fingerprint data.

[0171] Therefore, we can first perform affine transformation or non-rigid transformation on multiple sub-target fingerprint data to obtain multiple transformed sub-target fingerprint data, so as to ensure that the feature correspondence is consistent in different sub-target fingerprint data; and then perform subsequent data processing based on multiple transformed sub-target fingerprint data.

[0172] In some embodiments, after acquiring fingerprint data of multiple sub-targets, the method may further include the following:

[0173] S1: Using multiple sub-target fingerprint data, compare the fingerprint features with the corresponding user fingerprint feature templates of multiple frequency bands to obtain fingerprint feature comparison results of multiple frequency bands;

[0174] S2: Based on the contaminant information and / or humidity information of the finger, perform weighted calculations on the fingerprint feature comparison results of multiple frequency bands to obtain the target fingerprint feature comparison results;

[0175] S3: Determine whether the fingerprint recognition passes based on the target fingerprint feature comparison results.

[0176] Before implementation, when a user registers their fingerprint, the fingerprint recognition device can divide the entire frequency band (including high-frequency, mid-frequency, and low-frequency bands) into multiple sub-frequency bands (which can be referred to as multiple preset frequency bands) according to corresponding frequency segmentation rules. Then, it scans and acquires multiple fingerprint data based on each sub-frequency band. Based on these multiple fingerprint data, it constructs a user fingerprint feature template corresponding to the user across multiple frequency bands; each frequency band's user fingerprint feature template corresponds to one sub-frequency band. A correspondence is then established between the multiple frequency band user fingerprint feature templates and the user's identity information. Finally, the aforementioned multiple frequency band user fingerprint feature templates are stored in the user database to complete the user's fingerprint registration.

[0177] In practice, after collecting fingerprint data of multiple sub-targets, the user database can be queried according to the sub-target frequency bands corresponding to the fingerprint data of multiple sub-targets to determine the user fingerprint feature templates of multiple frequency bands corresponding to the sub-target frequency bands; then the sub-target fingerprint data is compared with the user fingerprint feature templates of the corresponding frequency bands to obtain the fingerprint feature comparison results of multiple frequency bands.

[0178] Furthermore, the reliability weighting coefficients of each sub-target frequency band can be determined based on pollutant information and / or humidity information; then, based on the reliability weighting coefficients of each sub-target frequency band, the fingerprint feature comparison results of multiple frequency bands are weighted to obtain the final target fingerprint feature comparison result.

[0179] Furthermore, based on the above target fingerprint feature comparison results, and taking into full account the specific environmental conditions of the current detection object, it is possible to accurately determine whether the fingerprint recognition has passed.

[0180] In some embodiments, the method may further include the following:

[0181] S1: According to the preset acquisition rules, control the ultrasonic transducer to emit ultrasonic signals of multiple preset frequency bands sequentially or in batches to acquire fingerprint data of multiple frequency bands.

[0182] S2: Based on fingerprint data from multiple frequency bands, construct and store user fingerprint feature templates for multiple frequency bands.

[0183] During the actual collection process, the collected fingerprint data can be stored in a folder corresponding to the preset frequency band; or, a frequency band label indicating the preset frequency band can be added to the collected fingerprint data.

[0184] In practice, user fingerprint feature templates for multiple frequency bands can be constructed and stored based on fingerprint data from multiple frequency bands, and these user fingerprint feature templates for multiple frequency bands can be stored simultaneously. Alternatively, user fingerprint feature templates for multiple frequency bands can be combined to construct a fingerprint fusion template that integrates user fingerprint feature targets from multiple frequency bands for later use.

[0185] In some embodiments, after acquiring information on contaminants and / or humidity of the fingers, the method may further include the following: based on the information on contaminants of the fingers, if it is determined that there are many contaminants on the fingers, a first prompt message about cleaning the fingers may be generated and triggered; and / or, based on the information on humidity of the fingers, if it is determined that the humidity of the fingers is high, a second prompt message about drying the fingers may be generated and triggered.

[0186] As can be seen from the above, the ultrasonic fingerprint data acquisition method provided in the embodiments of this specification can first acquire information on contaminants and / or humidity of the finger; then, based on the contaminant and / or humidity information, determine a matching target frequency band; and based on the target frequency band, control the ultrasonic transducer to emit corresponding ultrasonic signals to acquire target fingerprint data. This allows for the intelligent determination of a matching target frequency band based on the actual environmental conditions of the finger; and the acquisition of target fingerprint data by controlling the emission of corresponding ultrasonic signals based on this target frequency band. This effectively reduces errors caused by environmental factors such as contaminants and moisture in the finger environment, accurately obtaining high-quality fingerprint data containing one or more depth information that can be well applied to subsequent fingerprint data processing such as fingerprint recognition.

[0187] See Figure 5 As shown in the embodiments of this specification, another method for acquiring fingerprint data based on ultrasound is also provided. In specific implementation, this method may include the following:

[0188] S501: Controls the ultrasonic transducer to emit an initial ultrasonic signal and receive the corresponding initial echo signal;

[0189] S502: Determine the matching target frequency band based on the initial echo signal;

[0190] S503: Based on the target frequency band, the ultrasonic transducer is controlled to emit corresponding ultrasonic signals to acquire target fingerprint data.

[0191] The initial ultrasonic signal mentioned above can be a high-frequency ultrasonic signal.

[0192] Correspondingly, based on the initial echo signal, an initial fingerprint data (e.g., an initial fingerprint image) that focuses more on representing the surface fingerprint characteristics of the object being detected can be obtained; and then, based on the initial fingerprint data, it can be determined whether there are contaminants and / or moisture on the surface of the object being detected.

[0193] If there are no contaminants or moisture, the initial fingerprint data can be directly identified as the target fingerprint data that meets the requirements.

[0194] Conversely, if contaminants and / or moisture are present, contaminant and / or humidity information can be further obtained based on the initial echo signal; then, based on the contaminant and / or humidity information, a matching target frequency band can be determined; and based on the target frequency band, the ultrasonic transducer can be controlled to emit corresponding ultrasonic signals to obtain target fingerprint data that meets the requirements.

[0195] In some embodiments, the target frequency band may specifically include multiple sub-target frequency bands;

[0196] Accordingly, based on the target frequency band, the ultrasonic transducer is controlled to emit corresponding ultrasonic signals to acquire multiple sub-target fingerprint data; among them, one sub-target fingerprint data corresponds to an ultrasonic signal of one sub-target frequency band.

[0197] Furthermore, multiple sub-target fingerprint data can be combined to construct target fingerprint data that is more informative and has better performance.

[0198] This manual also provides another method for acquiring fingerprint data based on ultrasound, which may include the following in its implementation:

[0199] S1: Obtain contaminant information and / or humidity information on the fingerprint collection area;

[0200] S2: Determine the matching target frequency band based on the contaminant information and / or humidity information on the fingerprint collection area;

[0201] S3: Based on the target frequency band, the ultrasonic transducer is controlled to emit corresponding ultrasonic signals to acquire target fingerprint data.

[0202] In some embodiments, after acquiring contaminant information and / or humidity information on the fingerprint collection area, the method may further include: generating and sending a third prompt message about cleaning the fingerprint collection area when it is determined that there are many contaminants in the fingerprint collection area based on the contaminant information of the fingerprint collection area; and / or generating and sending a fourth prompt message about drying the fingerprint collection area when it is determined that the humidity of the fingerprint collection area is high based on the humidity information of the fingerprint collection area.

[0203] This manual also provides another method for acquiring fingerprint data based on ultrasound, which may include the following in its implementation:

[0204] S1: Based on the first frequency band, the first ultrasonic signal is emitted by controlling the ultrasonic transducer to obtain the first fingerprint data;

[0205] S2: Determine whether the first fingerprint data meets the preset processing requirements;

[0206] S3: If it is determined that the first fingerprint data does not meet the preset processing requirements, switch to the second frequency band and control the ultrasonic transducer to emit a second ultrasonic signal to obtain the second fingerprint data.

[0207] The first frequency band mentioned above can be a frequency band that focuses on collecting fingerprint features on the skin surface of the object being detected, such as a high-frequency band.

[0208] In practice, in one scenario, the clarity and completeness of the fingerprint features on the skin surface in the first fingerprint data can be detected to determine whether the first fingerprint data meets the preset processing requirements. If it is clear and complete, it is determined that it meets the preset processing requirements, and the first fingerprint data can be directly identified as the target fingerprint data.

[0209] If the clarity of the first fingerprint data is less than a preset clarity threshold, and / or the completeness is less than a preset completeness threshold, the first fingerprint data is determined not to meet the preset processing requirements. In this case, relevant contaminant information and / or humidity information can be acquired; and based on the contaminant information and / or humidity information, a matching second frequency band can be determined; then, by switching and according to the second frequency band, a second ultrasonic signal is emitted by controlling the ultrasonic transducer to acquire the second fingerprint data, which serves as the final target fingerprint data for subsequent fingerprint data processing.

[0210] In another scenario, the user database can be queried to obtain the first user fingerprint feature template corresponding to the first frequency band; and the first fingerprint data can be used to compare the fingerprint with the first user fingerprint feature template to obtain the first comparison result.

[0211] Based on the first comparison result, if fingerprint recognition passes, the relevant fingerprint data processing is completed. Conversely, if fingerprint recognition fails, the clarity and completeness of the first fingerprint data are checked. If the clarity of the first fingerprint data is less than a preset clarity threshold, and / or the completeness is less than a preset completeness threshold, the first fingerprint data is determined not to meet the preset processing requirements. At this point, a second ultrasonic signal can be emitted by controlling the ultrasonic transducer to acquire the second fingerprint data, based on the second frequency band. The frequency of the second frequency band is lower than that of the first frequency band.

[0212] Query the user database to obtain the second user fingerprint feature template corresponding to the second frequency band; and use the second fingerprint data to compare the fingerprint with the second user fingerprint feature template to obtain the second comparison result.

[0213] Based on the second comparison result, if fingerprint recognition passes, the relevant fingerprint data processing is completed. Conversely, if fingerprint recognition fails, the clarity and completeness of the second fingerprint data are checked. If the clarity of the second fingerprint data is less than a preset clarity threshold, and / or the completeness is less than a preset completeness threshold, the second fingerprint data is determined not to meet the preset processing requirements. At this point, a third ultrasonic signal can be emitted by controlling the ultrasonic transducer to acquire the third fingerprint data, based on the third frequency band. The frequency of the third frequency band is lower than that of the second frequency band.

[0214] This process continues until fingerprint recognition is successful, or no further ultrasonic signals are available to switch to.

[0215] 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.

[0216] Specifically, the network communication port 601 can be used to acquire information about contaminants and / or humidity on the fingers.

[0217] The processor 602 can be used to determine a matching target frequency band based on the contaminant information and / or humidity information of the finger; and to acquire target fingerprint data by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band.

[0218] The memory 603 can be used to store the corresponding instruction program and related intermediate data.

[0219] 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 data processing based on ultrasonic fingerprint data acquisition.

[0220] 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.

[0221] 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.

[0222] 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.

[0223] This specification also provides a computer-readable storage medium based on the above-described ultrasonic fingerprint data acquisition method. The computer-readable storage medium stores computer program instructions that, when executed, perform the following: acquire contaminant information and / or humidity information of the finger; determine a matching target frequency band based on the contaminant information and / or humidity information of the finger; and acquire target fingerprint data by controlling an ultrasonic transducer to emit a corresponding ultrasonic signal according to the target frequency band.

[0224] 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.

[0225] 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.

[0226] This specification also provides a computer program product, which includes at least a computer program. When the computer program is executed by a processor, it performs the following method steps: acquiring contaminant information and / or humidity information of a finger; determining a matching target frequency band based on the contaminant information and / or humidity information of the finger; and acquiring target fingerprint data by controlling an ultrasonic transducer to emit a corresponding ultrasonic signal based on the target frequency band.

[0227] See Figure 7 As shown in the embodiments of this specification, an ultrasonic fingerprint data acquisition device is also provided, which may specifically include the following structural modules:

[0228] The first acquisition module 701 can be used to acquire information about contaminants and / or humidity on the fingers;

[0229] The determination module 702 can be used to determine the matching target frequency band based on the contaminant information and / or humidity information of the finger;

[0230] The second acquisition module 703 can be used to acquire target fingerprint data by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band.

[0231] In some embodiments, when the first acquisition module 701 is specifically implemented, it can acquire the contaminant information and / or humidity information of the finger in the following manner: control the ultrasonic transducer to emit an initial ultrasonic signal and receive the corresponding initial echo signal; acquire the contaminant information and / or humidity information of the finger based on the initial echo signal.

[0232] In some embodiments, the device may also be used to: collect current environmental information; determine a matching initial frequency band based on the current environmental information; and determine an initial ultrasonic signal based on the initial frequency band.

[0233] In some embodiments, when the device is specifically implemented, it can obtain the contaminant information of the finger based on the initial echo signal in the following manner: determining the signal strength and / or signal-to-noise ratio of the initial echo signal; determining whether the finger is contaminated based on the signal strength and / or signal-to-noise ratio of the initial echo signal; if it is determined that the finger is contaminated, calculating the attenuation value of the signal strength and / or the decrease value of the signal-to-noise ratio of the initial echo signal; and determining the contaminant information by querying a preset contaminant mapping table based on the attenuation value of the signal strength and / or the decrease value of the signal-to-noise ratio.

[0234] In some embodiments, the pollutant information may specifically include at least one of the following: pollutant type, pollutant thickness, pollutant area, pollutant location, etc.

[0235] In some embodiments, when the determination module 702 is specifically implemented, it can determine the matching target frequency band based on the contaminant information of the finger in the following manner: based on the contaminant information of the finger, the matching target frequency band is determined by querying a preset contaminant frequency band matching rule set.

[0236] In some embodiments, the device may also be used to: determine a matching target signal intensity based on contaminant information and / or humidity information of the finger; and acquire target fingerprint data by controlling an ultrasonic transducer to emit a corresponding ultrasonic signal based on the target signal intensity.

[0237] In some embodiments, the target frequency band may specifically include multiple sub-target frequency bands;

[0238] Accordingly, in specific implementation, the device can acquire multiple sub-target fingerprint data by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band; wherein, one sub-target fingerprint data corresponds to an ultrasonic signal of one sub-target frequency band.

[0239] In some embodiments, after acquiring multiple sub-target fingerprint data, the device may further be used to: extract corresponding key features from the multiple sub-target fingerprint data respectively; determine the reliability weight coefficient of the key features according to a preset fusion rule; perform multi-band fusion on the multiple key features according to the reliability weight coefficient to obtain a target fingerprint image that meets the requirements; wherein the target fingerprint image is used for fingerprint recognition.

[0240] In some embodiments, after acquiring multiple sub-target fingerprint data, the device may further be used to: compare the fingerprint features of the multiple sub-target fingerprint data with the corresponding user fingerprint feature templates of multiple frequency bands to obtain fingerprint feature comparison results of multiple frequency bands; perform weighted calculations on the fingerprint feature comparison results of multiple frequency bands based on the contaminant information and / or humidity information of the finger to obtain the target fingerprint feature comparison result; and determine whether fingerprint recognition is successful based on the target fingerprint feature comparison result.

[0241] In some embodiments, the device can also be used to: control an ultrasonic transducer to sequentially or in stages emit ultrasonic signals of multiple preset frequency bands according to preset acquisition rules, and acquire fingerprint data of multiple frequency bands; and construct and store user fingerprint feature templates of multiple frequency bands based on the fingerprint data of multiple frequency bands.

[0242] This specification also provides another ultrasonic-based fingerprint data acquisition device, which may specifically include:

[0243] The control module is used to control the ultrasonic transducer to emit the initial ultrasonic signal and receive the corresponding initial echo signal.

[0244] The determination module is used to determine the matching target frequency band based on the initial echo signal;

[0245] The acquisition module is used to acquire target fingerprint data by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band.

[0246] In some embodiments, the target frequency band includes multiple sub-target frequency bands;

[0247] Accordingly, when the above-mentioned device is implemented, it can acquire multiple sub-target fingerprint data by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band; wherein, one sub-target fingerprint data corresponds to an ultrasonic signal of one sub-target frequency band.

[0248] 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 the 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 devices or units shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0249] As can be seen from the above, the ultrasonic fingerprint data acquisition device provided in the embodiments of this specification can effectively reduce the error interference caused by environmental factors such as pollutants and moisture in the finger environment, accurately obtain fingerprint data containing one or more depth information, and can be well applied to subsequent fingerprint data processing such as fingerprint recognition, resulting in high-quality fingerprint data.

[0250] In a specific scenario example, the ultrasonic fingerprint data acquisition method provided in this manual can be used to achieve fingerprint scanning unlocking. For details on the implementation process, please refer to the following content.

[0251] In this scenario example, existing methods use a single-frequency ultrasonic signal for scanning, which has limited penetration capability at different depths and cannot capture all fingerprint details, especially when the surface is dirty (e.g., contaminants) or moist (e.g., water vapor). Relying solely on a single frequency band for verification during the unlocking phase is susceptible to changes in environmental and surface conditions, reducing unlocking security.

[0252] To address the aforementioned issues and their root causes, this scenario example considers dynamically adjusting the transmission frequency and using multi-band scanning to capture fingerprint information at different depths and with varying characteristics. This reduces interference from surface contaminants and improves recognition accuracy and security. First, multiple frequency bands of ultrasonic signals are used for scanning during the fingerprint detection stage. Different frequency bands can penetrate different depths of the finger surface, capturing more detailed features. Multi-band signals cover more fingerprint features, reducing interference from surface contaminants (such as dirt and grease). Second, the transmission frequency and intensity of the ultrasonic waves are dynamically adjusted based on the real-time detected signal quality. High-frequency signals are used to capture surface details, while low-frequency signals penetrate deeper layers of dirt. Dynamic frequency adjustment ensures optimal signal quality under different surface conditions. Third, the scanning results from different frequency bands are fused, and an image processing algorithm is used to generate a high-resolution fingerprint image by integrating the multi-band data. Combining the advantages of multi-band scanning provides a more comprehensive and detailed fingerprint image, improving recognition accuracy and reliability. Furthermore, multi-band verification during fingerprint enrollment and unlocking significantly enhances unlocking security. The fingerprint registration process records multi-band features, and these features are rescanned and verified during the unlocking process to ensure the accuracy and security of fingerprint matching.

[0253] Specifically, the process includes the following parts: Initialization: During the fingerprint enrollment phase, the system initializes multiple ultrasonic transducers (or ultrasonic transducers) and configures them to operate at different frequency bands. This ensures that scanning can be performed at different frequency bands to acquire multi-layered fingerprint features (e.g., target fingerprint data) on the surface and inside the finger. Multi-band scanning: The multi-band scanning mode is activated, and the ultrasonic transducers sequentially emit ultrasonic signals at different frequency bands. Each frequency band's signal penetrates to different depths on the finger surface, capturing more detailed features. By covering more fingerprint features with signals from different frequency bands, the depth and detail of the fingerprint image are improved, and interference from surface contaminants (such as dirt and grease) is reduced. Data acquisition: The ultrasonic transducers receive reflected signals and record the scan data for each frequency band. The acquisition of multi-band data provides comprehensive fingerprint information, improving image clarity and resolution.

[0254] In practice, the frequency bands that can be used typically cover high frequency (10-20MHz) (e.g., high-frequency band) and low frequency (1-5MHz) (e.g., low-frequency band). High-frequency ultrasound can capture surface details but has poor penetration, making it suitable for treating relatively clean surfaces; low-frequency ultrasound has strong penetration, able to penetrate dirt and grease, but has lower resolution, thus suitable for dirtier surfaces. Using these two frequency bands in combination can reduce interference from surface contaminants.

[0255] Specifically, it can be divided into three frequency bands: high frequency, low frequency, and mid frequency.

[0256] The low-frequency band (1-5MHz) has the following function: Low-frequency ultrasound has strong penetrating power, enabling it to penetrate surface contaminants such as dirt and grease, and can reach deeper layers of the skin on the fingers. Although its resolution is lower, it can capture deeper fingerprint features, such as prominent ridges and their overall shape. Extractable features include prominent ridges, valleys, and the outline of deep fingerprint structures, which can still be clearly recorded even when the surface is contaminated.

[0257] Mid-frequency band (5-10MHz): Mid-frequency ultrasound strikes a balance between resolution and penetration. It can penetrate surface dirt while capturing more detailed surface fingerprint features. Extractable features include: medium-detail fingerprint features such as mid-layer ridges, fingerprint lines, and some fine details. These features fill the gap between low-frequency and high-frequency bands, connecting the deeper and surface layers.

[0258] High-frequency band (10-20MHz): While high-frequency ultrasound has weaker penetrating power, it offers high resolution, clearly capturing surface details. It is suitable for clean or relatively clean surfaces. Extractable features: Surface detail features such as fine ridges, pores, and fine details of fingerprints. These details are crucial for fingerprint uniqueness but can be interfered with by surface contamination.

[0259] In practice, the ultrasonic frequency can be dynamically adjusted in the following way:

[0260] a) Real-time signal quality monitoring: During the scanning process, the system monitors the quality of the ultrasonic signal in real time, including parameters such as signal-to-noise ratio and reflection intensity. This ensures dynamic adjustments can be made based on the real-time signal quality to optimize the scanning effect.

[0261] b) Dynamic adjustment of transmission frequency and intensity: Based on real-time monitoring data, the system dynamically adjusts the transmission frequency and intensity of the ultrasonic waves. When a large amount of surface contamination is detected, the system can increase the transmission intensity or switch to a higher frequency to improve signal penetration. Through dynamic adjustment of frequency and intensity, the system adapts to different surface conditions, ensuring optimal signal quality in complex environments.

[0262] In practice, the system can determine the scanning quality by monitoring the signal-to-noise ratio and intensity of the reflected signal. If the signal-to-noise ratio of the reflected signal decreases or the intensity weakens, it may indicate the presence of dirt or other interfering substances on the fingerprint surface. In this case, the system will consider the scanning conditions unsatisfactory and require dynamic adjustment of the transmission parameters.

[0263] Specific adjustments may include: adjustments to the transmission intensity and major adjustments to the transmission frequency.

[0264] The adjustment of the aforementioned emission intensity can include the following: If the system detects a decrease in the quality of the reflected signal, the penetration of the signal can be improved by increasing the intensity of the ultrasonic emission. Specifically, this is achieved by increasing the output voltage or power of the drive module, thereby increasing the intensity of the emitted signal. The amount of increase in emission intensity can be dynamically adjusted based on signal quality; for example, the greater the decrease in signal-to-noise ratio, the greater the increase in emission intensity. The adjustment of the aforementioned emission frequency can also include the following: The system can also switch to a more suitable frequency band based on the detected signal conditions. For example, when a large amount of surface dirt is detected, the system may switch to a lower frequency (e.g., 3MHz) to enhance penetration. Conversely, if it is necessary to capture surface details, a higher frequency (e.g., 15MHz) is used.

[0265] In practical implementation, for multi-band acquired data, frequency band labeling and data separation can be performed: the system can label the scan data for each frequency band. During data acquisition, ultrasonic signals emitted at different frequency bands are recorded separately, each with its own identification information. Data for each frequency band can be stored in a separate data structure for easier subsequent processing. For example, scan data for the 1-5MHz band can be stored in one folder or database entry, while data for the 10-20MHz band can be stored in another folder. A mapping table can also be used to manage scan data for different frequency bands. During scanning, the system records the corresponding depth and characteristics of different frequency bands using a table. For example, low frequencies (1-5MHz) are responsible for recording the deeper ridge information of the finger, while high frequencies (10-20MHz) record the surface detail information. Through this mapping table, the system can quickly locate and extract the scan data corresponding to a specific frequency band after scanning for further processing. Time-slicing recording can also be used to manage data from different frequency bands. If the system switches between different frequency bands in chronological order for scanning, it can record the time point of each transmission band switch and classify the received reflected signals within the corresponding time period into the appropriate frequency band. For example, the first 1 millisecond corresponds to the high-frequency band, and the next 1 millisecond corresponds to the low-frequency band. This time-slicing-based recording method ensures that data from different frequency bands is distinguished and can be traced back to a specific frequency band.

[0266] For example, when using high-frequency (15MHz) and low-frequency (3MHz) ultrasound for scanning, the system first sends a high-frequency signal and records the high-frequency data, and then sends a low-frequency signal and records the low-frequency data. Each set of data is labeled with frequency information (e.g., 15MHz or 3MHz). The system stores the scan data at different frequencies in different locations using frequency band labels, or maps this data to fingerprint image layers of different depths using a mapping table.

[0267] In practice, multi-band data can also be fused. This can include the following:

[0268] a) Data Fusion: Data obtained from scanning different frequency bands is fused. Image processing algorithms are used to integrate fingerprint features from low-frequency, mid-frequency, and high-frequency bands into a single composite fingerprint image. Through the fusion of multi-frequency band data, a high-resolution fingerprint image is generated, providing more comprehensive and detailed fingerprint information.

[0269] b) Feature Extraction and Image Optimization: Key fingerprint feature points, such as ridges, valleys, and minutiae, are extracted from the fused image. Denoising and enhancement image processing techniques are used to optimize the fused fingerprint image and improve image quality. Image optimization enhances detail representation, ensuring accurate extraction and recognition of fingerprint features.

[0270] In practice, during multi-band fingerprint scanning, signals from different frequency bands capture fingerprint features of varying depths and resolutions. To obtain a comprehensive and high-resolution fingerprint image, the system can fuse the scanning results from these different frequency bands. The specific fusion steps are as follows:

[0271] Image alignment is the first step in aligning fingerprint images from different frequency bands. Since signals from different frequency bands have varying penetration depths, displacement or deformation may occur. Image registration algorithms (such as affine transformation or non-rigid transformation) are used to align these images, ensuring that feature points across all frequency bands correspond consistently.

[0272] The weighted average method fuses images from different frequency bands using a weighted average approach. Typically, low-frequency images are used to provide the basic contours of deep structures, while high-frequency images provide fine surface features. Mid-frequency images serve as an intermediate layer. Data from each frequency band is assigned different weights based on its reliability; for example, detail components from high-frequency images may be given higher weights, while low-frequency images are used more for supplementing deep contours.

[0273] Feature extraction and fusion are performed to extract key fingerprint feature points, such as ridges, valleys, and minutiae, from the fused image. Image processing algorithms (such as edge detection and feature extraction algorithms) are used to extract corresponding features from images of different frequency bands and integrate them into the fused image. For example, high-frequency detailed features are preferentially displayed in the final image, while the coarse contours of low-frequency bands are used as supplementary features.

[0274] In practice, during the unlocking phase, the system restarts multi-band ultrasonic scanning, using the same frequency band as the registration phase for fingerprint scanning. This ensures that the scanning during the unlocking phase is consistent with the registration phase, improving the consistency and accuracy of recognition.

[0275] During the unlocking process, real-time comparison and dynamic adjustments are possible: the multi-band fingerprint data obtained from real-time scanning is compared with the pre-recorded multi-band fingerprint template. Based on the signal quality detected in real time, the transmission frequency and intensity are dynamically optimized to reduce interference from surface contaminants (such as dirt and grease). Through multi-band verification and dynamic adjustments, the security and accuracy of the unlocking stage are improved, ensuring that only genuine and complete fingerprints can unlock the device.

[0276] In practice, the system can match the fingerprint data of each frequency band with the fingerprint template generated for that frequency band during the data entry process. The specific steps are as follows:

[0277] a) Multi-band scanning: The system still uses multiple frequency bands (such as low frequency band, mid frequency band and high frequency band) to scan the finger in sequence to obtain fingerprint images under different frequency bands.

[0278] b) Template creation during the fingerprint enrollment phase: When enrolling fingerprints, the system creates a separate fingerprint template for each frequency band. For example, the template for the low-frequency band records deeper ridges and valleys, the template for the mid-frequency band records mid-level features, and the template for the high-frequency band records surface details.

[0279] For example, the system first uses a low-frequency band (3MHz) to scan and capture deep, prominent ridges in the fingerprint. This band's data can penetrate surface dirt or moisture. The mid-frequency band (10MHz) is used to capture mid-layer features of the fingerprint, primarily including detailed features and some mid-layer valleys and ridges. The high-frequency band (20MHz) is used to capture surface details of the fingerprint, such as pores and subtle variations in the fingerprint pattern. This band is suitable for clean surfaces and provides high-resolution surface images. The comparison results for each band are output separately and stored in the system's verification buffer.

[0280] c) Comparison during the unlocking phase: During unlocking, the system sequentially or in stages acquires fingerprint images for each frequency band and compares them with the templates for the corresponding frequency bands from the registration phase. The comparison process is independent of other frequency bands, meaning that the comparison result for each frequency band is based on its own characteristics, rather than relying on the fusion of multi-frequency band data.

[0281] Through the above scenario examples, the system uses integrated environmental sensors to detect dirt, humidity, or temperature on the fingerprint surface in real time, and dynamically selects the optimal scanning frequency band based on the detected conditions. For example, when a lot of dirt is detected on the fingerprint surface, the system prioritizes scanning the low-frequency band to enhance the penetration of ultrasonic waves; when the surface is clean, it prioritizes the high-frequency band to capture details. After independently verifying each frequency band, the system uses a weighted algorithm to comprehensively evaluate the results. Based on the contribution of different frequency bands to the unlocking process, the system assigns different weights to each band. For example, on a clean fingerprint surface, the system assigns higher weight to the verification results of the high-frequency band to ensure that more surface details are captured. On a dirtier surface, the system assigns higher weight to the verification results of the low-frequency band to utilize its stronger penetration. Through weighted evaluation, the system can flexibly adjust the comparison priority of each frequency band according to different environmental conditions, reducing misjudgments caused by failure of a single frequency band.

[0282] This allows for the capture of more fingerprint features through multi-band scanning, improving image quality. Dynamic frequency adjustment and adaptive filtering techniques enhance the system's adaptability to dirty fingers and complex surface conditions. Optimal detection results are ensured by real-time adjustment of the transmission frequency and signal processing parameters. Multi-band verification during fingerprint enrollment and unlocking significantly improves unlocking security.

[0283] 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.

[0284] 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.

[0285] 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.

[0286] 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.

[0287] 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.

[0288] 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 acquiring fingerprint data based on ultrasound, characterized in that, include: Acquire information on contaminants and / or humidity of the fingers; including: collecting current environmental information; determining a matching initial frequency band based on the current environmental information; determining an initial ultrasonic signal based on the initial frequency band; controlling the ultrasonic transducer to emit the initial ultrasonic signal and receiving the corresponding initial echo signal; and acquiring information on contaminants and / or humidity of the fingers based on the initial echo signal. Based on the contaminant information and / or humidity information of the fingers, determine the matching target frequency band; Based on the target frequency band, the target fingerprint data is obtained by controlling the ultrasonic transducer to emit corresponding ultrasonic signals.

2. The method according to claim 1, characterized in that, Based on the initial echo signal, information about contaminants on the finger is obtained, including: Determine the signal strength and / or signal-to-noise ratio of the initial echo signal based on the initial echo signal; Determine whether there is contaminant on the finger based on the signal strength and / or signal-to-noise ratio of the initial echo signal; If contaminants are confirmed on the finger, calculate the attenuation of the signal strength of the initial echo signal and / or the decrease in the signal-to-noise ratio. Based on the signal strength attenuation and / or the decrease in signal-to-noise ratio, pollutant information is determined by querying a preset pollutant mapping table.

3. The method according to claim 2, characterized in that, The pollutant information includes at least one of the following: pollutant type, pollutant thickness, pollutant area, and pollution location.

4. The method according to claim 2, characterized in that, Based on the contaminant information from the fingers, matching target frequency bands are determined, including: Based on the contaminant information on the finger, the target frequency band that matches is determined by querying a preset set of contaminant frequency band matching rules.

5. The method according to claim 1, characterized in that, The method further includes: Based on the contaminant information and / or humidity information of the fingers, determine the matching target signal intensity; Based on the target signal strength, the target fingerprint data is obtained by controlling the ultrasonic transducer to emit corresponding ultrasonic signals.

6. The method according to claim 1, characterized in that, The target frequency band includes multiple sub-target frequency bands; Accordingly, based on the target frequency band, the ultrasonic transducer is controlled to emit corresponding ultrasonic signals to acquire multiple sub-target fingerprint data; among them, one sub-target fingerprint data corresponds to an ultrasonic signal of one sub-target frequency band.

7. The method according to claim 6, characterized in that, After acquiring fingerprint data from multiple sub-targets, the method further includes: Key features were extracted from the fingerprint data of multiple sub-targets. Based on the preset fusion rules, the reliability weight coefficients of key features are determined; Based on the reliability weighting coefficient, multiple key features are fused in multiple frequency bands to obtain a target fingerprint image that meets the requirements; wherein, the target fingerprint image is used for fingerprint recognition.

8. The method according to claim 6, characterized in that, After acquiring fingerprint data from multiple sub-targets, the method further includes: Using multiple sub-target fingerprint data, fingerprint features are compared with corresponding user fingerprint feature templates in multiple frequency bands to obtain fingerprint feature comparison results for multiple frequency bands; Based on the contaminant information and / or humidity information of the fingers, the fingerprint feature comparison results of multiple frequency bands are weighted and calculated to obtain the target fingerprint feature comparison result; Based on the comparison results of the target fingerprint features, determine whether the fingerprint recognition is successful.

9. The method according to claim 8, characterized in that, The method further includes: According to the preset acquisition rules, the ultrasonic transducer is controlled to emit ultrasonic signals of multiple preset frequency bands sequentially or in multiple batches to acquire fingerprint data of multiple frequency bands. Based on fingerprint data from multiple frequency bands, construct and store user fingerprint feature templates for multiple frequency bands.

10. A method for acquiring fingerprint data based on ultrasound, characterized in that, include: The ultrasonic transducer is controlled to emit an initial ultrasonic signal and receive a corresponding initial echo signal; wherein the initial ultrasonic signal is used to detect whether the user is currently pressing the fingerprint collection area; and, when it is determined that the user is currently pressing the fingerprint collection area, relevant contaminant information and / or humidity information are acquired. Based on the initial echo signal, the matching target frequency band is determined; Based on the target frequency band, the target fingerprint data is obtained by controlling the ultrasonic transducer to emit corresponding ultrasonic signals.

11. The method according to claim 10, characterized in that, The target frequency band includes multiple sub-target frequency bands; Accordingly, based on the target frequency band, the ultrasonic transducer is controlled to emit corresponding ultrasonic signals to acquire multiple sub-target fingerprint data; among them, one sub-target fingerprint data corresponds to an ultrasonic signal of one sub-target frequency band.

12. A method for acquiring fingerprint data based on ultrasound, characterized in that, include: Acquire contaminant information and / or humidity information on the fingerprint collection area; including: collecting current environmental information; determining a matching initial frequency band based on the current environmental information; determining an initial ultrasonic signal based on the initial frequency band; controlling the ultrasonic transducer to emit the initial ultrasonic signal and receiving the corresponding initial echo signal; acquiring contaminant information and / or humidity information of the finger based on the initial echo signal; Based on the contaminant information and / or humidity information on the fingerprint collection area, the matching target frequency band is determined; Based on the target frequency band, the target fingerprint data is obtained by controlling the ultrasonic transducer to emit corresponding ultrasonic signals.

13. A method for acquiring fingerprint data based on ultrasound, characterized in that, include: Based on the first frequency band, the first ultrasonic signal is emitted by controlling the ultrasonic transducer to obtain the first fingerprint data; Determine whether the first fingerprint data meets the preset processing requirements; If the first fingerprint data does not meet the preset processing requirements, the system switches to the second frequency band and controls the ultrasonic transducer to emit a second ultrasonic signal to acquire the second fingerprint data. The method further includes: when the first fingerprint data does not meet the preset processing requirements, collecting the current environmental information; and determining the matching initial frequency band based on the current environmental information. Based on the initial frequency band, the initial ultrasonic signal is determined; the ultrasonic transducer is controlled to emit the initial ultrasonic signal and receive the corresponding initial echo signal; based on the initial echo signal, information on contaminants and / or humidity of the finger is obtained; based on the contaminant information and / or humidity information, a matching second frequency band is determined.

14. A fingerprint data acquisition device based on ultrasound, characterized in that, include: The first acquisition module is used to acquire information about contaminants and / or humidity on the fingers; The determination module is used to determine the matching target frequency band based on the contaminant information and / or humidity information of the finger; The second acquisition module is used to acquire target fingerprint data by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band. The first acquisition module is specifically used for: collecting current environmental information; determining a matching initial frequency band based on the current environmental information; determining an initial ultrasonic signal based on the initial frequency band; controlling the ultrasonic transducer to emit the initial ultrasonic signal and receiving the corresponding initial echo signal; and acquiring contaminant information and / or humidity information of the finger based on the initial echo signal.

15. 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 13.

16. 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 13.

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