Fingerprint data acquisition method and device based on ultrasonic waves and electronic equipment

Abstract

The invention provides a fingerprint data acquisition method and device based on ultrasonic waves and electronic equipment, and can be applied to the technical field of fingerprint identification. Based on the method, during specific implementation, pollutant information and / or humidity information of a finger can be firstly obtained; determining a matched target frequency band according to the pollutant information and / or humidity information of the finger; and according to the target frequency band, controlling an ultrasonic transducer to emit a corresponding ultrasonic signal to obtain target fingerprint data. The matched target frequency band is intelligently determined through analysis and according to the actual environment condition of the finger; and based on the target frequency band, target fingerprint data are acquired by controlling to transmit corresponding ultrasonic signals, so that error interference caused by environmental factors such as finger pollutants and moisture can be effectively reduced, and one or more pieces of depth information can be accurately acquired. The method can be well applied to subsequent fingerprint data processing such as fingerprint identification.

Description

Technical Field

[0001] This specification belongs to the technical field of fingerprint recognition, and particularly relates to a method, apparatus, and electronic device for obtaining fingerprint data based on ultrasonic waves. Background Art

[0002] Based on existing fingerprint data acquisition methods, most do not make distinctions and directly use a unified method to collect fingerprint data for subsequent fingerprint data processing such as fingerprint recognition. However, the environmental conditions when collecting fingerprint data in different scenarios often vary greatly, resulting in a large uncertainty in the data quality of the fingerprint data collected based on the above method, thereby affecting subsequent fingerprint data processing.

[0003] Regarding the above problems, no effective solution has been proposed yet. Summary of the Invention

[0004] This specification provides a method, apparatus, and electronic device for obtaining fingerprint data based on ultrasonic waves, which can effectively reduce the error interference caused by environmental factors such as finger contaminants and moisture when collecting fingerprint data, and collect fingerprint data with higher quality.

[0005] This specification provides a method for obtaining fingerprint data based on ultrasonic waves, including:

[0006] Obtain contaminant information and / or humidity information of the finger;

[0007] Determine a matching target frequency band according to the contaminant information and / or humidity information of the finger;

[0008] According to the target frequency band, control the ultrasonic transducer to emit a corresponding ultrasonic wave signal to obtain target fingerprint data.

[0009] In one embodiment, obtaining contaminant information and / or humidity information of the finger includes:

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

[0011] Obtain contaminant information and / or humidity information of the finger according to the initial echo signal.

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

[0013] Collect current environmental information;

[0014] Determine a matching initial frequency band according to the current environmental information;

[0015] Determine an initial ultrasonic wave signal according to the initial frequency band.

[0016] In one embodiment, according to the initial echo signal, pollutant information of the finger is obtained, including:

[0017] According to the initial echo signal, determine the signal intensity and / or signal-to-noise ratio of the initial echo signal;

[0018] According to the signal intensity and / or signal-to-noise ratio of the initial echo signal, determine whether there is a pollutant on the finger;

[0019] When it is determined that there is a pollutant on the finger, calculate the attenuation value of the signal intensity of the initial echo signal and / or the decrease value of the signal-to-noise ratio;

[0020] According to the attenuation value of the signal intensity and / or the decrease value of the signal-to-noise ratio, by querying a preset pollutant mapping relation table, determine the pollutant information.

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

[0022] In one embodiment, according to the pollutant information of the finger, determine a matching target frequency band, including:

[0023] According to the pollutant information of the finger, by querying a preset pollutant frequency band matching rule set, determine a matching target frequency band.

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

[0025] According to the pollutant information and / or humidity information of the finger, determine a matching target signal intensity;

[0026] According to the target signal intensity, by controlling the ultrasonic transducer to emit a corresponding ultrasonic signal, obtain target fingerprint data.

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

[0028] Correspondingly, according to the target frequency band, by controlling the ultrasonic transducer to emit a corresponding ultrasonic signal, obtain a plurality of sub-target fingerprint data; wherein, one sub-target fingerprint data corresponds to an ultrasonic signal of one sub-target frequency band.

[0029] In one embodiment, after obtaining a plurality of sub-target fingerprint data, the method further includes:

[0030] Extract corresponding key features from the plurality of sub-target fingerprint data respectively;

[0031] According to a preset fusion rule, determine the reliability weight coefficient of the key features;

[0032] Fuse multiple key features in multiple frequency bands 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.

[0033] In one embodiment, after obtaining multiple sub-target fingerprint data, the method further includes:

[0034] Use the multiple sub-target fingerprint data to perform fingerprint feature comparison with the user fingerprint feature templates in multiple corresponding frequency bands respectively to obtain fingerprint feature comparison results in multiple frequency bands;

[0035] Perform weighted operation on the fingerprint feature comparison results in multiple frequency bands according to the pollutant information and / or humidity information of the finger to obtain a target fingerprint feature comparison result;

[0036] Determine whether the fingerprint recognition passes according to the target fingerprint feature comparison result.

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

[0038] Control the ultrasonic transducer to sequentially or separately emit ultrasonic signals in multiple preset frequency bands according to the preset acquisition rule, and collect fingerprint data in multiple frequency bands;

[0039] Construct and store user fingerprint feature templates in multiple frequency bands according to the fingerprint data in multiple frequency bands.

[0040] This specification also provides a method for obtaining fingerprint data based on ultrasonic waves, including:

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

[0042] Determine the matching target frequency band according to the initial echo signal;

[0043] According to the target frequency band, control the ultrasonic transducer to emit corresponding ultrasonic signals to obtain target fingerprint data.

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

[0045] Correspondingly, according to the target frequency band, control the ultrasonic transducer to emit corresponding ultrasonic signals to obtain multiple sub-target fingerprint data; wherein, one sub-target fingerprint data corresponds to the ultrasonic signal of one sub-target frequency band.

[0046] This specification also provides a method for obtaining fingerprint data based on ultrasonic waves, including:

[0047] Obtain the pollutant information and / or humidity information on the fingerprint acquisition area;

[0048] Determine a matching target frequency band according to the pollutant information and / or humidity information on the fingerprint acquisition area;

[0049] According to the target frequency band, control the ultrasonic transducer to emit corresponding ultrasonic signals to obtain target fingerprint data.

[0050] This specification also provides a method for obtaining fingerprint data based on ultrasonic waves, including:

[0051] According to the first frequency band, control the ultrasonic transducer to emit the first ultrasonic signal to obtain the first fingerprint data;

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

[0053] In the case where it is determined that the first fingerprint data does not meet the preset processing requirements, switch and according to the second frequency band, control the ultrasonic transducer to emit the second ultrasonic signal to obtain the second fingerprint data.

[0054] This specification also provides a device for obtaining fingerprint data based on ultrasonic waves, including:

[0055] A first acquisition module for acquiring the pollutant information and / or humidity information of the finger;

[0056] A determination module for determining a matching target frequency band according to the pollutant information and / or humidity information of the finger;

[0057] A second acquisition module for controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band to obtain target fingerprint data.

[0058] This specification also provides an electronic device, including a processor and a memory for storing processor-executable instructions, and when the processor executes the instructions, the steps of the method for obtaining fingerprint data based on ultrasonic waves are implemented.

[0059] This specification also provides a computer-readable storage medium, on which computer instructions are stored, and when the instructions are executed by a processor, the steps of the method for obtaining fingerprint data based on ultrasonic waves are implemented.

[0060] Based on the ultrasonic-based fingerprint data acquisition method, device, and electronic device provided in this specification, in specific implementation, the pollutant information and / or humidity information of the finger can be obtained first; then, according to the pollutant information and / or humidity information of the finger, the matching target frequency band can be determined; according to the target frequency band, the ultrasonic transducer can be controlled to emit corresponding ultrasonic signals to obtain the target fingerprint data. By analyzing and according to the actual environmental conditions of the finger, different situations are distinguished, and the matching target frequency band is intelligently determined; then, based on this target frequency band, the target fingerprint data is obtained by controlling the emission of corresponding ultrasonic signals, so as to effectively reduce the error interference caused by environmental factors such as finger pollutants and moisture during fingerprint data acquisition, and accurately acquire fingerprint data containing one or more depth information, which can be better applied to subsequent fingerprint data processing such as fingerprint recognition. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] To more clearly illustrate the embodiments of this specification, the drawings required for use in the embodiments will be briefly introduced below. The drawings in the following description are only some embodiments recorded in this specification. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0062] Figure 1 is a schematic flowchart of an ultrasonic-based fingerprint data acquisition method provided by an embodiment of this specification;

[0063] Figure 2 is a schematic diagram of an embodiment of applying the ultrasonic-based fingerprint data acquisition method provided by an embodiment of this specification in a scenario example;

[0064] Figure 3 is a schematic diagram of an embodiment of applying the ultrasonic-based fingerprint data acquisition method provided by an embodiment of this specification in a scenario example;

[0065] Figure 4 is a schematic diagram of an embodiment of applying the ultrasonic-based fingerprint data acquisition method provided by an embodiment of this specification in a scenario example;

[0066] Figure 5 is a schematic flowchart of an ultrasonic-based fingerprint data acquisition method provided by another embodiment of this specification;

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

[0068] Figure 7 is a schematic diagram of the structural composition of an ultrasonic-based fingerprint data acquisition device provided by an embodiment of this specification. Detailed implementation manners

[0069] In order 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 in conjunction with the accompanying drawings in the embodiments of this specification. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. Based on the embodiments in this specification, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope 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 users or fully authorized by relevant parties. Moreover, the collection, storage, use, processing, transmission, provision, disclosure, application and other processing of relevant data all comply with relevant laws, regulations and standards, take necessary confidentiality measures, do not violate public order and good customs, and provide corresponding operation entrances for users or relevant parties to choose to authorize or refuse.

[0071] It should also be noted that in the embodiments of this specification, some existing industry solutions such as certain software, components, models, etc. may be mentioned. They should be regarded as exemplary, and their purpose is only to illustrate the feasibility in the implementation of the technical solutions of this application, but it does not mean that the applicant has already or necessarily used this solution.

[0072] Refer to Figure 1 As shown, the embodiments of this specification provide a method for obtaining fingerprint data based on ultrasonic waves. Specifically, when implementing this method, the following contents may be included:

[0073] S101: Obtain the pollutant information and / or humidity information of the finger;

[0074] S102: Determine the matching target frequency band according to the pollutant information and / or humidity information of the finger;

[0075] S103: According to the target frequency band, control the ultrasonic transducer to emit corresponding ultrasonic signals to obtain the target fingerprint data.

[0076] The above dynamic acquisition method of ultrasonic fingerprint data can be specifically applied to one side of a fingerprint recognition device (or other fingerprint processing devices such as a fingerprint acquisition device). Among them, the above fingerprint recognition device can be specifically applied to an access control system, can also be applied to a smart device (for example, a smart phone), and can also be applied to device systems such as an identity information acquisition system.

[0077] The following takes the fingerprint recognition device as an example for specific description. Regarding other fingerprint processing devices, reference can be made to the relevant embodiments of the fingerprint recognition device, and this specification will not elaborate.

[0078] The above fingerprint recognition device at least includes a fingerprint acquisition area. For example, the above fingerprint acquisition area may be a pressing screen. When a user performs fingerprint recognition, the user can place a finger on the fingerprint acquisition area to collect the required fingerprint data. In some cases, the user can also place a palm on the fingerprint acquisition area to collect corresponding palmprint data.

[0079] Furthermore, a plurality of ultrasonic transducers may be arranged below the fingerprint acquisition area. Among them, the above ultrasonic transducer (or ultrasonic wave transducer) can be specifically understood as a device that can convert electromagnetic energy and mechanical energy (acoustic energy) into each other.

[0080] Specifically, the above ultrasonic transducer at least includes structures such as a piezoelectric element, an electrode, a matching layer, and a backing layer.

[0081] Among them, the above piezoelectric element is usually made of a material with piezoelectric effect. For example, 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 will deform and generate ultrasonic signals. Similarly, when receiving ultrasonic signals, the piezoelectric material will generate corresponding electrical signals. Therefore, the ultrasonic transducer can use the piezoelectric element to transmit and receive ultrasonic signals.

[0082] The above electrodes are attached to both sides of the piezoelectric element and are used to apply voltage or receive the electrical signals generated by the piezoelectric element. The electrodes are usually made of metal (such as silver or platinum), can provide stable conductivity, and can be well combined with the piezoelectric material.

[0083] The above matching layer is used to adjust the acoustic impedance difference between the piezoelectric element and the object to be measured (such as the skin of a finger or air). The matching layer can be a single-layer or multi-layer material, which can reduce the reflection loss of ultrasonic signals while improving the signal transmission efficiency of the ultrasonic transducer.

[0084] The above backing layer is arranged on the back of the piezoelectric element and is usually made of a damping material, which can absorb the backward propagation of ultrasonic signals, mainly used to reduce unnecessary echoes, prevent reflection interference, and enhance the ultrasonic signals propagating forward.

[0085] Specifically, the above ultrasonic transducer is also connected to corresponding transmitting and receiving circuits. Correspondingly, in specific implementation, the ultrasonic transducer can be controlled by the above transmitting circuit to emit different ultrasonic signals. And, the echo signals based on the emitted ultrasonic signals are received through the above receiving circuit; and according to the above echo signals, through corresponding signal processing, the required fingerprint data containing the fingerprint feature information of the user is obtained.

[0086] Among them, the above-mentioned transmitting circuit at least includes: a signal generator. The above-mentioned signal generator can be used to generate an electrical signal to control the ultrasonic transducer to emit a corresponding ultrasonic signal. The above-mentioned signal transmitter may include an oscillator, and the frequency of the ultrasonic signal emitted by the ultrasonic transducer can be adjusted through the oscillator. In this embodiment, the frequency range of the ultrasonic signal emitted by the ultrasonic transducer controlled by the above-mentioned signal generator is: greater than or equal to 1 MHz and less than or equal to 20 MHz.

[0087] Furthermore, the above-mentioned transmitting circuit may also include: a power amplifier and an impedance matching network. The above-mentioned power amplifier is used to amplify the electrical signal generated by the signal generator, and then feed the amplified electrical signal into the ultrasonic transducer. The above-mentioned impedance matching network can be used to adjust the impedance between the ultrasonic transducer and the circuit (such as input impedance, output impedance, etc.) by means of a transformer, an LC circuit, etc., so as to reduce power loss and enable the ultrasonic transducer to receive as much energy as possible.

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

[0089] Furthermore, the above-mentioned receiving circuit may also include: a preamplifier and a filter. The above-mentioned preamplifier is used to amplify 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 too much noise during signal amplification and ensure the signal quality. The above-mentioned filter can be used to filter out the noise signal of the received signal and the signal in the unwanted frequency band. In this embodiment, the transmission frequency of the ultrasonic wave can be used as the center frequency of the filter to ensure that the reflected signal of the relevant ultrasonic wave is obtained after filtering.

[0090] Specifically, the above-mentioned ultrasonic transducer can support a variety of different ultrasonic modes. Correspondingly, the above-mentioned fingerprint recognition device can obtain fingerprint data by emitting corresponding ultrasonic signals based on different ultrasonic modes.

[0091] Among them, the above-mentioned ultrasonic modes include: a focused wave mode and a plane wave mode.

[0092] Specifically, based on the plane wave mode, multiple ultrasonic transducers on the entire surface can be simultaneously driven to emit ultrasonic signals with the same phase and the same frequency, so as to form a plane wave and transmit it to the surface of the finger (or other detected objects such as the palm), and then fast detection and acquisition of fingerprint feature information over a large area can be achieved.

[0093] Based on the focused wave mode, the phases and frequencies of the ultrasonic signals emitted by multiple specified ultrasonic transducers can be started and adjusted, so that the ultrasonic waves can form a focused wave within a specific area, and then detection and acquisition of fingerprint feature information in a small area with high precision can be achieved.

[0094] Among them, the above plane wave mode has the characteristics of low power consumption, high frame rate, fast system response speed, large coverage area, but limited penetration and low precision compared with the focused wave mode.

[0095] The above focused wave mode has the characteristics of high precision, long penetration distance, but high power consumption, low frame rate, and long system response time compared with the plane wave mode.

[0096] The above fingerprint recognition device may further include an environmental sensor; wherein, the environmental sensor is used to collect relevant environmental information. Among them, the above environmental information may include, for example, pollutant information, humidity information, etc. of the detected object (such as a finger) when the user presses the fingerprint collection area; further, it may also include other information that can directly or indirectly reflect the above pollutant information and humidity information, such as weather information, temperature information, season information, location information, etc.

[0097] Specifically, the above environmental sensor may include an intelligent camera; correspondingly, a picture containing the surface of the detected object can be collected through the intelligent camera, and then the pollutant detection model can be used to perform image recognition processing on the picture to obtain the corresponding pollutant information. The above environmental sensor may also include a hygrometer; correspondingly, the humidity value of the position area closest to the fingerprint collection area of the detected object can also be collected through the hygrometer as the corresponding humidity information.

[0098] Of course, it should be noted that the above-listed environmental sensors are only illustrative. In specific implementation, according to specific situations and processing requirements, other types of device equipment can also be introduced and used as environmental sensors. In addition, the fingerprint recognition device can also obtain the required environmental information through corresponding operations based on the echo signals received by the ultrasonic transducers and in combination with the previously emitted ultrasonic signals.

[0099] A control unit (such as a micro control chip, etc.) can also be arranged below the above fingerprint collection area, and the control unit can be specifically electrically connected to the above environmental sensor, transmission circuit, etc.

[0100] The above-mentioned target fingerprint data can be specifically understood as data containing the fingerprint characteristic information of the user and can be used for subsequent data processing such as fingerprint recognition. For example, an echo signal containing the fingerprint feature information of the user, or feature data obtained by further processing the above echo signal.

[0101] Based on the above fingerprint recognition device, when the user presses the fingerprint collection area, the pollution information and / or humidity information of the detection object (such as a finger) when the user presses the fingerprint collection area can be determined first through an environmental sensor or according to the received echo signal; then, according to the pollution information and / or humidity information, different environmental conditions can be distinguished, and a matching target frequency band can be determined; and according to the target frequency band, the ultrasonic transducer can be controlled to emit a corresponding ultrasonic signal to obtain high-quality and low-error target fingerprint data.

[0102] Specifically, for the case where there are pollutants on the surface, since the pollutants cover the surface skin, it is impossible to directly collect the fingerprint details on the skin surface. At this time, it is possible to preferentially select ultrasonic signals in the low-frequency band (for example, 1-5 MHz) to increase the penetration power of the ultrasonic signals, penetrate the surface pollutants, and reach the deeper skin layer to capture the fingerprint features (such as thick valley-ridge lines, the overall shape of the valley-ridge lines, etc.) in the deeper skin layer as a supplement and assistance to obtain fingerprint data that meets the requirements of subsequent processing and has high quality.

[0103] For the case where the surface humidity is high, since the surface moisture will cause certain interference to the ultrasonic signal, it is possible to preferentially select ultrasonic signals in the high-frequency band (for example, 10-20 MHz) to avoid moisture interference and capture the fingerprint details on the skin surface (such as fine valley-ridge lines, sweat pores, fingerprint detail points, etc.) to obtain fingerprint data that meets the requirements of subsequent processing and has high quality.

[0104] For the case where there are no pollutants on the surface and the humidity is normal, it is possible to select ultrasonic signals in the high-frequency band to obtain fingerprint data with high resolution containing recognizable fingerprint information on the skin surface; it is also possible to select ultrasonic signals in the medium-frequency band or normal-frequency band (for example, 5-10 MHz) to balance the resolution and penetration at the same time, and obtain fingerprint data with good effect containing medium-detail features of the fingerprint (such as middle-layer ridge lines, fingerprint fine lines, etc.) and the gap information between the high-frequency band and the low-frequency band.

[0105] In some embodiments, during specific implementation, based on the plane wave mode, the ultrasonic transducer can be controlled to emit a corresponding plane wave as the initial ultrasonic signal to detect whether the user is currently pressing the fingerprint collection area; when it is determined that the user is currently pressing the fingerprint collection area, relevant pollutant information and / or humidity information can be obtained, and a matching target frequency band can be determined according to the pollutant information and / or humidity information; then, according to the target frequency band, the ultrasonic transducer can be controlled to emit a corresponding ultrasonic signal to obtain the target fingerprint data.

[0106] During specific implementation, the pressing position of the user can also be determined according to the detection result of the plane wave; then, according to the pressing position of the user, the emission angle of the ultrasonic transducer can be adjusted to align with the pressing position of the user; then, 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, the plane wave with less power consumption and faster speed can be used to detect and determine whether there is a user pressing the fingerprint collection area first; after it is determined that there is a user pressing the fingerprint collection area, the adjusted focused wave with larger power consumption but higher accuracy and matching the current pollutant information and / or humidity information can be used to collect the required fingerprint data, so that both power consumption and accuracy can be taken into account, and high-quality target fingerprint data can be collected.

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

[0109] Among them, the above-mentioned pollutant type may specifically include at least one of the following: dirt, grease, grit, etc.

[0110] Of course, the above-listed pollutant information and pollutant types are only illustrative. During specific implementation, according to specific application scenarios and processing requirements, other pollutant information and other pollutant types may also be included. This specification does not make any limitations in this regard.

[0111] It should be noted that different types of pollutants and different pollutant thicknesses will have different effects on the reflection of ultrasonic waves. Accordingly, the frequency band of ultrasonic waves can be differentially adjusted for different types of pollutants and different pollutant thicknesses, so as to be able to determine a target frequency band with a higher degree of matching. The specific adjustment method will be described separately later.

[0112] In some embodiments, the above-mentioned obtaining of the pollutant information and / or humidity information of the finger, during specific implementation, may include the following content:

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

[0114] S2: Obtain the pollutant information and / or humidity information of the finger based on the initial echo signal.

[0115] Among them, the above initial ultrasonic signal can be a plane wave signal.

[0116] In specific implementation, the current environmental information can be obtained first, and based on it, the environmental condition of the detection object when the user presses the fingerprint collection area can be estimated; according to the estimation result, a plane wave signal with a suitable frequency band can be determined as the above initial ultrasonic signal; then, the ultrasonic transducer is controlled to emit the initial ultrasonic signal to conduct a preliminary detection on the detection object, and the corresponding initial echo signal is received. Among them, the above preliminary detection can include: the pressing detection of the fingerprint collection area and / or the environmental condition detection.

[0117] In specific implementation, after receiving the above initial echo signal, it can be detected and judged whether the user is currently pressing the fingerprint collection area according to the initial echo signal.

[0118] If it is determined that the user is currently pressing the fingerprint collection area, the pollutant information and / or humidity information of the detection object can be further obtained. On the contrary, if it is determined that the user is not currently pressing the fingerprint collection area, the subsequent data processing can be directly stopped and the device enters the sleep state to save device energy consumption.

[0119] Among them, the obtaining of the pollutant information and / or humidity information of the detection object can specifically include: collecting through the environmental sensor and obtaining the pollutant information and / or humidity information of the detection object according to the corresponding sensor signal; and / or, according to the initial echo signal, determining the pollutant information and / or humidity information of the detection object by calculating and based on the signal quality change data of the initial echo signal.

[0120] In addition, when it is determined that the user is currently pressing the fingerprint collection area, the pressing position of the user at the fingerprint collection area can also be determined according to the initial echo signal through the corresponding positioning algorithm. Then, the pollutant information and / or humidity information, or the target fingerprint data can be collected more accurately according to the above pressing position subsequently.

[0121] In some embodiments, referring to Figure 2 as shown, when the method is specifically implemented, the following content can also be included:

[0122] S1: Collect the current environmental information;

[0123] S2: Determine the matching initial frequency band according to the current environmental information;

[0124] S3: Determine the initial ultrasonic signal according to the initial frequency band.

[0125] In specific implementation, the current environmental information can be collected first through an environmental sensor; then, based on the current environmental information, the environmental condition of the detection object can be estimated; and according to the estimation result of the environmental condition, a matching initial frequency band can be determined from a plurality of preset detection frequency bands.

[0126] Specifically, according to the estimation result, when it is determined that the environmental condition is that there are more pollutants and lower humidity, a detection frequency band with a lower frequency can be selected from a plurality of preset detection frequency bands as the initial frequency band; on the contrary, when it is determined that the environmental condition is less pollution and higher humidity, a detection frequency band with a higher frequency can be selected from a plurality of preset detection frequency bands as the initial frequency band. Furthermore, an initial ultrasonic signal can be determined according to the initial frequency band, and the ultrasonic transducer can be controlled to emit the initial ultrasonic signal for a more targeted preliminary detection.

[0127] In some embodiments, referring to Figure 3 as shown, the above-mentioned obtaining of the pollutant information of the finger according to the initial echo signal, in specific implementation, may include the following content:

[0128] S1: According to the initial echo signal, determine the signal intensity and / or signal-to-noise ratio of the initial echo signal;

[0129] S2: According to the signal intensity and / or signal-to-noise ratio of the initial echo signal, determine whether there are pollutants on the finger;

[0130] S3: When it is determined that there are pollutants on the finger, calculate the attenuation value of the signal intensity and / or the decrease value of the signal-to-noise ratio of the initial echo signal;

[0131] S4: According to the attenuation value of the signal intensity and / or the decrease value of the signal-to-noise ratio, by querying a preset pollutant mapping relationship table, determine the pollutant information.

[0132] In specific implementation, the signal intensity and / or signal-to-noise ratio of the initial echo signal can be compared with preset reference template data (for example, the template reference data of the signal intensity, the template reference data of the signal-to-noise ratio of the signal); according to the comparison result, when it is determined that the signal intensity of the initial echo signal weakens relative to the reference template data (for example, the signal intensity of the initial echo signal is less than the preset template reference data of the signal intensity, and the difference between the two is greater than or equal to a preset first threshold), and / or, the signal-to-noise ratio of the initial echo signal decreases relative to the reference template data (for example, the signal-to-noise ratio of the initial echo signal is less than the template reference data of the signal-to-noise ratio, and the difference between the two is greater than or equal to a preset second threshold), it can be determined that there are pollutants on the detection object. Among them, the above-mentioned preset reference template data can be determined in advance through experimental tests on a detection object without pollutants and with normal humidity.

[0133] According to the comparison result, when it is determined that there are no pollutants in the detection object, the required target fingerprint data can be directly obtained based on the initial echo signal. It is also possible to further detect the humidity of the detection object based on the initial echo signal and / or the sensor signals collected by the environmental sensor; according to the humidity monitoring result, determine whether to re-determine the target frequency band of the ultrasonic signal, and obtain the target fingerprint data according to the target frequency band.

[0134] According to the comparison result, when it is determined that there are pollutants in the detection object, the attenuation value of the signal intensity and / or the decrease value of the signal-to-noise ratio 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] Among them, the preset pollutant mapping relationship table contains multiple data groups; each data group corresponds to a type of pollutant respectively, and contains the range of the decrease amplitude of the attenuation value of the signal intensity and the range of the decrease amplitude of the signal-to-noise ratio corresponding to multiple thickness intervals.

[0136] Before specific implementation, the fingerprint recognition device can be used to pre-conduct experimental tests on sample detection objects with different types and different thicknesses of pollutants; and collect a large amount of experimental test data; according to the experimental test data, through clustering learning, the preset pollutant mapping relationship table is constructed.

[0137] In addition, during specific implementation, multiple ultrasonic transducers can be controlled to generate multiple initial ultrasonic signals simultaneously, and the corresponding multiple initial echo signals can be received; according to the preset reference template data, the initial echo signals with weakened signal intensity and / or decreased signal-to-noise ratio are screened out from the multiple initial echo signals as abnormal signals; then, according to the ultrasonic transducers corresponding to the above abnormal signals, pollutant information such as pollutant location and pollution area is determined.

[0138] In some embodiments, the above-mentioned determination of the target frequency band that matches the pollutant information of the finger, during specific implementation, may include: according to the pollutant information of the finger, by querying the preset pollutant frequency band matching rule set, the target frequency band that matches is determined.

[0139] Among them, the preset pollutant frequency band matching rule set contains multiple preset matching rules, and each preset matching rule corresponds to at least one pollutant type. Further, each preset matching rule may contain multiple preset matching frequency bands, each preset matching frequency band corresponds to a thickness interval, specifically, each preset matching rule may contain three preset matching frequency bands: high frequency band, medium frequency band, and low frequency band. For different pollutant types, the above-mentioned preset matching frequency bands may correspond to different frequency ranges.

[0140] The above-mentioned preset pollutant matching frequency band rule set can specifically be determined in advance through a large number of experimental tests on sample detection objects regarding different pollutant conditions.

[0141] Specifically, first, according to the pollutant type, a matching preset matching rule can be determined from the preset pollutant frequency band matching rule set as the target matching rule; then, according to the pollutant thickness, a preset matching frequency band that matches can be determined from the target matching rule as the target frequency band.

[0142] In some embodiments, after determining the matching target frequency band according to the pollutant information, it is also possible to adjust based on the humidity information on the basis of the above-mentioned target frequency band to obtain an adjusted target frequency band that takes into account both the pollutant information and the humidity information; then use the adjusted target frequency band to control the ultrasonic transducer to emit corresponding ultrasonic signals to obtain target fingerprint data, so that target fingerprint data that eliminates the interference of pollutants and moisture can be obtained.

[0143] Specifically, it can first be detected whether the humidity information is greater than the humidity information template reference data. If it is determined that the humidity information is less than or equal to the humidity information template reference data, it can be determined that the humidity is normal, and at this time, the target frequency band does not need to be adjusted.

[0144] If it is determined that the humidity information is greater than the humidity information template reference data, it can be determined that the humidity is relatively high, and at this time, the 1 / 2 part of the frequency band with relatively large and later frequencies can be intercepted from the target frequency band as the adjusted target frequency band.

[0145] Thus, a target frequency band that matches both the pollutant information and the humidity information can be determined.

[0146] In some embodiments, when the method is specifically implemented, the following content may further be included:

[0147] S1: Determine a matching target signal intensity according to the pollutant information and / or humidity information of the finger;

[0148] S2: According to the target signal intensity, control the ultrasonic transducer to emit corresponding ultrasonic signals to obtain target fingerprint data.

[0149] Specifically, through experimental tests, it is found that when there are more pollutants or higher humidity on the surface of the detection object, by increasing the intensity of the ultrasonic signal, it is also possible to penetrate the pollutants or moisture to a certain extent and collect better fingerprint data.

[0150] Correspondingly, in specific implementation, according to the pollutant information and / or humidity information, when it is determined that there are pollutants on the surface of the detection object and / or the humidity is relatively high, the signal intensity can be correspondingly increased by a corresponding amplitude according to the thickness of the pollutants and / or the humidity value to obtain a matching target signal intensity.

[0151] In some embodiments, according to the pollutant information and / or humidity information, a matching target signal intensity and a matching target frequency band can be determined; then, according to the target signal intensity and the target frequency band, by controlling the ultrasonic transducer to emit corresponding ultrasonic signals, target fingerprint data can be obtained.

[0152] In some embodiments, in the process of obtaining target fingerprint data by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band, the echo signal corresponding thereto can also be received and the emission intensity and / or frequency of the ultrasonic transducer can be dynamically adjusted, 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 effects.

[0153] In some embodiments, the above-mentioned obtaining of target fingerprint data by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band, in specific implementation, may include: controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band; receiving the corresponding echo signal; and obtaining the target fingerprint data containing the fingerprint feature information of the user required through corresponding signal processing according to the echo signal.

[0154] Specifically, after receiving the echo signal, the echo signal can be preprocessed first. Among them, the preprocessing may include: signal filtering processing and / or noise suppression processing. Thus, an identifiable preprocessed echo signal can be obtained, and further, based on the preprocessed echo signal, target fingerprint data with relatively higher accuracy and relatively smaller error can be obtained.

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

[0156] Correspondingly, the above-mentioned obtaining of 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 the ultrasonic signal of one sub-target frequency band.

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

[0158] Specifically, for example, for the high-frequency band (10 - 20 MHz), it can be split into 5 sub-target frequency bands according to the corresponding frequency segmentation rules, which are: 10 - 12 MHz, 12 - 14 MHz, 14 - 16 MHz, 16 - 18 MHz, and 18 - 20 MHz. Then, control the ultrasonic transducer to emit ultrasonic signals based on the above 5 sub-target frequency bands respectively to achieve multi-band scanning and obtain 5 corresponding different echo signals. The 5 echo signals obtained in this way can respectively contain different advantageous characteristics of the corresponding sub-target frequency bands in terms of fingerprint performance.

[0159] Furthermore, the above 5 echo signals can be processed respectively to obtain 5 corresponding sub-target fingerprint data; then, the above 5 sub-target fingerprint data are combined and used to obtain target fingerprint data that can simultaneously integrate the advantageous characteristics of 5 different sub-target frequency bands.

[0160] In some embodiments, after obtaining multiple sub-target fingerprint data, refer to Figure 4 As shown, when the method is specifically implemented, it may further include the following content:

[0161] S1: Respectively extract the corresponding key features from multiple sub-target fingerprint data;

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

[0163] S3: Perform multi-band fusion on multiple key features according to the reliability weight coefficients to obtain a target fingerprint image that meets the requirements; wherein, the target fingerprint image is used for fingerprint recognition.

[0164] When specifically implemented, the fingerprint features that each sub-target frequency band is good at showing can be determined according to the advantageous characteristics of each sub-target frequency band and combined with the line characteristics of different fingerprint features in the fingerprint data.

[0165] Correspondingly, the fingerprint features that each sub-target frequency band is good at showing can be respectively extracted from multiple sub-target fingerprint data to obtain the corresponding key features.

[0166] For example, the basic contour of the deep structure can be extracted as the key fingerprint feature from the sub-target fingerprint data corresponding to the sub-target frequency band with a lower frequency; the fingerprint details on the surface layer can be extracted as the key fingerprint feature from the sub-target fingerprint data corresponding to the sub-target frequency band with a higher frequency; the transitional features can be extracted as the key fingerprint feature from the sub-target fingerprint data corresponding to the sub-target frequency band with a medium frequency.

[0167] Further, according to a preset fusion rule, the reliability degree of each key feature can be determined during subsequent specific fingerprint data processing such as fingerprint recognition; according to the reliability degree, the reliability weight coefficient of the key feature can be determined; and then, according to the reliability weight coefficient, by performing weighted fusion of multiple key features in multiple frequency bands, a target fingerprint image meeting the requirements can be obtained.

[0168] Specifically, a corresponding image processing algorithm (for example, an edge detection algorithm, etc.) can be used to integrate multiple key features in the same image to obtain a fused fingerprint image; then, according to the reliability weight coefficient of each key feature, the display priority of each key feature in the image can be set to obtain a target fingerprint image meeting the requirements.

[0169] Among them, the above target fingerprint image can be used for fingerprint recognition or other related fingerprint data processing.

[0170] Before extracting the corresponding key features from multiple sub-target fingerprint data respectively, alignment processing can be performed on the multiple sub-target fingerprint data first. This is because, due to the different penetration depths of ultrasonic signals in different frequency bands, displacement or deformation may occur between the obtained different sub-target fingerprint data.

[0171] Therefore, affine transformation or non-rigid transformation can be performed on the multiple sub-target fingerprint data first to obtain multiple transformed sub-target fingerprint data to ensure that the features correspond consistently in different sub-target fingerprint data; and then subsequent data processing can be performed based on the multiple transformed sub-target fingerprint data.

[0172] In some embodiments, after obtaining multiple sub-target fingerprint data, when the method is specifically implemented, the following content may further be included:

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

[0174] S2: According to the pollutant information and / or humidity information of the finger, perform weighted operation on the fingerprint feature comparison results in multiple frequency bands to obtain a target fingerprint feature comparison result;

[0175] S3: Determine whether the fingerprint recognition passes according to the target fingerprint feature comparison result.

[0176] Before specific implementation, when a user enters their fingerprint, the fingerprint recognition device can, according to the corresponding frequency segmentation rules, split the entire frequency band (including the high-frequency band, medium-frequency band, and low-frequency band) into multiple sub-frequency bands (which can be denoted as multiple preset frequency bands); then scan according to the multiple sub-frequency bands to obtain multiple fingerprint data based on each sub-frequency band; and then construct a user fingerprint feature template for multiple frequency bands corresponding to this user based on the multiple fingerprint data; where the user fingerprint feature template for each frequency band corresponds to a sub-frequency band respectively. Then establish the correspondence between the user fingerprint feature templates for multiple frequency bands and the identity information of this user; and store the above-mentioned user fingerprint feature templates for multiple frequency bands in the user database to complete the fingerprint entry of this user.

[0177] During specific implementation, after obtaining multiple sub-target fingerprint data, the user database can be queried according to the sub-target frequency bands corresponding to the multiple sub-target fingerprint data to determine the user fingerprint feature templates for multiple frequency bands corresponding to the sub-target frequency bands; then compare the sub-target fingerprint data with the user fingerprint feature templates for the corresponding frequency bands to obtain the fingerprint feature comparison results for multiple frequency bands.

[0178] Furthermore, the reliability weight coefficient for each sub-target frequency band can be determined according to the pollutant information and / or humidity information; then, according to the reliability weight coefficients for each sub-target frequency band, a weighted operation is performed on the fingerprint feature comparison results for multiple frequency bands to obtain the final target fingerprint feature comparison result.

[0179] Furthermore, based on the above target fingerprint feature comparison result, fully considering the specific environmental conditions of the current detection object, it can be accurately determined whether the fingerprint recognition passes.

[0180] In some embodiments, when the method is specifically implemented, the following content may further be included:

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

[0182] S2: Construct and store user fingerprint feature templates for multiple frequency bands based on the fingerprint data of multiple frequency bands.

[0183] During specific acquisition, the acquired fingerprint data can be stored in a folder corresponding to the preset frequency band according to the preset frequency band; or, a frequency band label for indicating the preset frequency band can be added to the acquired fingerprint data.

[0184] In specific implementation, user fingerprint feature templates of multiple frequency bands can be constructed and stored based on fingerprint data of multiple frequency bands, and the user fingerprint feature templates of the above multiple frequency bands can be stored at the same time. User fingerprint feature templates of multiple frequency bands can also be combined to construct a fingerprint fusion template that simultaneously integrates user fingerprint feature targets of multiple frequency bands for subsequent use.

[0185] In some embodiments, after obtaining the contaminant information and / or humidity information of the finger, the method may also include the following contents when it is implemented: based on the contaminant information of the finger, when it is determined that the finger has a lot of contaminants, a first prompt information about cleaning the finger can be generated and accessed; and / or, based on the humidity information of the finger, when it is determined that the humidity of the finger is high, a second prompt information about drying the finger can be generated and accessed.

[0186] As can be seen from the above, based on the ultrasonic fingerprint data acquisition method provided in the embodiment of this specification, the contaminant information and / or humidity information of the finger can be obtained first; then, according to the contaminant information and / or humidity information of the finger, the matching target frequency band can be determined; according to the target frequency band, the target fingerprint data can be obtained by controlling the ultrasonic transducer to emit the corresponding ultrasonic signal. Thus, it is possible to determine and intelligently determine the matching target frequency band according to the actual environmental conditions of the finger; then, based on the target frequency band, the target fingerprint data can be obtained by controlling the emission of the corresponding ultrasonic signal, thereby effectively reducing the error interference caused by environmental factors such as pollutants and moisture in the finger environment, accurately obtaining fingerprint data containing one or more depth information, and being able to be well applied to subsequent fingerprint data processing such as fingerprint recognition, and having high quality.

[0187] See also Figure 5 As shown, the embodiment of this specification also provides another method for acquiring fingerprint data based on ultrasound. When the method is implemented specifically, it may include the following contents:

[0188] S501: Controlling the ultrasonic transducer to transmit an initial ultrasonic signal and receive a corresponding initial echo signal;

[0189] S502: Determine a matching target frequency band according to the initial echo signal;

[0190] S503: According to the target frequency band, the target fingerprint data is acquired by controlling the ultrasonic transducer to transmit a corresponding ultrasonic signal.

[0191] The initial ultrasonic signal may be an ultrasonic signal based on a high frequency band.

[0192] Correspondingly, based on the initial echo signal, an initial fingerprint data (e.g., an initial fingerprint image) that pays relatively more attention to presenting the surface fingerprint features of the detection object can be obtained; and then, based on the initial fingerprint data, it can be determined whether there are pollutants and / or moisture on the surface of the detection object.

[0193] If there are no pollutants and no moisture, the initial fingerprint data can be directly determined as the target fingerprint data that meets the requirements.

[0194] On the contrary, if there are pollutants and / or moisture, the pollutant information and / or humidity information can be further obtained based on the initial echo signal; then, based on the pollutant information and / or humidity information, a matching target frequency band can be determined; according to the target frequency band, by controlling the ultrasonic transducer to emit corresponding ultrasonic signals, the target fingerprint data that meets the requirements can be obtained.

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

[0196] Correspondingly, according to the target frequency band, by controlling the ultrasonic transducer to emit corresponding ultrasonic signals, multiple sub-target fingerprint data can be obtained; among them, one sub-target fingerprint data corresponds to the ultrasonic signal of one sub-target frequency band.

[0197] Furthermore, subsequently, multiple sub-target fingerprint data can be combined and used to construct the target fingerprint data with rich information and good effect.

[0198] This specification also provides another method for obtaining fingerprint data based on ultrasonic waves. When specifically implemented, it may include the following content:

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

[0200] S2: Determine the matching target frequency band according to the pollutant information and / or humidity information on the fingerprint acquisition area;

[0201] S3: According to the target frequency band, by controlling the ultrasonic transducer to emit corresponding ultrasonic signals, obtain the target fingerprint data.

[0202] In some embodiments, after obtaining the pollutant information and / or humidity information on the fingerprint acquisition area, when the method is specifically implemented, it may further include: according to the pollutant information of the fingerprint acquisition area, when it is determined that there are many pollutants in the fingerprint acquisition area, the third prompt information about cleaning the fingerprint acquisition area can be generated and reached; and / or, according to the humidity information of the fingerprint acquisition area, when it is determined that the humidity of the fingerprint acquisition area is high, the fourth prompt information about drying the fingerprint acquisition area can be generated and reached.

[0203] This specification also provides another method for obtaining fingerprint data based on ultrasonic waves. Specifically, when implemented, it may include the following:

[0204] S1: According to the first frequency band, control the ultrasonic transducer to emit a first ultrasonic signal to obtain first fingerprint data;

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

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

[0207] Among them, the above first frequency band can be a frequency band that focuses on collecting fingerprint features on the skin surface of the detection object. For example, a high-frequency band.

[0208] Specifically, in one case, it can be judged whether the first fingerprint data meets the preset processing requirements by detecting whether the fingerprint features on the skin surface in the first fingerprint data are clear and complete. If it is clear and complete, it is determined that it meets the preset processing requirements, and the first fingerprint data can be directly determined as the target fingerprint data.

[0209] If the clarity of the first fingerprint data is less than the preset clarity threshold, and / or the integrity is less than the preset integrity threshold, it is judged that the first fingerprint data does not meet the preset processing requirements. At this time, relevant pollutant information and / or humidity information can be obtained; and according to the pollutant information and / or humidity information, the matching second frequency band can be determined; then switch and, according to the second frequency band, control the ultrasonic transducer to emit a second ultrasonic signal to obtain second fingerprint data as the target fingerprint data finally used for subsequent fingerprint data processing.

[0210] In another case, 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 is used to perform fingerprint comparison with the first user fingerprint feature template to obtain the first comparison result.

[0211] According to the first comparison result, in the case where it is determined that the fingerprint recognition is passed, the relevant fingerprint data processing is completed. On the contrary, in the case where it is determined that the fingerprint recognition fails, it is detected whether the first fingerprint data is clear and complete. If the clarity of the first fingerprint data is less than the preset clarity threshold, and / or the integrity is less than the preset integrity threshold, it is determined that the first fingerprint data does not meet the preset processing requirements. At this time, it can be switched and, according to the second frequency band, control the ultrasonic transducer to emit a second ultrasonic signal to obtain second fingerprint data. Among them, the frequency of the second frequency band is less 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 perform fingerprint comparison with the second user fingerprint feature template to obtain a second comparison result.

[0213] According to the second comparison result, when it is determined that the fingerprint recognition is passed, complete the relevant fingerprint data processing. On the contrary, when it is determined that the fingerprint recognition fails, detect whether the second fingerprint data is clear and complete. If the clarity of the second fingerprint data is less than the preset clarity threshold and / or the integrity is less than the preset integrity threshold, it is determined that the second fingerprint data does not meet the preset processing requirements. At this time, it is possible to switch and obtain the third fingerprint data by controlling the ultrasonic transducer to emit a third ultrasonic signal according to the third frequency band. Among them, the frequency of the third frequency band is less than that of the second frequency band.

[0214] And so on until the fingerprint recognition is passed or there is no ultrasonic signal of the next frequency band available for switching.

[0215] An embodiment of this specification provides an electronic device, as shown in Figure 6 shown. Among them, the electronic device includes a network communication port 601, a processor 602, and a memory 603. The above structures are connected by internal cables so that each structure can perform specific data interactions.

[0216] Among them, the network communication port 601 can specifically be used to obtain the pollutant information and / or humidity information of the finger.

[0217] The processor 602 can specifically be used to determine a matching target frequency band according to the pollutant information and / or humidity information of the finger; and according to the target frequency band, control the ultrasonic transducer to emit a corresponding ultrasonic signal to obtain the target fingerprint data.

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

[0219] Based on the above method, the relevant structural performance of the electronic device can be effectively utilized, the data processing speed of the electronic device can be improved, and the data processing for obtaining fingerprint data based on ultrasonic waves can be efficiently realized.

[0220] In this embodiment, the network communication port 601 can be bound to different communication protocols, so as to send or receive different data as a virtual port. For example, the network communication port can be a port responsible for web data communication, or a port responsible for FTP data communication, or a port responsible for mail data communication. In addition, 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, CDMA, etc.; it can also be a Wifi chip; it can also 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, for example, a microprocessor or a processor, and a computer-readable medium storing computer-readable program code (such as software or firmware) executable by the (micro)processor, logic gates, switches, application specific integrated circuit (ASIC), programmable logic controller, and embedded microcontroller, etc. This specification does not make any limitations.

[0222] In this embodiment, the memory 603 can include multiple levels. In a digital system, anything that can store binary data can be a memory; in an integrated circuit, a circuit with a storage function without a 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] The embodiment of this specification also provides a computer-readable storage medium based on the above ultrasonic-based fingerprint data acquisition method. The computer-readable storage medium stores computer program instructions, which when executed, implement: obtaining the pollutant information and / or humidity information of a finger; determining a matching target frequency band according to the pollutant information and / or humidity information of the finger; and obtaining 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 above 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 set according to the standards specified by the communication protocol and is an interface for network connection communication.

[0225] In this embodiment, the functions and effects specifically implemented by the program instructions stored in the computer-readable storage medium can be explained in comparison with other embodiments, and will not be elaborated here.

[0226] The embodiments of this specification also provide a computer program product, which at least includes a computer program. When the computer program is executed by a processor, the following method steps are implemented: obtaining pollutant information and / or humidity information of a finger; determining a matching target frequency band according to the pollutant information and / or humidity information of the finger; and obtaining target fingerprint data by controlling an ultrasonic transducer to emit a corresponding ultrasonic signal according to the target frequency band.

[0227] Refer to Figure 7 As shown, the embodiments of this specification also provide a fingerprint data acquisition device based on ultrasonic waves. The device may specifically include the following structural modules:

[0228] A first acquisition module 701, which may specifically be used to obtain pollutant information and / or humidity information of a finger;

[0229] A determination module 702, which may specifically be used to determine a matching target frequency band according to the pollutant information and / or humidity information of the finger;

[0230] A second acquisition module 703, which may specifically be used to obtain target fingerprint data by controlling an ultrasonic transducer to emit a corresponding ultrasonic signal according to the target frequency band.

[0231] In some embodiments, when the first acquisition module 701 is specifically implemented, the pollutant information and / or humidity information of the finger may be obtained in the following manner: controlling the ultrasonic transducer to emit an initial ultrasonic signal and receiving a corresponding initial echo signal; and obtaining the pollutant information and / or humidity information of the finger according to the initial echo signal.

[0232] In some embodiments, when the device is specifically implemented, it may also be used to: collect current environmental information; determine a matching initial frequency band according to the current environmental information; and determine an initial ultrasonic signal according to the initial frequency band.

[0233] In some embodiments, the pollutant information of the finger may be obtained according to the initial echo signal in the following manner: determining the signal intensity and / or signal-to-noise ratio of the initial echo signal according to the initial echo signal; determining whether there is a pollutant on the finger according to the signal intensity and / or signal-to-noise ratio of the initial echo signal; calculating the attenuation value of the signal intensity and / or the decrease value of the signal-to-noise ratio of the initial echo signal when it is determined that there is a pollutant on the finger; and determining the pollutant information by querying a preset pollutant mapping relationship table according to the attenuation value of the signal intensity 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, pollution location, etc.

[0235] In some embodiments, when the determining module 702 is specifically implemented, the following method may be used to determine a matching target frequency band according to the pollutant information of the finger: According to the pollutant information of the finger, by querying a preset pollutant frequency band matching rule set, a matching target frequency band is determined.

[0236] In some embodiments, when the device is specifically implemented, it may also be used to: determine a matching target signal strength according to the pollutant information and / or humidity information of the finger; according to the target signal strength, control the ultrasonic transducer to emit a corresponding ultrasonic signal to obtain target fingerprint data.

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

[0238] Correspondingly, when the device is specifically implemented, it may control the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band to obtain multiple sub-target fingerprint data; among them, one sub-target fingerprint data corresponds to an ultrasonic signal of one sub-target frequency band.

[0239] In some embodiments, after obtaining multiple sub-target fingerprint data, when the device is specifically implemented, it may also be used to: respectively extract corresponding key features from the multiple sub-target fingerprint data; 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 obtaining multiple sub-target fingerprint data, when the device is specifically implemented, it may also be used to: use the multiple sub-target fingerprint data to perform fingerprint feature comparison with the user fingerprint feature templates of multiple corresponding frequency bands respectively to obtain fingerprint feature comparison results of multiple frequency bands; perform weighted calculation on the fingerprint feature comparison results of multiple frequency bands according to the pollutant information and / or humidity information of the finger to obtain a target fingerprint feature comparison result; determine whether the fingerprint recognition passes according to the target fingerprint feature comparison result.

[0241] In some embodiments, when the device is specifically implemented, it may also be used to: control the ultrasonic transducer to sequentially or separately emit ultrasonic signals of multiple preset frequency bands according to a preset acquisition rule to collect fingerprint data of multiple frequency bands; construct and store user fingerprint feature templates of multiple frequency bands according to the fingerprint data of multiple frequency bands.

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

[0243] A control module for controlling the ultrasonic transducer to emit an initial ultrasonic signal and receiving the corresponding initial echo signal;

[0244] A determination module for determining a matching target frequency band according to the initial echo signal;

[0245] An acquisition module for acquiring 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 a plurality of sub-target frequency bands;

[0247] Correspondingly, when the above device is specifically implemented, a plurality of sub-target fingerprint data can be acquired by controlling the ultrasonic transducer to emit corresponding ultrasonic signals according to the target frequency band; wherein, one sub-target fingerprint data corresponds to the 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 specifically implemented by computer chips or entities, or by products with certain functions. For the convenience of description, when describing the above device, various modules are described separately according to their functions. Of course, when implementing this specification, the functions of each module can be implemented in the same or multiple software and / or hardware, or the modules implementing the same function can be realized by a combination of multiple sub-modules or sub-units, etc. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function 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. Another point is that the couplings or direct couplings or communication connections shown or discussed with each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical or other forms.

[0249] As can be seen from the above, based on the ultrasonic-based fingerprint data acquisition device provided by the embodiments of this specification, the error interference caused by environmental factors such as pollutants and moisture in the finger environment can be effectively reduced, and fingerprint data containing one or more depth information can be accurately obtained, and it can be better applied to subsequent fingerprint data processing such as fingerprint recognition and fingerprint data with higher quality.

[0250] In a specific scenario example, the ultrasonic-based fingerprint data acquisition method provided by this specification can be applied to implement fingerprint scan unlocking, and the specific implementation process can refer to the following content.

[0251] In this scenario example, considering that the existing methods use ultrasonic signals of a single frequency for scanning, their penetration ability at different depths is limited, and they cannot capture all fingerprint details, especially in the case where the surface has dirt (e.g., contaminants) or moisture (e.g., water vapor). Relying solely on the verification of a single frequency band during the unlocking phase is vulnerable to changes in environmental and surface conditions, reducing the security of unlocking.

[0252] To address the above problems and combined with the root causes of these problems, this scenario example considers capturing fingerprint information of different depths and features through dynamically adjusting the transmission frequency and multi-band scanning, thereby reducing the interference caused by surface contaminants and improving the recognition accuracy and security. First, during the fingerprint detection phase, ultrasonic signals of multiple frequency bands are used for scanning. Different frequency bands can penetrate different depths of the finger surface to capture more detailed features. By covering more fingerprint features with multi-band signals, the interference caused by surface contaminants (such as dirt and grease) is reduced. Second, according to the signal quality detected in real time, the transmission frequency and intensity of the ultrasonic waves are dynamically adjusted. High-frequency signals are used to capture surface details, and low-frequency signals are used to penetrate deeper dirt layers. Through the dynamic adjustment of the frequency, the best signal quality can be ensured under different surface conditions. Third, the scanning results of different frequency bands are fused, and through image processing algorithms, high-resolution fingerprint images are generated by integrating multi-band data. Combining the advantages of multi-bands, more comprehensive and detailed fingerprint images are provided, improving the recognition accuracy and reliability. In addition, through multi-band verification during the fingerprint enrollment and unlocking phases, the security of unlocking is significantly improved. The multi-band features are recorded during the enrollment phase, and these features are re-scanned and verified during the unlocking phase to ensure the accuracy and security of fingerprint matching.

[0253] Specifically, it includes the following parts: Initialization: During the fingerprint enrollment phase, the system initializes multiple ultrasonic transducers (or called ultrasonic transducers), configured to work at different frequency bands. Ensure that scanning can be performed at different frequency bands to obtain multi-level fingerprint features (such as target fingerprint data) on and inside the finger surface. Multi-band scanning: Start the multi-band scanning mode. The ultrasonic transducers sequentially emit ultrasonic signals at different frequency bands. The signals of each frequency band penetrate different depths of the finger surface to capture more detailed features. By covering more fingerprint features with signals of different frequency bands, the depth and detail performance of the fingerprint image are improved, and the interference caused by surface contaminants (such as dirt and grease) is reduced. Data acquisition: The ultrasonic transducers receive the reflected signals and record the scanning data of each frequency band respectively. The acquisition of multi-band data can provide comprehensive fingerprint information and improve the clarity and resolution of the image.

[0254] In specific implementations, the frequency bands that can be used generally cover high frequencies (10 - 20 MHz) (for example, the high - frequency band) and low frequencies (1 - 5 MHz) (for example, the low - frequency band). Among them, high - frequency ultrasonic waves can capture surface details but have poor penetration, being suitable for processing relatively clean surfaces; low - frequency ultrasonic waves have strong penetration and can penetrate dirt and grease, but have lower resolution, so they are suitable for dirtier surfaces. Using these two frequency bands in combination can reduce the interference caused by surface contaminants.

[0255] Specifically, it can be divided into 3 frequency bands, including: the high - frequency band, the low - frequency band, and the medium - frequency band.

[0256] Among them, the low - frequency band (1 - 5 MHz), function: Low - frequency ultrasonic waves have strong penetration and can penetrate surface contaminants such as dirt and grease, and can reach deeper skin layers of the finger. Although its resolution is low, it can capture deeper fingerprint features, such as thick ridges and the overall shape of the ridges. Features that can be extracted: thick ridges, valley lines, and the contour of the deep - layer fingerprint structure, and these features can still be clearly recorded when the surface is contaminated.

[0257] The medium - frequency band (5 - 10 MHz), function: Medium - frequency ultrasonic waves achieve a balance between resolution and penetration. It can both penetrate the surface dirt and capture more surface fingerprint detail features. Features that can be extracted: medium - detail fingerprint features, such as middle - layer ridges, fingerprint fine lines, and some minutiae features. These features are between the deep and surface layers and can supplement the gap information between the low - frequency and high - frequency bands.

[0258] The high - frequency band (10 - 20 MHz), function: The ultrasonic waves in the high - frequency band have weak penetration but high resolution, and can clearly capture surface details. It is suitable for clean or relatively clean surfaces. Features that can be extracted: surface detail features, such as fine ridges, sweat pores, minutiae information of fingerprints, etc. These details are crucial for the uniqueness of fingerprints but may be interfered with in the presence of surface contamination.

[0259] In specific implementations, the ultrasonic waves can be dynamically frequency - adjusted in the following way:

[0260] a) Real - time monitoring of signal quality: 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. Ensure that dynamic adjustments can be made according to the real - time signal quality to optimize the scanning effect.

[0261] b) Dynamically adjust the emission frequency and intensity: Dynamically adjust the emission frequency and intensity of ultrasonic waves according to real-time monitoring data. When more surface dirt is detected, the system can increase the emission intensity or switch to a higher frequency to improve the signal penetration. By dynamically adjusting the frequency and intensity, it adapts to different surface conditions to ensure the best signal quality in complex environments.

[0262] During specific implementation, the system can judge 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 that there is dirt or other interfering substances on the fingerprint surface. In this case, the system will consider the scanning conditions to be poor and needs to dynamically adjust the emission parameters.

[0263] Specific adjustments can include: adjustment of the emission intensity and adjustment of the emission frequency.

[0264] Among them, the adjustment of the above emission intensity can include the following: If the system detects a decrease in the quality of the reflected signal, it can improve the signal penetration by increasing the emission intensity of ultrasonic waves. The specific adjustment method is to increase the output voltage or power of the drive module, thereby increasing the intensity of the emitted signal. The increase amount of the emission intensity can be dynamically adjusted according to the signal quality. For example, the greater the decrease in the signal-to-noise ratio, the greater the increase amount of the emission intensity. The adjustment of the above emission frequency can include the following: The system can also switch to a more appropriate frequency band according to the detected signal condition. For example, when more surface dirt is detected, the system may switch to a lower frequency (such as 3 MHz) to enhance the penetration ability. On the contrary, if it is necessary to capture surface details, it switches to a higher frequency (such as 15 MHz).

[0265] In specific implementation, for the data collected in multiple frequency bands, frequency band marking and data separation can be performed: The system can mark the scanning data for each frequency band. During data collection, the ultrasonic signals transmitted in different frequency bands are respectively recorded and carry the identification information of the frequency band. The data of each frequency band can be stored in a separate data structure for subsequent processing. For example, the scanning data in the 1 - 5 MHz frequency band is stored in a folder or a database entry, while the 10 - 20 MHz frequency band is stored in another folder. A mapping table can also be used to manage the scanning data of different frequency bands. The system records the corresponding depths and features of different frequency bands through a table during the scanning process. For example, the low frequency (1 - 5 MHz) is responsible for recording the ridge information of the deeper layers of the finger, while the high frequency (10 - 20 MHz) records the minutiae information of the surface layer. Through this mapping table, after scanning, the system can quickly locate and extract the scanning data corresponding to a specific frequency band for further processing. Time - slicing recording can also be used to manage the data of different frequency bands. If the system switches between different frequency bands in chronological order for scanning, the system can record the time points of each frequency band switch and classify the received reflected signals during the corresponding time periods into the corresponding frequency bands. 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 the data of different frequency bands are distinguished and can be traced back to a specific frequency band.

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

[0267] In specific implementation, fusion processing can also be performed on the multi - band data. Specifically, it can include the following:

[0268] a) Data fusion: The data obtained from scanning in different frequency bands is fused. Using image - processing algorithms, the fingerprint features in the low - frequency band, medium - frequency band, and high - frequency band are integrated into a comprehensive fingerprint image. Through the fusion of multi - 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, minutiae, etc., are extracted from the fused image. Image - processing techniques such as denoising and enhancement are used to optimize the fused fingerprint image and improve the image quality. Image optimization enhances the detail performance and ensures the accurate extraction and recognition of fingerprint features.

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

[0271] Image alignment: The fingerprint images of different bands first need to be aligned. Due to the different penetration depths of signals in different bands, displacement or deformation may occur. These images are aligned through image registration algorithms (such as affine transformation or non-rigid transformation) to ensure that the feature points of all bands correspond consistently.

[0272] Weighted average method: The images of different bands can be fused using the weighted average method. Generally, the low-frequency band image can be used to provide the basic contour of the deep structure, while the high-frequency band image is used to provide the fine features of the surface layer. The medium-frequency band image serves as an intermediate layer for transition. Data of each band are assigned different weights according to their reliability. For example, the detail components of the high-frequency image may be assigned higher weights, while the low-frequency image is more used for supplementing the deep contour.

[0273] Feature extraction and fusion: Key fingerprint feature points, such as ridge lines, valley lines, minutiae points, etc., are extracted from the fused image. Corresponding features are extracted from the images of each band through image processing algorithms (such as edge detection, feature extraction algorithms) and integrated in the fused image. For example, the detailed features of the high-frequency band will be preferentially displayed in the final image, while the rough contour of the low-frequency band is used for supplementation.

[0274] In specific implementation, during the unlocking stage, the system restarts the multi-band ultrasonic scanning and can use the same bands as in the enrollment stage for fingerprint scanning. Ensure that the scanning in the unlocking stage is consistent with that in the enrollment stage to improve the consistency and accuracy of recognition.

[0275] During the unlocking process, real-time comparison and dynamic adjustment can be performed: The multi-band fingerprint data obtained from real-time scanning are compared with the pre-enrolled multi-band fingerprint template. According to the signal quality detected in real time, the transmission frequency and intensity are dynamically optimized to reduce interference caused by surface contaminants (such as dirt, grease). Through multi-band verification and dynamic adjustment, the security and accuracy of the unlocking stage are improved to ensure that only a real and complete fingerprint can unlock the device.

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

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

[0278] b) Template creation in the enrollment stage: When enrolling fingerprints, the system creates separate fingerprint templates for each frequency band. For example, the template of the low-frequency band records deeper ridge lines and valley lines, the template of the mid-frequency band records mid-layer features, and the template of the high-frequency band records surface details.

[0279] For example, low-frequency band (3 MHz): The system first uses the low-frequency band for scanning to capture the thick ridge lines deep in the fingerprint. The data of this frequency band can penetrate surface dirt or moisture. Mid-frequency band (10 MHz): The mid-frequency band scanning is used to capture the mid-layer features of the fingerprint, mainly including minutiae features and some mid-layer valley-ridge lines. High-frequency band (20 MHz): The high-frequency band scanning is used to capture the surface details of the fingerprint, such as pores and subtle changes in fingerprint patterns. The scanning of this frequency band is suitable for clean surfaces and can provide high-resolution surface images. The comparison results of each frequency band are output separately and stored in the verification buffer of the system.

[0280] c) Comparison in the unlocking stage: When unlocking, the system sequentially or in batches captures the fingerprint images of each frequency band and compares them with the templates of the corresponding frequency bands in the enrollment stage respectively. The comparison process is independent of other frequency bands, which means that the comparison results of each frequency band are based on its own features and do not rely on the fusion of multi-frequency band data.

[0281] Through the above scenario example, the system uses the integrated environmental sensor to detect the dirt, humidity or temperature conditions on the finger surface in real time and dynamically selects the optimal scanning frequency band according to the detected conditions. For example, when more dirt is detected on the fingerprint surface, the system preferentially selects the low-frequency band for scanning to enhance the penetration of ultrasonic waves; when the surface is clean, it preferentially selects the high-frequency band to capture details. After the system independently verifies each frequency band, it comprehensively evaluates the comparison results by combining a weighted algorithm. According to the contribution degree of different frequency bands in the unlocking process, the system assigns different weights to each frequency band. For example, in the case of a clean finger surface, the system will assign a higher weight to the verification result of the high-frequency band to ensure that more surface details are captured. Under the surface condition with more dirt, the system will assign a higher weight to the verification result of the low-frequency band to utilize its stronger penetration. Through weighted evaluation, the system can flexibly adjust the comparison priorities of each frequency band according to different environmental conditions and reduce misjudgments caused by the failure of a single frequency band.

[0282] Thus, more fingerprint features can be captured through the multi-frequency band scanning mode, improving the image quality. The adaptability of the system under dirty fingers and complex surface conditions is enhanced through dynamic frequency adjustment and adaptive filtering technology. By adjusting the transmission frequency and signal processing parameters in real time, the best detection effect is ensured. Through multi-frequency band verification in the fingerprint enrollment and unlocking stages, the security of unlocking is significantly improved.

[0283] Although this specification provides method operation steps as described in the embodiments or flowcharts, more or fewer operation steps may be included based on conventional or non-creative means. The order of steps listed in the embodiments is only one way among many execution orders of steps and does not represent the only execution order. When the actual device or client product is executed, it may be executed in the order of the method shown in the embodiments or the drawings or executed in parallel (for example, in a parallel processor or multi-threaded processing environment, or even in a distributed data processing environment). The terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, product or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, product or device. Without further limitation, there is no exclusion of additional identical or equivalent elements in the process, method, product or device comprising the said elements. Words such as first, second, etc. are used to denote names and do not denote any particular order.

[0284] As is also known to those skilled in the art, in addition to implementing the controller in the form of pure computer-readable program code, the method steps can be logically programmed to enable the controller to implement the same functions in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. Therefore, such a controller can be regarded as a hardware component, and the devices included therein for implementing various functions can also be regarded as the structures within the hardware component. Or even, the devices for implementing various functions can be regarded as either software modules for implementing the method or structures within the hardware component.

[0285] This specification may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc. that perform specific tasks or implement specific abstract data types. This specification may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules may be located in local and remote computer-readable storage media including storage devices.

[0286] From the descriptions of the above embodiments, those skilled in the art can clearly understand that this specification can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of this specification can essentially be embodied in the form of a software product, which can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, mobile terminal, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of this specification.

[0287] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, reference can be made to each other. The key point of each embodiment is to illustrate the differences from other embodiments. This specification can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multi-processor systems, microprocessor-based systems, set-top boxes, programmable electronic devices, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, and so on.

[0288] Although this specification is depicted through embodiments, those of ordinary skill in the art know that this specification has many variations and changes without departing from the spirit of this specification. It is hoped that the appended claims will cover these variations and changes without departing from the spirit of this specification.

Claims

1. A method for obtaining fingerprint data based on ultrasonic waves, characterized in that, Including: Obtaining the pollutant information and / or humidity information of the finger; Determining a matching target frequency band according to the pollutant information and / or humidity information of the finger; According to the target frequency band, controlling the ultrasonic transducer to emit a corresponding ultrasonic signal and obtaining target fingerprint data.

2. The method according to claim 1, wherein Obtaining the pollutant information and / or humidity information of the finger includes: Controlling the ultrasonic transducer to emit an initial ultrasonic signal and receiving a corresponding initial echo signal; Obtaining the pollutant information and / or humidity information of the finger according to the initial echo signal.

3. The method according to claim 2, wherein The method further includes: Collecting the current environmental information; Determining a matching initial frequency band according to the current environmental information; Determining an initial ultrasonic signal according to the initial frequency band.

4. The method according to claim 2, wherein Obtaining the pollutant information of the finger according to the initial echo signal includes: Determining the signal intensity and / or signal-to-noise ratio of the initial echo signal according to the initial echo signal; Determining whether there is a pollutant on the finger according to the signal intensity and / or signal-to-noise ratio of the initial echo signal; When it is determined that there is a pollutant on the finger, calculating the attenuation value of the signal intensity and / or the decrease value of the signal-to-noise ratio of the initial echo signal; Determining the pollutant information by querying a preset pollutant mapping relation table according to the attenuation value of the signal intensity and / or the decrease value of the signal-to-noise ratio.

5. The method according to claim 4, characterized in that The pollutant information includes at least one of the following: pollutant type, pollutant thickness, pollutant area, pollution position.

6. The method according to claim 4, wherein Determining a matching target frequency band according to the pollutant information of the finger includes: Determining a matching target frequency band by querying a preset pollutant frequency band matching rule set according to the pollutant information of the finger.

7. The method according to claim 1, characterized in that, The method further includes: Determining a matching target signal intensity according to the pollutant information and / or humidity information of the finger; According to the target signal intensity, controlling the ultrasonic transducer to emit a corresponding ultrasonic signal and obtaining target fingerprint data.

8. The method according to claim 1, wherein The target frequency band includes a plurality of sub-target frequency bands; Correspondingly, according to the target frequency band, controlling the ultrasonic transducer to emit corresponding ultrasonic signals to obtain a plurality of sub-target fingerprint data; wherein, one sub-target fingerprint data corresponds to an ultrasonic signal of one sub-target frequency band.

9. The method according to claim 8, characterized in that, After obtaining a plurality of sub-target fingerprint data, the method further includes: Respectively extracting corresponding key features from the plurality of sub-target fingerprint data; Determining the reliability weight coefficient of the key features according to a preset fusion rule; Performing multi-band fusion on the plurality of 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.

10. The method according to claim 8, characterized in that After obtaining a plurality of sub-target fingerprint data, the method further includes: Using the plurality of sub-target fingerprint data to perform fingerprint feature comparison with the user fingerprint feature templates of the corresponding plurality of frequency bands respectively to obtain fingerprint feature comparison results of the plurality of frequency bands; Performing a weighted operation on the fingerprint feature comparison results of the plurality of frequency bands according to the pollutant information and / or humidity information of the finger to obtain a target fingerprint feature comparison result; Determining whether the fingerprint recognition passes according to the target fingerprint feature comparison result.

11. The method according to claim 10, wherein The method further includes: Control the ultrasonic transducer to sequentially or in batches transmit ultrasonic signals of multiple preset frequency bands according to the preset acquisition rules, and collect fingerprint data of multiple frequency bands; Construct and store user fingerprint feature templates of multiple frequency bands according to the fingerprint data of multiple frequency bands.

12. A method for obtaining fingerprint data based on ultrasonic waves, characterized in that, Including: Control the ultrasonic transducer to emit an initial ultrasonic signal and receive the corresponding initial echo signal; Determine the target frequency band that matches according to the initial echo signal; According to the target frequency band, control the ultrasonic transducer to emit the corresponding ultrasonic signal to obtain the target fingerprint data.

13. The method according to claim 12, wherein The target frequency band includes multiple sub-target frequency bands; Correspondingly, according to the target frequency band, control the ultrasonic transducer to emit the corresponding ultrasonic signal to obtain multiple sub-target fingerprint data; among them, one sub-target fingerprint data corresponds to the ultrasonic signal of one sub-target frequency band.

14. A method for obtaining fingerprint data based on ultrasonic waves, characterized in that, Including: Obtain the pollutant information and / or humidity information on the fingerprint acquisition area; Determine the target frequency band that matches according to the pollutant information and / or humidity information on the fingerprint acquisition area; According to the target frequency band, control the ultrasonic transducer to emit the corresponding ultrasonic signal to obtain the target fingerprint data.

15. A method for obtaining fingerprint data based on ultrasonic waves, characterized in that, Including: According to the first frequency band, control the ultrasonic transducer to emit the first ultrasonic signal to obtain the first fingerprint data; Determine whether the first fingerprint data meets the preset processing requirements; In the case where it is determined that the first fingerprint data does not meet the preset processing requirements, switch and according to the second frequency band, control the ultrasonic transducer to emit the second ultrasonic signal to obtain the second fingerprint data.

16. A fingerprint data acquisition device based on ultrasonic waves, characterized in that, Including: The first acquisition module is used to obtain the pollutant information and / or humidity information of the finger; The determination module is used to determine the target frequency band that matches according to the pollutant information and / or humidity information of the finger; The second acquisition module is used to obtain the target fingerprint data according to the target frequency band by controlling the ultrasonic transducer to emit the corresponding ultrasonic signal.

17. An electronic device, characterized in that, Including a processor and a memory for storing instructions executable by the processor. When the processor executes the instructions, the steps of the method described in any one of claims 1 to 15 are implemented.

18. A computer-readable storage medium, characterized in that, A computer instruction is stored thereon. When the instruction is executed by the processor, the steps of the method described in any one of claims 1 to 15 are implemented.

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