Ultrasonic testing methods, systems, electronic devices, storage media, and software products

Abstract

This disclosure provides an ultrasonic testing method, system, electronic device, storage medium, and program product. The ultrasonic testing method includes: applying a pulse drive signal to an under-display ultrasonic sensor to drive the under-display ultrasonic sensor to emit ultrasonic signals upwards towards the display screen. The display screen includes a screen cover plate, and the operating frequency f0 of the pulse drive signal deviates from the resonant frequency f of the screen cover plate. CG The operating frequency f0 of the pulse drive signal is selected to maximize the ultrasonic echo signal or maximize the signal-to-noise ratio of the ultrasonic echo signal. The ultrasonic echo signal is the ultrasonic signal reflected by the unit under test above the display screen and received by the under-screen ultrasonic sensor. Feature detection is performed based on the ultrasonic echo signal to identify the unit under test above the display screen. The technical solution of this disclosure embodiment can improve the performance of ultrasonic detection.

Description

Technical Field

[0001] This disclosure relates to the field of ultrasonic testing technology, and more particularly to an ultrasonic testing method, system, electronic device, storage medium, and program product. Background Technology

[0002] Under-display ultrasonic testing systems are increasingly being used in electronic devices. These systems utilize under-display ultrasonic sensors to perform ultrasonic testing, and the specific modules within each system determine the testing capabilities. For example, under-display ultrasonic fingerprint sensors can detect fingerprints using ultrasonic signals. However, the performance of current under-display ultrasonic testing methods still needs improvement. Summary of the Invention

[0003] In view of the above, embodiments of this disclosure provide an ultrasonic testing method, system, electronic device, storage medium, and program product to at least partially solve the above problems.

[0004] According to a first aspect of the present disclosure, an ultrasonic detection method is provided, comprising:

[0005] A pulse drive signal is applied to the under-display ultrasonic sensor to drive the sensor to emit ultrasonic signals upwards toward the display screen, wherein the display screen includes a screen cover, and the operating frequency f0 of the pulse drive signal deviates from the resonant frequency f of the screen cover. CG The operating frequency f0 of the pulse drive signal is selected to make the ultrasonic echo signal the strongest or the ultrasonic echo signal the highest signal-to-noise ratio. The ultrasonic echo signal is the ultrasonic signal reflected by the detection unit above the display screen and received by the under-screen ultrasonic sensor. The step of applying the pulse drive signal to the under-screen ultrasonic sensor includes: generating a control pulse signal through a pulse signal generation unit and processing the control pulse signal through a resonant unit to obtain a pulse drive signal, so as to apply the pulse drive signal to the under-screen ultrasonic sensor.

[0006] Feature detection is performed based on the ultrasonic echo signal to identify the unit to be detected above the display screen.

[0007] According to a second aspect of the present disclosure, an ultrasonic detection system is provided, comprising: a driving module, an under-display ultrasonic sensor, a display screen, and a detection module, wherein the display screen includes a screen cover.

[0008] The driving module includes a pulse signal generation unit and a resonant unit. The driving module is used to: generate a control pulse signal through the pulse signal generation unit, and process the control pulse signal through the resonant unit to obtain a pulse driving signal, so as to apply the pulse driving signal to the under-display ultrasonic sensor to drive the under-display ultrasonic sensor to emit ultrasonic signals upwards towards the display screen; the operating frequency f0 of the pulse driving signal deviates from the resonant frequency f of the screen cover. CG The operating frequency f0 of the pulse drive signal is selected to make the ultrasonic echo signal the strongest or the ultrasonic echo signal the highest signal-to-noise ratio. The ultrasonic echo signal is the ultrasonic signal that is reflected by the detection unit above the display screen and received by the ultrasonic sensor under the screen.

[0009] The detection module is used to perform feature detection based on the ultrasonic echo signal to identify the unit to be detected above the display screen.

[0010] According to a third aspect of the present disclosure, an electronic device is provided, comprising: an ultrasonic detection system as described in the second aspect.

[0011] According to a fourth aspect of the present disclosure, a computer storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method as described in any one of the first aspects.

[0012] According to a fifth aspect of the present disclosure, a computer program product is provided, comprising a computer program that, when executed by a processor, implements the method as described in any one of the first aspects.

[0013] The ultrasonic detection method in this embodiment can apply a pulse drive signal to an under-display ultrasonic sensor to drive the under-display ultrasonic sensor to emit ultrasonic signals upwards towards the display screen. The operating frequency f0 of the pulse drive signal deviates from the resonant frequency f of the screen cover plate of the display screen. CGFurthermore, the operating frequency f0 of the pulse drive signal is selected to maximize the ultrasonic echo signal or maximize its signal-to-noise ratio. The ultrasonic echo signal is the ultrasonic signal reflected by the unit under the display screen and received by the ultrasonic sensor under the screen. Therefore, this solution can select a high-performance operating frequency of the pulse drive signal to ensure the quality of the ultrasonic echo signal. In addition, in this embodiment, a control pulse signal can be generated by a pulse signal generation unit, and a pulse drive signal can be obtained by processing the control pulse signal through a resonant unit. The pulse drive signal is then applied to the ultrasonic sensor under the screen, thereby effectively realizing the generation, application, and selection of the operating frequency of the pulse drive signal. Moreover, in this embodiment, feature detection is performed based on the high-quality ultrasonic echo signal obtained above, which facilitates accurate identification of the unit under the display screen, effectively improves the clarity of ultrasonic detection imaging, and enhances the ultrasonic detection effect and performance. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings.

[0015] Figure 1 A schematic diagram of an ultrasonic testing system, representing some examples of embodiments of this disclosure, is shown.

[0016] Figure 2A Schematic diagrams of a driving module, an under-display ultrasonic sensor, and a display screen are shown for some examples of embodiments of this disclosure.

[0017] Figure 2B Schematic diagrams of a driving module, an under-display ultrasonic sensor, and a display screen are shown in some other examples of embodiments of this disclosure.

[0018] Figure 3A A simplified schematic diagram of the acoustic-electric signal transmission of an optional ultrasonic testing system is shown.

[0019] Figure 3B A simplified schematic diagram of the acoustic-electric signal transmission of another optional ultrasonic detection system is shown.

[0020] Figure 4A A schematic diagram showing the spectrum of the control pulse signal, the frequency response of the resonant unit, and the spectrum of the pulse drive signal is shown.

[0021] Figure 4BThe spectrum of the control pulse signal, the frequency response of the resonant unit, and the spectrum of the pulse drive signal are shown in the example.

[0022] Figure 5 The frequency response of an example under-screen ultrasonic sensor is shown.

[0023] Figure 6A The frequency response of an example display body is shown.

[0024] Figure 6B The frequency response of an example screen cover is shown.

[0025] Figure 7 The frequency response of an example receiving module is shown.

[0026] Figure 8 The spectrum of the ultrasonic signal received by the under-screen ultrasonic sensor is shown when the sample unit to be tested is not pressed and when it is pressed above the display screen.

[0027] Figure 9 A flowchart of an ultrasonic testing method, representing some examples of embodiments of this disclosure, is shown.

[0028] Figure 10 Schematic diagrams of some examples of electronic devices in embodiments of this disclosure are shown.

[0029] Explanation of reference numerals in the attached figures:

[0030] 100. Ultrasonic testing system; 102. Drive module; 1022. Pulse signal generation unit; 1024. Resonance unit; 104. Under-screen ultrasonic sensor; 106. Display screen; 1062. Display screen body; 1064. Screen cover; 1066. Screen film; 108. Detection module; 110. Receiving module; 200. Unit to be tested; 300. Electronic equipment. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions in the embodiments of this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and thoroughly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art should fall within the protection scope of this disclosure.

[0032] Under-display ultrasonic testing systems are increasingly being used in electronic devices. These systems utilize under-display ultrasonic sensors to perform ultrasonic testing, and the specific modules within each system determine the testing capabilities. For example, under-display ultrasonic fingerprint sensors can detect fingerprints using ultrasonic signals. However, the performance of current under-display ultrasonic testing methods still needs improvement.

[0033] To facilitate the explanation of the technical solutions of the embodiments of this disclosure, the ultrasonic detection system in the embodiments of this disclosure will be introduced first.

[0034] This disclosure provides several ultrasonic detection systems 100, with reference to... Figure 1 As shown, the ultrasonic testing system 100 includes: a drive module 102, an under-display ultrasonic sensor 104, a display screen 106, and a detection module 108. The display screen 106 includes a screen cover 1064. Wherein, as... Figure 1 As shown, the driving module 102 includes a pulse signal generation unit 1022 and a resonant unit 1024. The driving module 102 is used to: generate a control pulse signal through the pulse signal generation unit 1022, and process the control pulse signal through the resonant unit 1024 to obtain a pulse driving signal, so as to apply the pulse driving signal to the under-display ultrasonic sensor 104 to drive the under-display ultrasonic sensor 104 to emit ultrasonic signals towards the top of the display screen 106; the operating frequency f0 of the pulse driving signal deviates from the resonant frequency f of the screen cover plate 1064. CG The operating frequency f0 of the pulse drive signal is selected to make the ultrasonic echo signal the strongest or the ultrasonic echo signal the highest signal-to-noise ratio. The ultrasonic echo signal is the ultrasonic signal received by the ultrasonic sensor 104 under the screen after the ultrasonic signal is reflected by the unit to be detected 200 above the display screen 106. The detection module 108 is used to perform feature detection based on the ultrasonic echo signal to identify the unit to be detected 200 above the display screen 106.

[0035] The ultrasonic detection system 100 in this embodiment can have its driving module 102 apply a pulse driving signal to the under-display ultrasonic sensor 104 to drive the under-display ultrasonic sensor 104 to emit ultrasonic signals above the display screen 106. The operating frequency f0 of the pulse driving signal deviates from the resonant frequency f of the screen cover plate 1064 of the display screen 106. CGFurthermore, the operating frequency f0 of the pulse drive signal is selected to maximize the ultrasonic echo signal or maximize the signal-to-noise ratio of the ultrasonic echo signal. The ultrasonic echo signal is the ultrasonic signal reflected by the unit under test 200 above the display screen 106 and received by the ultrasonic sensor 104 under the screen. Therefore, this solution can select a high-performance pulse drive signal operating frequency to ensure the quality of the ultrasonic echo signal. In addition, the drive module 102 can generate a control pulse signal through its pulse signal generation unit 1022 and process the control pulse signal through its resonant unit 1024 to obtain a pulse drive signal, which is then applied to the ultrasonic sensor 104 under the screen. This effectively realizes the generation, application, and selection of the operating frequency of the pulse drive signal. Moreover, the detection module 108 performs feature detection based on the high-quality ultrasonic echo signal obtained above, which facilitates accurate identification of the unit under test above the display screen, effectively improves the clarity of ultrasonic detection imaging, effectively improves the ultrasonic detection effect, and improves the ultrasonic detection performance.

[0036] The ultrasonic detection system 100 in this embodiment can be any type of ultrasonic detection system to achieve the corresponding ultrasonic feature detection function. In some optional embodiments, the under-display ultrasonic sensor 104 is an under-display ultrasonic fingerprint sensor, and the feature detection that can be achieved is fingerprint feature detection. That is, the ultrasonic detection system 100 can be an ultrasonic fingerprint detection system. Therefore, it is convenient to implement under-display fingerprint detection, improve the clarity of the ultrasonic fingerprint image, and improve the fingerprint detection effect and performance.

[0037] Optionally, the detection unit 200 above the display screen can be any fingerprint carrier, including but not limited to a finger (which can be combined with...). Figure 2A , Figure 2B (For example, to understand), physical models of fingerprints or fingers, etc.

[0038] The structure of each module of the ultrasonic testing system 100 is not specifically limited in this embodiment. As an example, Figure 2A Schematic diagrams of the driver module 102, the under-display ultrasonic sensor 104, and the display screen 106 are shown in some examples. Figure 2B Schematic diagrams of other examples of the drive module 102, the under-display ultrasonic sensor 104, and the display screen 106 are shown. Figure 2A and Figure 2B The examples can all be part of the ultrasonic testing system 100, and the testing module 108 is omitted. It is understandable that... Figure 2A and Figure 2B The difference between the examples is that, Figure 2A The display screen 106 includes a screen film 1066, and Figure 2BThe display screen 106 has no screen protector. Figure 2A and Figure 2B This is not intended to limit the technical solutions of the embodiments of this disclosure, but is only used to facilitate understanding of the embodiments of this disclosure.

[0039] Optionally, the drive module 102 can apply a pulse drive signal to the under-display ultrasonic sensor 104. Optionally, as... Figure 2A , Figure 2B As shown, the driving module 102 may include a pulse signal generation unit 1022 and a resonant unit 1024. The pulse signal generation unit 1022 can be used to generate control pulse signals, which may include multiple pulses. Optionally, the pulse signal generation unit 1022 can be implemented as any feasible pulse signal transmitter. The resonant unit 1024 is electrically connected to the pulse signal generation unit 1022, and the resonant unit 1024 can process the control pulse signals generated by the pulse signal generation unit 1022 to obtain a pulse drive signal V. TX The pulse drive signal V can be transmitted through the resonant unit 1024. TX An ultrasonic sensor 104 is applied under the screen. The resonant unit 1024 can employ any suitable resonant circuit, such as a parallel resonant circuit, a series resonant circuit, etc. Optionally, such as... Figure 2A , Figure 2B In the example shown, the resonant unit 1024 may include an LC resonant circuit. Alternatively, as... Figure 2A , Figure 2B As shown, the resonant unit 1024 includes an inductor L, a capacitor C, and a resistor R. One end of the inductor L is electrically connected to the pulse signal generation unit 1022, and the other end of the inductor L is electrically connected to the first end of the resistor R. The second end of the resistor R is electrically connected to the first end of the capacitor C and the under-screen ultrasonic sensor 104. The second end of the capacitor C is grounded. The operating frequency of the control pulse signal generated by the pulse signal generation unit 1022 is f. CTRL Optionally, the control pulse signal can be input from the first terminal of the inductor L, and formed into a pulse drive signal through the first terminal of the capacitor C and applied to the under-screen ultrasonic sensor 104, so as to drive the under-screen ultrasonic sensor 104 to emit ultrasonic signals above the display screen 106.

[0040] Optionally, such as Figure 2A , Figure 2B As shown, the under-display ultrasonic sensor 104 can be bonded to the underside of the display screen 106 via an adhesive layer. The adhesive layer may or may not be part of the display screen 106; this example can be understood as the adhesive layer being part of the display screen 106. Optionally, as... Figure 2A , Figure 2BAs shown, the under-display ultrasonic sensor 104 may include an upper electrode, a piezoelectric layer, a lower electrode, and a substrate. The lower electrode and the substrate may be provided by an integrated circuit chip, which can arrange the circuit structure of the under-display ultrasonic sensor 104. The lower electrode is disposed on one side surface of the substrate, and the piezoelectric layer is disposed between the lower electrode and the upper electrode. Optionally, the upper electrode may be used to be subjected to an excitation signal (the excitation signal here may be the aforementioned pulse drive signal V). TX The piezoelectric layer is excited to emit ultrasonic signals. The lower electrode can be used to receive the returned ultrasonic echo signal. When the ultrasonic echo signal acts on the piezoelectric layer, an ultrasonic detection signal is generated between the upper and lower electrodes. The ultrasonic detection signal can be used to perform feature detection (e.g., fingerprint feature detection) on the unit 200 to be detected above the display screen 106. Optionally, the piezoelectric layer can generate ultrasonic signal emission and receive ultrasonic echo signal based on the piezoelectric effect (the piezoelectric material layer may include, but is not limited to, at least one of PVDF (polyvinylidene difluoride), lead zirconate titanate, and lithium niobate; the PVDF material may include PVDF, PVDF copolymers, etc.). Optionally, refer to Figure 2A , Figure 2B As shown, the lower electrode may include multiple electrodes arranged in an array, and these electrodes are grounded through multiple switches (such as switches K1, K2, K3, K4, K5, ..., Kn). When emitting an ultrasonic signal, the multiple switches K1~Kn are closed, causing the excitation signal (i.e., the pulse drive signal V) to be activated. TX An electric field is applied between the upper and lower electrodes to excite the piezoelectric layer to generate and emit ultrasonic signals.

[0041] Optionally, such as Figure 2A , Figure 2B As shown, the under-display ultrasonic sensor 104 may include pads, which can be connected to the upper electrode via upper electrode drive signal traces. The resonant unit 1024 of the drive module 102 can be electrically connected to the pads of the under-display ultrasonic sensor 104, thereby transmitting the pulse drive signal V. TX The upper electrode of the under-screen ultrasonic sensor 104 is applied. Optionally, as... Figure 2A , Figure 2B As shown, the under-display ultrasonic sensor 104 may also include a protective layer, which can be used to protect at least part of the structure of the under-display ultrasonic sensor 104 (such as the upper electrode), for example, to prevent water and oxygen corrosion.

[0042] Optionally, such as Figure 2A , Figure 2B As shown, the ultrasonic testing system 100 may further include a receiving module 110, which can be electrically connected to the testing module 108 (the testing module 108 is not connected to the receiving module 108). Figure 2A , Figure 2B (As shown in the diagram). Optionally, the detection module 108 can receive the ultrasonic detection signal generated by the ultrasonic echo signal through the receiving module 110, and then perform feature detection (e.g., fingerprint feature detection) based on the ultrasonic detection signal to identify the unit to be detected 200 above the display screen 106. The structure of the receiving module 110 is not specifically limited here. Optionally, the receiving module 110 may include a receiving amplifier, which can be electrically connected to the lower electrode of the under-display ultrasonic sensor 104, and can send the ultrasonic detection signal to the detection module 108.

[0043] Optionally, the detection module 108 can be implemented as any hardware with data processing capabilities, such as a processor, processing module, or processing chip. For example, the detection module 108 may include a processor independent of the under-display ultrasonic sensor 104 in an electronic device, or it may include a processor integrated within the under-display ultrasonic sensor 104. Optionally, the detection module 108 can process the ultrasonic detection signal to generate an image, and can perform feature detection based on the generated image. Optionally, taking under-display ultrasonic fingerprint feature detection as an example, the detection module 108 can generate a fingerprint image by processing the ultrasonic detection signal, and can perform fingerprint feature detection based on the fingerprint image.

[0044] Optionally, such as Figure 2A , Figure 2B As shown, the display screen 106 may include at least a display body 1062 and a screen cover 1064. Optionally, the display body 1062 can be understood as a combination of all layers between the screen cover 1064 and the under-display ultrasonic sensor 104. Optionally, as Figure 2A , Figure 2B As shown, the display body 1062 may include, but is not limited to, structures such as an adhesive layer, a backing layer, a display layer, a polarizer, and an OCA (Optically Clear Adhesive) layer. The adhesive layer can bond the under-display ultrasonic sensor 104 to the backing layer of the display body 1062; for example, the adhesive layer can be bonded to the substrate of the under-display ultrasonic sensor 104. The OCA adhesive layer can bond the display body 1062 to the screen cover 1064. The structures in the display body 1062 can be understood in conjunction with relevant technologies, and will not be elaborated further here. The screen cover 1064 can be used to protect the display body 1062, serving as a protective cover. The screen cover 1064 may include, but is not limited to, a glass cover, a plastic cover, an optical composite material cover, etc.

[0045] Optionally, such as Figure 2AAs shown, the display screen 106 may also include a screen film 1066, which may be a screen protector, including but not limited to tempered glass, soft film, PET (Polyethylene terephthalate) film, hydrogel film, etc. Figure 2A As shown, the unit to be detected 200 (such as a user's finger) can be placed above the screen film 1066 for feature detection. Optionally, as... Figure 2B As shown, the display screen 106 may also be without a screen film 1066, and the detection unit 200 (such as a user's finger) may be placed above the screen cover 1064 for feature detection.

[0046] It should be understood that the above introduction Figure 2A and Figure 2B The structural examples provided are merely optional examples. Other feasible structures for the drive module 102, under-display ultrasonic sensor 104, display screen 106, and receiver module 110 may also be used. No restrictions are imposed on these in this embodiment.

[0047] For example, here Figure 2A The example demonstrates signal analysis of an ultrasonic testing system. Figure 3A A simplified schematic diagram of the acoustic-electric signal transmission in an optional ultrasonic testing system is shown. The acoustic-electric signal of the ultrasonic testing system can be decomposed into... Figure 3A The components and their corresponding transfer functions are defined. Here, tf0 is the pulse drive signal V emitted by the drive module 102. TX The frequency spectrum; tf1 is the frequency response of the under-display ultrasonic sensor 104, tf2 is the frequency response of the display body 1062, tf3 is the frequency response of the screen cover 1064, tf4 is the frequency response of the screen film 1066, and tf5 is the frequency response of the receiving module 110. Among them, the driving module 102 transmits a pulse driving signal V. TX There is LC resonance, and the pulse drive signal V TX Its frequency characteristics (spectrum tf0) are related to the L and C of the resonant unit 1024 and the operating frequency (transmission frequency) of the control pulse signal of the pulse signal generation unit 1022; tf1~tf4 are determined by the physical stacking of their respective parts, and the stacking material and thickness of each part determine their respective ultrasonic transmission characteristics; the receiving module 110 may or may not have frequency selection characteristics, and may have a certain bandwidth.

[0048] For example, such as Figure 2A and Figure 3A As shown, the pulse signal generation unit 1022 of the drive module 102 emits signals at a working frequency of f. CTRLThe control pulse signal, which may include several pulses, passes through the resonant unit 1024 (LC resonant network) to generate and transmit a pulse drive signal V. TX The pulse drive signal V is applied to the under-screen ultrasonic sensor 104. TX The spectrum is tf0;

[0049] Pulse drive signal V TX During transmission, multiple switches K1, ..., Kn of the under-screen ultrasonic sensor 104 are closed, and the pulse drive signal V... TX When applied between the upper and lower electrodes, the piezoelectric layer is excited to generate an ultrasonic signal, the spectrum of which is... ;

[0050] The frequency response of the display body 1062 of the display screen 106 is tf2. After the ultrasonic signal is transmitted through it, its spectrum is as follows: ;

[0051] Similarly, after the ultrasonic signal is transmitted through the screen cover 1064, the spectrum is... ;

[0052] Similarly, after the ultrasonic signal is transmitted through the screen 1066, the spectrum is as follows: ;

[0053] If the unit to be detected 200 (e.g., a finger) reflects an ultrasonic signal, and assuming the reflectivity is rf, then the spectrum of the reflected ultrasonic signal is... ;

[0054] The reflected ultrasonic signal needs to pass through the screen film 1066, screen cover 1064, display body 1062, and under-screen ultrasonic sensor 104 again, with frequency responses of tf4, tf3, tf2, and tf1 respectively. The ultrasonic detection signal generated by the ultrasonic echo signal received by the under-screen ultrasonic sensor 104 reaches the receiving module 110, whose frequency response is tf5. Therefore, the spectrum of the ultrasonic detection signal received by the receiving module 110 is as follows: Then, the receiving module 110 can further transmit the ultrasonic detection signal to the detection module 108 to achieve feature detection.

[0055] Figure 3B A simplified schematic diagram of the acoustic-electric signal transmission of another optional ultrasonic testing system is shown. It should be understood that, with... Figure 2A Similarly, for Figure 2B In the case of the 106-inch display screen without a screen protector 1066, it can be broken down into: Figure 3B The various parts and their corresponding transfer functions are then determined according to the aforementioned... Figure 2A and Figure 3AThe signal analysis process requires removing the frequency response tf4 of the screen 1066, i.e., the spectrum of the ultrasonic echo signal reflected by the unit to be detected 200 (e.g., a finger) is... The spectrum of the ultrasonic detection signal received by the receiving module 110 is as follows: . Figure 3B Examples and Figure 3A The examples are similar, so I won't go into detail here.

[0056] Optionally, in this embodiment of the present disclosure, when measuring the frequency response of a certain structure (taking the under-display ultrasonic sensor 104 as an example), a predetermined broadband ultrasonic signal with a known spectrum can be applied to the structure, and then the output spectrum of the output signal of the structure can be measured. The frequency response of the structure can be obtained by dividing the output spectrum by the input spectrum.

[0057] In some alternative embodiments, such as Figure 2A As shown in Figure 2B, the driving module 102 may include a pulse signal generation unit 1022 and a resonant unit 1024. The pulse signal generation unit 1022 can generate a control pulse signal, and the resonant unit 1024 can process the control pulse signal to obtain a pulse driving signal V. TX The pulse drive signal V is transmitted through the resonant unit 1024. TX An ultrasonic sensor 104 is applied under the screen.

[0058] Optionally, the operating frequency f0 of the pulse drive signal and the operating frequency f of the control pulse signal are... CTRL The resonant frequency f of the resonant unit 1024 LC The following conditions must be met between them: f CTRL <f0<f LC .

[0059] Based on this, the operating frequency f0 of the pulse drive signal of the under-display ultrasonic sensor 104 in this embodiment is located at the operating frequency f of the control pulse signal generated by the pulse signal generation unit 1022. CTRL And the resonant frequency f of the resonant unit 1024 LC Between these, the operating frequency f of the control pulse signal can be adjusted. CTRL This allows the operating frequency f0 of the pulse drive signal to approach or equal the optimal operating frequency, facilitating the selection of a high-performance pulse drive signal frequency f0. This ensures the quality of the ultrasonic echo signal, improves the clarity of the ultrasonic detection image, and effectively enhances the ultrasonic detection effect and performance. The above-mentioned alternative solution is well-suited for both situations with and without a screen film, and the operating frequency f0 of the pulse signal can be adjusted and controlled. CTRL This allows the operating frequency f0 of the pulse drive signal to adapt to different scenarios.

[0060] In this embodiment, the operating frequency f0 of the pulse drive signal deviates from the resonant frequency f of the screen cover plate 1064. CG This allows for the selection of a high-performance pulse drive signal operating frequency to ensure the quality of the ultrasonic echo signal. If the operating frequency f0 of the pulse drive signal is equal to the resonant frequency f of the screen cover plate 1064... CG Because the influence of other layers was not taken into account, the imaging clarity of the ultrasonic detection was poor. In this embodiment, the operating frequency f0 is deviated from the resonant frequency f of the screen cover plate 1064. CG Taking into account the impact of multiple layers on the clarity of ultrasonic detection imaging, it can effectively improve the ultrasonic detection effect.

[0061] In some optional embodiments, the operating frequency f0 of the pulse drive signal and the resonant frequency f of the screen cover 1064 are... CG The following condition must be met: f0 < f CG This makes it easier to select a high-performance pulse drive signal operating frequency, ensuring the quality of the ultrasonic echo signal, effectively improving the clarity of ultrasonic detection imaging, and enhancing the ultrasonic detection effect and performance.

[0062] In some optional embodiments, the operating frequency f0 of the pulse drive signal, the resonant frequency f1 of the under-display ultrasonic sensor 104, and the resonant frequency f of the screen cover 1064 are all specified. CG The following conditions must be met: f0 < f1 < f CG This makes it easier to select a high-performance pulse drive signal operating frequency, ensuring the quality of the ultrasonic echo signal, effectively improving the clarity of ultrasonic detection imaging, and enhancing the ultrasonic detection effect and performance.

[0063] In some optional embodiments, the operating frequency f0 of the pulse drive signal, the resonant frequency f1 of the under-display ultrasonic sensor 104, and the resonant frequency f2 of the display screen 106 satisfy the following relationship: f0 < f1 < f2. This makes it easier to select a pulse drive signal with better performance, ensuring the quality of the ultrasonic echo signal, effectively improving the clarity of ultrasonic detection imaging, and thus improving the ultrasonic detection effect and performance.

[0064] In some alternative embodiments, the drive module 102 can change the operating frequency f of the control pulse signal through the pulse signal generation unit 1022. CTRL The operating frequency f0 of the pulse drive signal is dynamically adjusted.

[0065] Therefore, in this embodiment of the present disclosure, the pulse signal generation unit 1022 controls the operating frequency f of the control pulse signal.CTRL The adjustment can effectively achieve dynamic adjustment of the working frequency f0 of the pulse drive signal. In addition, it can adapt to the influence of different external environments (such as different temperatures) on the resonant frequencies of various parts of the ultrasonic testing system. This makes it easier to dynamically select the working frequency of the pulse drive signal with better performance, so as to ensure the quality of the ultrasonic echo signal, effectively improve the clarity of ultrasonic detection imaging, and effectively improve the ultrasonic detection effect and performance.

[0066] Below, refer to Figure 2A , Figure 2B The examples illustrate tf0~tf5 to facilitate understanding.

[0067] [I] Regarding the pulse drive signal V emitted by the drive module 102 TX The spectrum tf0. (Refer to...) Figure 2A , Figure 2B As shown, the driving module 102 may include a pulse signal generation unit 1022 and a resonant unit 1024, and the pulse driving signal V TX The frequency spectrum tf0 can be obtained by multiplying the frequency spectrum tf_CTRL of the control pulse signal and the frequency response tf_LC of the resonant unit 1024 (LC resonant network), i.e. .

[0068] Figure 4A The spectrum of the control pulse signal tf_CTRL is shown (in...) Figure 4A The vertical axis represents amplitude), and the frequency response tf_LC of the resonant unit 1024 (in) Figure 4A The vertical axis represents the gain and the pulse drive signal V. TX The spectrum tf0 (in Figure 4A A schematic diagram (with the vertical axis representing the amplitude), as shown below. Figure 4A As shown, its highest response frequency (which can also be understood as the optimal operating frequency) is located at the operating frequency f of the control pulse signal. CTRL The resonant frequency f of the resonant unit 1024 LC between.

[0069] Figure 4B The spectrum of the control pulse signal tf_CTRL in the example is shown. Figure 4B The vertical axis represents amplitude), and the frequency response tf_LC of the resonant unit 1024 (in) Figure 4B The vertical axis represents the gain and the pulse drive signal V. TX The spectrum tf0 (in Figure 4B The vertical axis represents the amplitude, from Figure 4B It can be seen that f LC =13MHz, f CTRL =10MHz, pulse drive signal VTX The highest response frequency (as indicated by the arrow) is between 10MHz and 13MHz, and slightly higher than 10MHz.

[0070] It should be understood that the pulse drive signal V TX The operating frequency f0 can be changed by adjusting the operating frequency of the control pulse signal V. TX The operating frequency f0 is located at the operating frequency f of the control pulse signal. CTRL And the resonant frequency f of the resonant unit 1024 LC Between these parameters, the operating frequency f0 of the pulse drive signal can be made close to or equal to the optimal operating frequency. Therefore, it is easier to select a pulse drive signal with better performance at its operating frequency f0, so as to ensure the quality of the ultrasonic echo signal, improve the clarity of ultrasonic detection imaging, and effectively improve the ultrasonic detection effect and performance.

[0071] It should be understood that the operating frequency f of the control pulse signal CTRL Depending on external input, adjustments and settings can be made as needed. In some alternative embodiments of this disclosure, f can be adjusted... CTRL By making reasonable settings to adjust and select f0, the aim is to better ensure the quality of ultrasonic echo signals, improve the clarity of ultrasonic detection imaging, enhance the ultrasonic detection effect, and improve the ultrasonic detection performance.

[0072] The resonant frequency f of the resonant unit 1024 LC Depending on the L and C values ​​of the resonant unit 1024, it can be determined using the formula... get.

[0073] [II] Regarding the frequency response tf1 of the under-display ultrasonic sensor 104. (Refer to...) Figure 2A , Figure 2B As shown, the under-display ultrasonic sensor 104 may include structures such as an upper electrode, a piezoelectric layer, a lower electrode, a substrate, and a protective layer. The lower electrode and the substrate may be provided by an integrated circuit chip. The frequency response tf1 of the under-display ultrasonic sensor 104 is determined by its stacked materials and thickness, and its resonant frequency can be obtained by computer simulation or actual measurement.

[0074] Figure 5 The frequency response tf1 of an example under-display ultrasonic sensor 104 is shown. In this example, the resonant frequency of the under-display ultrasonic sensor 104 is 11.6 MHz. Figure 5 As shown, the pulse drive signal V TX The spectrum tf0 (in Figure 5 The peak frequency (with amplitude as the vertical axis) and the frequency response tf1 of the under-display ultrasonic sensor 104 (in) Figure 5The peak frequencies of the ultrasonic signals emitted by the under-display ultrasonic sensor 104 (which can be emitted by the piezoelectric layer) cannot completely overlap. The frequency spectrum tf_csb of the ultrasonic signal emitted by the under-display ultrasonic sensor 104 (which can be emitted by the piezoelectric layer) is... Figure 5 The vertical axis represents amplitude, and its optimal frequency (as indicated by the arrow) is between the pulse drive signal V. TX The frequency spectrum tf0 and the peak frequency of the frequency response tf1 of the under-screen ultrasonic sensor 104 are related.

[0075]

III

[0076] Figure 6A The frequency response tf2 of the example display body 1062 is shown, such as Figure 6A As shown, the frequency response tf2 of the display body 1062 can have multiple peak points, with the resonant peak frequency being... N is a positive integer. The frequency response tf2 of the display body 1062 can generally be obtained through calculation-aided calculation, but the position of the peak frequency can also be obtained through the formula fm=500 / t_fly_total, where fm can be in MHz and t_fly_total is the time delay generated by the ultrasonic longitudinal wave passing through the display body, which is the cumulative sum of the ultrasonic delays of each layer in the display body, in ns. Optionally, when the under-display ultrasonic sensor 104 is an under-display ultrasonic fingerprint sensor, the frequency range of interest for ultrasonic fingerprinting can be 5MHz~25MHz.

[0077]

IV

[0078] [V] Regarding the frequency response tf4 of the screen film 1066. The frequency response tf4 of the screen film 1066 depends on the material and thickness of the screen film 1066. Generally speaking, the screen film 1066 also has a resonant frequency f for ultrasonic signals. prtf .

[0079]

VI

[0080] In some alternative embodiments, refer to Figure 2B As shown, the display screen 106 may include a display body 1062 and a screen cover 1064, with the display body 1062 located between the under-screen ultrasonic sensor 104 and the screen cover 1064; wherein, the resonant frequency f of the display body 1062 is... panel The resonant frequency f2 of the display screen 106 and the resonant frequency f of the screen cover 1064. CG The following conditions must be met between them: f panel <f2<f CG .

[0081] It should be understood that, under the above circumstances, the display screen 106 may be without a screen protector 1066.

[0082] Based on this, in this embodiment of the disclosure, when the display screen 106 includes a display screen body 1062 and a screen cover 1064, the resonant frequency f2 of the display screen 106 is between the resonant frequency f of the display screen body 1062 and the resonant frequency f of the display screen body 1062. panel The resonant frequency f of the 1064-inch screen cover CG This spacing helps ensure the quality of the ultrasonic echo signal, thereby improving the clarity of ultrasonic detection imaging and effectively enhancing the ultrasonic detection effect and performance.

[0083] In some optional embodiments, the display screen 106 further includes a display body 1062, which is located between the under-screen ultrasonic sensor 104 and the screen cover 1064; the operating frequency f of the control pulse signal is... CTRL Located between the first peak frequency and the second peak frequency, wherein the first peak frequency and the second peak frequency are two adjacent peak frequencies in the frequency response curve of the display body 1062 and the frequency response curve of the screen cover 1064, respectively, and the first peak frequency is less than the second peak frequency.

[0084] In this embodiment, the operating frequency f of the control pulse signal is... CTRL Adjusting the frequency to between the first and second peak frequencies facilitates the selection of a high-performance pulse drive signal operating frequency f0, ensuring the quality of the ultrasonic echo signal, improving the clarity of ultrasonic imaging, and effectively enhancing the ultrasonic detection effect and performance.

[0085] In some alternative embodiments, both the first peak frequency and the second peak frequency are in the range of 9MHz to 13MHz.

[0086] In this embodiment of the application, the operating frequency f of the control pulse signal is... CTRL Adjusting the frequency to the selectable range of 9MHz to 13MHz makes it easier to select the operating frequency f0 of the pulse drive signal with better performance. This is more suitable for the needs of ultrasonic fingerprint detection, ensuring the quality of the ultrasonic echo signal, improving the clarity of ultrasonic detection imaging (such as fingerprint images), effectively improving the ultrasonic detection effect (such as improving the fingerprint feature detection effect), and improving the ultrasonic detection performance (such as improving the fingerprint feature detection performance).

[0087] For example, refer to Figure 8 It shows the ultrasonic signal spectra of some examples of the unit to be detected (e.g., a finger) when it is not pressed and when it is pressed on the display screen. Figure 8 In the diagram, points a3 and a4 represent the 3rd and 4th resonant peak frequencies (3fm and 4fm) of the ultrasonic transmission spectrum tf2 of the display body 1062, and point b2 represents the 2nd resonant peak frequency of the ultrasonic transmission spectrum tf3 of the screen cover 1064. By dividing the spectrum of the ultrasonic signal received by the under-screen ultrasonic sensor 104 when the unit under test is not pressed onto the display screen (also referred to as the unpressed spectrum) by the spectrum of the ultrasonic signal received by the under-screen ultrasonic sensor 104 when the unit under test is pressed onto the display screen (also referred to as the pressed spectrum), the frequency point (peak frequency) corresponding to the highest gain in the resulting frequency response (unpressed spectrum / pressed spectrum) is the peak frequency. The optimal resonant frequency of display screen 106 is taken as its resonant frequency f2. Then, a3 is taken as the first peak frequency and b2 as the second peak frequency. It can be seen that a3 and b2 are two adjacent peak frequencies in the frequency response curves of display body 1062 and screen cover 1064, respectively (where a3 is the third peak frequency of the frequency response curve of display body 1062 and b2 is the second peak frequency of the frequency response curve of screen cover 1064). The first peak frequency is less than the second peak frequency, indicating that f2 lies between a3 (the first peak frequency) and b2 (the second peak frequency) and is closer to b2. Therefore, taking frequency a3 as f2... panelb2 frequency is f CG That is, f panel <f2<f CG Optionally, such as Figure 8 As shown, the ideal state at f2 is for the operating frequency f0 of the pulse drive signal to coincide with the resonant frequency f2 of the display screen 106, but this is difficult to achieve in practice. Therefore, f2 can be chosen as the optimal frequency. CTRL Deviating from f2, f CTRL Located between the first and second peak frequencies, this allows for the selection of a high-performance pulse drive signal operating frequency f0. It should be understood that... Figure 8 The examples provided are not intended to limit any aspect of the embodiments disclosed herein.

[0088] In some alternative embodiments, the operating frequency f of the control pulse signal is... CTRL The deviation from the third peak frequency, wherein the third peak frequency is the peak frequency in the ratio of the spectrum of the first echo signal to the spectrum of the second echo signal, wherein the first echo signal is the ultrasonic signal received by the under-screen ultrasonic sensor 104 when the unit under test 200 is not placed above the display screen 106, and the second echo signal is the ultrasonic signal received by the under-screen ultrasonic sensor 104 when the unit under test is placed above the display screen 106.

[0089] In this embodiment, the operating frequency f of the control pulse signal is... CTRL Adjusting the frequency to deviate from the third peak frequency makes it easier to select a better-performing pulse drive signal operating frequency f0, ensuring the quality of the ultrasonic echo signal, improving the clarity of ultrasonic detection imaging, and effectively enhancing the ultrasonic detection effect and performance.

[0090] In some alternative embodiments, the operating frequency f of the control pulse signal is... CTRL The peak frequency is less than the third peak frequency and greater than the fourth peak frequency, wherein the fourth peak frequency is the peak frequency in the spectrum of the first echo signal and / or the spectrum of the second echo signal that is closest to the third peak frequency and less than the third peak frequency.

[0091] In this embodiment, the operating frequency f of the control pulse signal is... CTRL Adjusting the frequency to be lower than the third peak frequency and higher than the fourth peak frequency makes it easier to select a better-performing pulse drive signal operating frequency f0, ensuring the quality of the ultrasonic echo signal, improving the clarity of ultrasonic detection imaging, and effectively enhancing the ultrasonic detection effect and performance.

[0092] For example, corresponding to the above Figure 8To understand this using an example, the first echo signal is the ultrasonic signal received by the under-screen ultrasonic sensor 104 when the unit to be detected is not pressed on the display screen, and the second echo signal is the ultrasonic signal received by the under-screen ultrasonic sensor 104 when the unit to be detected is pressed on the display screen. Correspondingly, the spectrum of the first echo signal is... Figure 8 The spectrum of the unpressed signal, and the spectrum of the second echo signal, are also... Figure 8 The pressed spectrum. The ratio of the spectrum of the first echo signal to the spectrum of the second echo signal, i.e., the frequency response obtained by dividing the unpressed spectrum by the pressed spectrum. The third peak frequency is also the peak frequency in the frequency response obtained by dividing the unpressed spectrum by the pressed spectrum. The peak frequency c, which is closest to but less than the third peak frequency in the spectra of the first and second echo signals, is... Figure 8 The frequencies overlap, therefore the fourth peak frequency is c (e.g., Figure 8 As shown in the example, c can be less than 11MHz. As explained above, the frequency point corresponding to the highest gain in the frequency response obtained by the unpressed spectrum / pressed spectrum (i.e., the ratio of the spectrum of the first echo signal to the spectrum of the second echo signal) is the optimal resonant frequency of the display screen 106. Taking it as the resonant frequency f2 of the display screen 106, since the ideal state at f2 is for the operating frequency f0 of the pulse drive signal to coincide with the resonant frequency f2 of the display screen 106, but this is difficult to achieve in practice, f can be chosen as the optimal frequency. CTRL Deviating from f2 (which is also the third peak frequency), such as Figure 8 As shown, f CTRL It can be less than the third peak frequency, and f CTRL It can be greater than the fourth peak frequency, f CTRL Located between the first and second peak frequencies, this allows for the selection of a high-performance pulse drive signal operating frequency f0. It should be understood that... Figure 8 The examples provided are not intended to limit any aspect of the embodiments disclosed herein.

[0093] In some alternative embodiments, refer to Figure 2A As shown, the display screen 106 may include a display body 1062, a screen cover 1064, and a screen film 1066. The display body 1062 is located between the under-screen ultrasonic sensor 104 and the screen cover 1064, and the screen cover 1064 is located between the display body 1062 and the screen film 1066. The resonant frequency f of the display body 1062 is... panel The resonant frequency f2 of the display screen 106 and the resonant frequency f of the screen cover 1064. CG The resonant frequency f of the 1066 screen film prtf The following conditions must be met between them: f display <f2<f prtf, where f panel <f display <f CG .

[0094] It should be understood that, in the above-described scenario, the display screen 106 may include a screen film 1066. In the above-described scenario, f display This can be considered as the resonant frequency of the stacked layers of the display body 1062 and the screen cover 1064, which is similar to the aforementioned Figure 2B Similar to f2 in the example, between f panel and f CG between.

[0095] Based on this, in this embodiment of the disclosure, when the display screen 106 includes a display screen body 1062, a screen cover 1064, and a screen film 1066, the resonant frequency f2 of the display screen 106 is intermediate with the resonant frequency f of the stacked layers of the display screen body 1062 and the screen cover 1064. display The resonant frequency f of the 1066 screen film prtf This spacing helps ensure the quality of the ultrasonic echo signal, thereby improving the clarity of ultrasonic detection imaging and effectively enhancing the ultrasonic detection effect and performance.

[0096] In some alternative embodiments, the operating frequency f of the control pulse signal is... CTRL The resonant frequency f1 of the under-display ultrasonic sensor 104 and the resonant frequency f2 of the display screen 106 satisfy the following relationship: , where 0.01≤α≤2.

[0097] Based on this, in the embodiments of this disclosure, the operating frequency f of the control pulse signal is adjusted and set. CTRL to And 0.01≤α≤2, which allows f1 and f CTRL The small deviation between f2 and f3 facilitates the pulse drive signal V. TX The operating frequency f0, the resonant frequency f1 of the under-screen ultrasonic sensor 104, and the resonant frequency f2 of the display screen 106 have small deviations, which makes it easier to select the operating frequency f0 of the pulse drive signal with better performance. This facilitates the selection to achieve the strongest ultrasonic echo signal or the highest signal-to-noise ratio of the ultrasonic echo signal, which helps to ensure the quality of the ultrasonic echo signal, thereby improving the clarity of ultrasonic detection imaging and effectively improving the ultrasonic detection effect and performance.

[0098] In the above optional embodiments, α can be called the deviation coefficient. Within the range of 0.01 ≤ α ≤ 2, α can be selected as needed. For example, α can take values ​​of 0.01, 0.03, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, etc.

[0099] In some optional embodiments, 0.01 ≤ α ≤ 0.5. Therefore, within this optional range, α can better ensure that f1 and f... CTRL The small deviation between f2 and f3 facilitates the pulse drive signal V. TX The operating frequency f0, the resonant frequency f1 of the under-screen ultrasonic sensor 104, and the resonant frequency f2 of the display screen 106 are relatively close to each other, which makes it easier to select the operating frequency f0 of the pulse drive signal with better performance. This helps to ensure the quality of the ultrasonic echo signal, thereby improving the clarity of ultrasonic detection imaging and effectively improving the ultrasonic detection effect and performance.

[0100] Within the range of 0.01 ≤ α ≤ 0.5, α can be chosen as needed. For example, α can take values ​​of 0.01, 0.03, 0.05, 0.08, 0.1, 0.11, 0.13, 0.15, 0.18, 0.2, 0.21, 0.23, 0.25, 0.28, 0.3, 0.31, 0.33, 0.35, 0.38, 0.4, 0.41, 0.43, 0.45, 0.48, 0.5, etc.

[0101] Optionally, f is set in the embodiments of this disclosure. CTRL It may not be equal to f CG f panel f1, f LC Any one of them.

[0102] To improve ultrasonic testing performance, the resonant frequency f of the resonant unit 1024 can be selected. LC The frequency f2, which is close to the resonant frequency of the display screen 106, facilitates the pulse drive signal V. TX The small deviation between the operating frequency f0, the resonant frequency f1 of the under-screen ultrasonic sensor 104, and the resonant frequency f2 of the display screen 106 enhances the ultrasonic echo signal, thereby improving the clarity of ultrasonic detection imaging and effectively improving the ultrasonic detection effect.

[0103] In some alternative embodiments, the resonant frequency f of the resonant unit 1024 LC The range can be 0.75f² to 1.25f². That is, f can be selected... LCThis ranges from 25% above to below f2. For example, for display screen 106, f2 can be a known quantity, and can be determined by selecting appropriate L and C values ​​for the resonant unit 1024, according to the aforementioned formula. The resonant frequency f of the resonant unit 1024 LC Adjust to 0.75f2~1.25f2.

[0104] It should be understood that f LC Within the above-mentioned selectable range, it is convenient to make the pulse drive signal V TX The operating frequency f0, the resonant frequency f1 of the under-screen ultrasonic sensor 104, and the resonant frequency f2 of the display screen 106 are relatively close to each other, which makes it easier to select the operating frequency f0 of the pulse drive signal with better performance. This helps to ensure the quality of the ultrasonic echo signal, thereby improving the clarity of ultrasonic detection imaging and effectively improving the ultrasonic detection effect and performance.

[0105] Within the range of 0.75f² to 1.25f², f LC You can choose according to your needs. For example, f LC It can be 0.75f2, 0.8f2, 0.85f2, 0.9f2, 0.95f2, 1.0f2, 1.05f2, 1.1f2, 1.15f2, 1.2f2, 1.25f2, etc.

[0106] In some optional embodiments, the receiving module 110 can receive an ultrasonic detection signal generated by the ultrasonic echo signal, and the detection module 108 can perform feature detection based on the ultrasonic detection signal received by the receiving module 110 to identify the unit to be detected above the display screen 106. This allows for accurate and efficient feature detection and accurate identification of the unit to be detected above the display screen 106. For example, the feature detection can be fingerprint feature detection.

[0107] Optionally, the resonant frequency f of the receiving module 110 RX It may not be equal to the operating frequency f of the control pulse signal. CTRL This allows for more flexible setting of the operating frequency of the control pulse signal, enabling the selection of the operating frequency f0 of the pulse drive signal to achieve a better performance and thus realize convenient and efficient ultrasonic feature detection.

[0108] Alternatively, in other embodiments, the resonant frequency f of the receiving module 110 RX It can also be equal to the operating frequency f of the control pulse signal. CTRL As long as it meets the requirements, that's fine.

[0109] Optionally, the operating frequency f of the receiving module 110RX This can be equal to the ultrasonic transmission frequency f2 of the display screen 106. For the receiver module 110 with frequency selectivity, its resonant frequency f2 is... RX Setting the ultrasonic transmission frequency f2 to be equal to that of the display screen 106 can make the receiving module 110 receive signals more effectively, thereby improving the clarity of ultrasonic detection imaging, effectively improving the ultrasonic detection effect, improving the ultrasonic detection performance, and more accurately identifying the unit to be detected above the display screen.

[0110] The following description uses some optional examples to illustrate the above-mentioned optional embodiments:

[0111] [Optional Example 1]

[0112] For example, in some optional examples, display 106 has no screen film 1066 (see reference). Figure 2B (As illustrated in the example), and since the frequency response tf5 of the receiving module 110 has no obvious resonant frequency peak, meaning the receiving module 110 has no frequency selectivity, then tf5 = 1. In this case, the spectrum of the received ultrasonic detection signal is... (This can be understood in conjunction with the preceding text) The display screen 106 is defined as the display screen body 1062 + screen cover 1064.

[0113] Therefore, for the display screen 106 to operate at its optimal frequency, the resonant frequency f2 of the display screen 106 must satisfy f panel <f2<f CG (This can be understood in conjunction with the preceding text.)

[0114] Ideally, the best approach is to ensure that the resonant frequency f1 of the under-display ultrasonic sensor 104 and the operating frequency f of the control pulse signal are both within the optimal range. CTRL The resonant frequency f2 of display screen 106, the three are equal, that is, f1 = f CTRL =f2.

[0115] However, the under-display ultrasonic sensor 104 in actual production has discreteness, making it impossible to achieve f1=f2. Therefore, in order to achieve better performance, in the optional embodiment of this disclosure, the operating frequency f of the control pulse signal can be adjusted. CTRL Make appropriate adjustments and settings to facilitate adjusting the frequency f0 of the pulse drive signal.

[0116] For example, for the under-display ultrasonic sensor 104 and the display screen 106, f1 and f2 can both be known, and we can denote f1-f2=Δf. Then, according to " "To adjust f" CTRL Where α is the deviation coefficient, 0.01≤α≤2, preferably 0.01≤α≤0.5.

[0117] When selecting the resonant unit 1024, the L and C values ​​of the resonant unit 1024 can also be selected so that its resonant frequency f LC Adjust it to be close to f2, such as setting f. LC The range is from 0.75f2 to 1.25f2.

[0118] For f CTRL With proper adjustments and settings, f1 and f2 can be optimized. CTRL The small deviation between f2 and f3 facilitates the pulse drive signal V. TX The operating frequency f0, the resonant frequency f1 of the under-display ultrasonic sensor 104, and the resonant frequency f2 of the display screen 106 have small deviations, making it easier to select a high-performance pulse drive signal operating frequency f0. This facilitates the selection of a frequency that maximizes the ultrasonic echo signal or achieves the highest signal-to-noise ratio, ensuring the quality of the ultrasonic echo signal and improving the clarity of the ultrasonic detection imaging. This effectively enhances the ultrasonic detection effect and performance. Based on the obtained high-quality ultrasonic echo signal, feature detection is performed, facilitating accurate identification of the unit to be detected above the display screen.

[0119] Normally, the resonant frequency f of the receiving module 110 RX It may not be equal to the operating frequency f of the control pulse signal. CTRL .

[0120] [Optional Example 2]

[0121] For example, in some alternative examples, the display 106 includes a screen film 1066 (see reference). Figure 2A (As illustrated in the example), and since the frequency response tf5 of the receiving module 110 has no obvious resonant frequency peak, meaning the receiving module 110 has no frequency selectivity, then tf5 = 1. In this case, the spectrum of the received ultrasonic detection signal is... (This can be understood in conjunction with the preceding text) The display screen 106 is defined as the display body 1062 + screen cover 1064 + screen film 1066.

[0122] Therefore, for the display screen 106 to operate at its optimal frequency, the resonant frequency f2 of the display screen 106 must satisfy f display <f2<f prtf , where f panel <f display <f CG (This can be understood in conjunction with the preceding text.)

[0123] Ideally, the best approach is to ensure that the resonant frequency f1 of the under-display ultrasonic sensor 104 and the operating frequency f of the control pulse signal are both within the optimal range. CTRLThe resonant frequency f2 of display screen 106, the three are equal, that is, f1 = f CTRL =f2.

[0124] However, the under-display ultrasonic sensor 104 in actual production has discreteness, making it impossible to achieve f1=f2. Therefore, in order to achieve better performance, in the optional embodiment of this disclosure, the operating frequency f of the control pulse signal can be adjusted. CTRL Make appropriate adjustments and settings to facilitate adjusting the frequency f0 of the pulse drive signal.

[0125] For example, for the under-display ultrasonic sensor 104 and the display screen 106, f1 and f2 can both be known, and we can denote f1-f2=Δf. Then, according to " "To adjust f" CTRL Where α is the deviation coefficient, 0.01≤α≤2, preferably 0.01≤α≤0.5.

[0126] When selecting the resonant unit 1024, the L and C values ​​of the resonant unit 1024 can also be selected so that its resonant frequency f LC Adjust it to be close to f2, such as setting f. LC The range is from 0.75f2 to 1.25f2.

[0127] For f CTRL With proper adjustments and settings, f1 and f2 can be optimized. CTRL The small deviation between f2 and f3 facilitates the pulse drive signal V. TX The operating frequency f0, the resonant frequency f1 of the under-display ultrasonic sensor 104, and the resonant frequency f2 of the display screen 106 have small deviations, making it easier to select a high-performance pulse drive signal operating frequency f0. This facilitates the selection of a frequency that maximizes the ultrasonic echo signal or achieves the highest signal-to-noise ratio, ensuring the quality of the ultrasonic echo signal and improving the clarity of the ultrasonic detection imaging. This effectively enhances the ultrasonic detection effect and performance. Based on the obtained high-quality ultrasonic echo signal, feature detection is performed, facilitating accurate identification of the unit to be detected above the display screen.

[0128] Normally, the resonant frequency f of the receiving module 110 RX It may not be equal to the operating frequency f of the control pulse signal. CTRL .

[0129] [Optional Example 3]

[0130] For example, in some alternative examples, the display 106 includes a screen film 1066 (see reference). Figure 2A(As illustrated in the example), and the receiving module 110 may have frequency selectivity, then the spectrum of the received ultrasonic detection signal is as follows: The display screen 106 is defined as display screen body 1062 + screen cover plate 1064 + screen film 1066.

[0131] Therefore, for the display screen 106 to operate at its optimal frequency, the resonant frequency f2 of the display screen 106 must satisfy f display <f2<f prtf , where f panel <f display <f CG (This can be understood in conjunction with the preceding text.)

[0132] Ideally, the best approach is to ensure that the resonant frequency f1 of the under-display ultrasonic sensor 104 and the operating frequency f of the control pulse signal are both within the optimal range. CTRL The resonant frequency f2 of display screen 106, the three are equal, that is, f1 = f CTRL =f2.

[0133] However, the under-display ultrasonic sensor 104 in actual production has discreteness, making it impossible to achieve f1=f2. Therefore, in order to achieve better performance, in the optional embodiment of this disclosure, the operating frequency f of the control pulse signal can be adjusted. CTRL Make appropriate adjustments and settings to facilitate adjusting the frequency f0 of the pulse drive signal.

[0134] For example, for the under-display ultrasonic sensor 104 and the display screen 106, f1 and f2 can both be known, and we can denote f1-f2=Δf. Then, according to " "To adjust f" CTRL Where α is the deviation coefficient, 0.01≤α≤2, preferably 0.01≤α≤0.5.

[0135] When selecting the resonant unit 1024, the L and C values ​​of the resonant unit 1024 can also be selected so that its resonant frequency f LC Adjust it to be close to f2, such as setting f. LC The range is from 0.75f2 to 1.25f2.

[0136] This applies to f CTRL Adjustments and settings can be made to enable f1, f CTRL The small deviation between f2 and f3 facilitates the pulse drive signal V. TXThe operating frequency f0, the resonant frequency f1 of the under-display ultrasonic sensor 104, and the resonant frequency f2 of the display screen 106 have small deviations, making it easier to select a high-performance pulse drive signal operating frequency f0. This facilitates the selection of a frequency that maximizes the ultrasonic echo signal or achieves the highest signal-to-noise ratio, ensuring the quality of the ultrasonic echo signal and improving the clarity of the ultrasonic detection imaging. This effectively enhances the ultrasonic detection effect and performance. Based on the obtained high-quality ultrasonic echo signal, feature detection is performed, facilitating accurate identification of the unit to be detected above the display screen.

[0137] Normally, the resonant frequency f of the receiving module 110 RX It may not be equal to the operating frequency f of the control pulse signal. CTRL To enhance the signal reception capability of the frequency-selective receiver module 110, the resonant frequency f of the receiver module 110 can be set. RX It is equal to the ultrasonic transmission frequency f2 of the display screen 106.

[0138] It should be understood that the above optional examples are only used to facilitate understanding of the technical solutions of the embodiments of this disclosure, and are not intended to limit the embodiments of this disclosure in any way.

[0139] In summary, the ultrasonic detection system 100 in this embodiment can have its driving module 102 apply a pulse driving signal to the under-display ultrasonic sensor 104 to drive the under-display ultrasonic sensor 104 to emit ultrasonic signals towards the top of the display screen 106. The operating frequency f0 of the pulse driving signal deviates from the resonant frequency f of the screen cover plate of the display screen. CG Furthermore, the operating frequency f0 of the pulse drive signal is selected to maximize the ultrasonic echo signal or maximize the signal-to-noise ratio of the ultrasonic echo signal. The ultrasonic echo signal is the ultrasonic signal reflected by the unit under the display screen and received by the ultrasonic sensor under the screen. Therefore, this solution can select a high-performance pulse drive signal operating frequency to ensure the quality of the ultrasonic echo signal. In addition, the drive module 102 can generate a control pulse signal through its pulse signal generation unit 1022 and process the control pulse signal through its resonant unit 1024 to obtain a pulse drive signal, which is then applied to the ultrasonic sensor under the screen 104. This effectively realizes the generation, application, and selection of the operating frequency of the pulse drive signal. Moreover, the detection module 108 performs feature detection based on the high-quality ultrasonic echo signal obtained above, which facilitates accurate identification of the unit under the display screen, effectively improves the clarity of ultrasonic detection imaging, effectively improves the ultrasonic detection effect, and improves the ultrasonic detection performance.

[0140] Reference Figure 9 The flowchart shown in this disclosure also provides an ultrasonic testing method, which includes the following steps S102-S104, specifically:

[0141] S102: Apply a pulse drive signal to the under-screen ultrasonic sensor to drive the under-screen ultrasonic sensor to emit ultrasonic signals toward the top of the display screen.

[0142] The display screen includes a screen cover, and the operating frequency f0 of the pulse drive signal deviates from the resonant frequency f of the screen cover. CG The operating frequency f0 of the pulse drive signal is selected to make the ultrasonic echo signal the strongest or the ultrasonic echo signal the highest signal-to-noise ratio. The ultrasonic echo signal is the ultrasonic signal reflected by the detection unit above the display screen and received by the under-screen ultrasonic sensor. The step of applying the pulse drive signal to the under-screen ultrasonic sensor includes: generating a control pulse signal through a pulse signal generation unit and processing the control pulse signal through a resonant unit to obtain a pulse drive signal, so as to apply the pulse drive signal to the under-screen ultrasonic sensor.

[0143] S104: Perform feature detection based on the ultrasonic echo signal to identify the unit to be detected above the display screen.

[0144] It should be understood that the ultrasonic detection method in this embodiment can apply a pulse drive signal to the under-display ultrasonic sensor to drive the under-display ultrasonic sensor to emit ultrasonic signals upwards towards the display screen. The operating frequency f0 of the pulse drive signal deviates from the resonant frequency f of the screen cover plate of the display screen. CG Furthermore, the operating frequency f0 of the pulse drive signal is selected to maximize the ultrasonic echo signal or maximize its signal-to-noise ratio. The ultrasonic echo signal is the ultrasonic signal reflected by the unit under the display screen and received by the ultrasonic sensor under the screen. Therefore, this solution can select a high-performance operating frequency of the pulse drive signal to ensure the quality of the ultrasonic echo signal. In addition, in this embodiment, a control pulse signal can be generated by a pulse signal generation unit, and a pulse drive signal can be obtained by processing the control pulse signal through a resonant unit. The pulse drive signal is then applied to the ultrasonic sensor under the screen, thereby effectively realizing the generation, application, and selection of the operating frequency of the pulse drive signal. Moreover, in this embodiment, feature detection is performed based on the high-quality ultrasonic echo signal obtained above, which facilitates accurate identification of the unit under the display screen, effectively improves the clarity of ultrasonic detection imaging, and enhances the ultrasonic detection effect and performance.

[0145] In some optional embodiments, the operating frequency f0 of the pulse drive signal and the resonant frequency f of the screen cover are... CG The following condition must be met: f0 < f CG .

[0146] In some optional embodiments, the operating frequency f0 of the pulse drive signal, the resonant frequency f1 of the under-display ultrasonic sensor, and the resonant frequency f of the screen cover are all specified. CG The following conditions must be met: f0 < f1 < f CG .

[0147] In some optional embodiments, the operating frequency f0 of the pulse drive signal and the operating frequency f of the control pulse signal are... CTRL The resonant frequency f of the resonant unit LC The following conditions must be met between them: f CTRL <f0<f LC .

[0148] In some optional embodiments, the operating frequency f0 of the pulse drive signal, the resonant frequency f1 of the under-screen ultrasonic sensor, and the resonant frequency f2 of the display screen satisfy the following relationship: f0 < f1 < f2.

[0149] In some alternative embodiments, the resonant frequency f of the resonant unit LC The range is 0.75f2 to 1.25f2.

[0150] In some optional embodiments, the under-display ultrasonic sensor is an under-display ultrasonic fingerprint sensor, and the feature detection is used for fingerprint feature detection.

[0151] In some optional embodiments, the method further includes: changing the operating frequency f of the control pulse signal through the pulse signal generation unit. CTRL The operating frequency f0 of the pulse drive signal is dynamically adjusted.

[0152] In some alternative embodiments, the operating frequency f of the control pulse signal is... CTRL The resonant frequency f1 of the under-display ultrasonic sensor and the resonant frequency f2 of the display screen satisfy the following relationship: , where 0.01≤α≤2.

[0153] In some optional embodiments, the display screen further includes a display body located between the under-screen ultrasonic sensor and the screen cover; wherein the resonant frequency f of the display body is... panel The resonant frequency f2 of the display screen and the resonant frequency f of the screen cover plate. CG The following conditions must be met between them: f panel <f2<fCG .

[0154] In some optional embodiments, the display screen further includes a display body and a screen film, wherein the display body is located between the under-display ultrasonic sensor and the screen cover, and the screen cover is located between the display body and the screen film; wherein the resonant frequency f of the display body is... panel The resonant frequency f2 of the display screen and the resonant frequency f of the screen cover plate. CG The resonant frequency f of the screen film prtf The following conditions must be met between them: f display <f2<f prtf , where f panel <f display <f CG .

[0155] In some optional embodiments, the display screen further includes a display body located between the under-screen ultrasonic sensor and the screen cover; the operating frequency f of the control pulse signal is... CTRL Located between a first peak frequency and a second peak frequency, wherein the first peak frequency and the second peak frequency are two adjacent peak frequencies in the frequency response curve of the display body and the frequency response curve of the screen cover, respectively, and the first peak frequency is less than the second peak frequency.

[0156] In some alternative embodiments, both the first peak frequency and the second peak frequency are in the range of 9MHz to 13MHz.

[0157] In some alternative embodiments, the operating frequency f of the control pulse signal is... CTRL The deviation from the third peak frequency, wherein the third peak frequency is the peak frequency in the ratio of the spectrum of the first echo signal to the spectrum of the second echo signal, wherein the first echo signal is the ultrasonic signal received by the under-screen ultrasonic sensor when the unit under test is not placed above the display screen, and the second echo signal is the ultrasonic signal received by the under-screen ultrasonic sensor when the unit under test is placed above the display screen.

[0158] In some alternative embodiments, the operating frequency f of the control pulse signal is... CTRL The peak frequency is less than the third peak frequency and greater than the fourth peak frequency, wherein the fourth peak frequency is the peak frequency in the spectrum of the first echo signal and / or the spectrum of the second echo signal that is closest to the third peak frequency and less than the third peak frequency.

[0159] In some optional embodiments, the step of performing feature detection based on the ultrasonic echo signal to identify the unit to be detected above the display screen includes: receiving an ultrasonic detection signal generated by the ultrasonic echo signal through a receiving module, and performing feature detection based on the ultrasonic detection signal to identify the unit to be detected above the display screen.

[0160] Wherein, the resonant frequency f of the receiving module RX At least one of the following conditions must be met:

[0161] The resonant frequency f of the receiving module RX Not equal to the operating frequency f of the control pulse signal CTRL ;

[0162] The resonant frequency f of the receiving module RX It is equal to the resonant frequency f2 of the display screen.

[0163] It should be understood that the relevant content and beneficial effects of the various optional embodiments of the above-described ultrasonic testing method have been described in detail in the embodiments of the ultrasonic testing system 100 above, and can be understood in conjunction with the above content, and will not be repeated here.

[0164] It is understood that the above description of the ultrasonic testing scheme in the embodiments of this disclosure is only some optional embodiments of this disclosure and is not a limitation on the embodiments of this disclosure.

[0165] Reference Figure 10 As shown, this embodiment of the present disclosure also provides an electronic device 300, which includes the ultrasonic detection system 100 of any of the foregoing claims. Optionally, the electronic device 300 may include, but is not limited to, a mobile phone, a tablet, a computer, an in-vehicle system, or other electronic devices.

[0166] This disclosure also provides a computer storage medium storing a computer program that, when executed by a processor, implements the ultrasonic detection method as described in any of the foregoing embodiments. Optionally, the computer storage medium includes, but is not limited to, a compact disc read-only memory (CD-ROM), a random access memory (RAM), a floppy disk, a hard disk, or a magneto-optical disk.

[0167] This disclosure also provides a computer program product, which includes a computer program that, when executed by a processor, implements the ultrasonic detection method as described in any of the foregoing embodiments.

[0168] It should be understood that the ultrasonic testing method, electronic device 300, computer storage medium, and computer program product embodiments in this disclosure have been described in detail in the aforementioned ultrasonic testing system 100 embodiments. Therefore, their related content and beneficial effects can be understood by referring to the above embodiments, and will not be repeated here.

[0169] Furthermore, it should be noted that the user-related information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to sample data used for training the model, data used for analysis, stored data, displayed data, etc.) involved in the embodiments of this disclosure are all information and data authorized by the user or fully authorized by all parties. Moreover, the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0170] It should be noted that, depending on the implementation needs, the various components / steps described in the embodiments of this disclosure can be broken down into more components / steps, or two or more components / steps or parts of the operations of components / steps can be combined into new components / steps to achieve the purpose of the embodiments of this disclosure. It should be understood that the various technical features in the technical solutions of the embodiments of this disclosure can be combined or broken down in any suitable manner.

[0171] The methods described above according to embodiments of this disclosure can be implemented in hardware, firmware, or as software or computer code that can be stored in a recording medium (such as a CD-ROM, RAM, floppy disk, hard disk, or magneto-optical disk), or as computer code originally stored on a remote recording medium or a non-transitory machine-readable medium and to be stored on a local recording medium, downloaded over a network. Thus, the methods described herein can be stored on a recording medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware (such as an Application Specific Integrated Circuit (ASIC) or a Field Programmable Gate Array (FPGA)). It is understood that the computer, processor, microprocessor controller, or programmable hardware includes storage components (e.g., Random Access Memory (RAM), Read-Only Memory (ROM), Flash Memory, etc.) capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods described herein. Furthermore, when a general-purpose computer accesses code used to implement the methods shown herein, the execution of the code transforms the general-purpose computer into a dedicated computer for performing the methods shown herein.

[0172] It should be noted that the various figures involved in the embodiments of this disclosure are only for the purpose of illustrative purposes. The figures involving structures may not be drawn to scale, and the figures are not intended to limit the embodiments of this disclosure in any way.

[0173] Those skilled in the art will recognize that the units and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for specific applications, but such implementations should not be considered beyond the scope of the embodiments disclosed herein.

[0174] The above embodiments are only used to illustrate the embodiments of this disclosure, and are not intended to limit the embodiments of this disclosure. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of this disclosure. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of this disclosure, and the patent protection scope of the embodiments of this disclosure should be defined by the claims.

[0175] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". It should be noted that the concepts of "first", "second", etc., mentioned in the embodiments of this disclosure are only used to distinguish different devices, modules, or units, and are not used to limit the order of functions performed by these devices, modules, or units or their interdependencies. It should be noted that the modifications of "a" and "a plurality" mentioned in the embodiments of this disclosure are illustrative and not restrictive, and those skilled in the art should understand that unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0176] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this disclosure, and are not intended to limit them. Although the embodiments of this disclosure have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure.

Claims

1. An ultrasonic testing method, comprising: A pulse drive signal is applied to the under-display ultrasonic sensor to drive the sensor to emit ultrasonic signals upwards toward the display screen, wherein the display screen includes a screen cover, and the operating frequency f0 of the pulse drive signal deviates from the resonant frequency f of the screen cover. CG The operating frequency f0 of the pulse drive signal is selected to make the ultrasonic echo signal the strongest or the ultrasonic echo signal the highest signal-to-noise ratio. The ultrasonic echo signal is the ultrasonic signal reflected by the detection unit above the display screen and received by the under-screen ultrasonic sensor. The step of applying the pulse drive signal to the under-screen ultrasonic sensor includes: generating a control pulse signal through a pulse signal generation unit and processing the control pulse signal through a resonant unit to obtain a pulse drive signal, so as to apply the pulse drive signal to the under-screen ultrasonic sensor. Feature detection is performed based on the ultrasonic echo signal to identify the unit to be detected above the display screen.

2. The method according to claim 1, wherein, The method satisfies at least one of the following conditions: The operating frequency f0 of the pulse drive signal and the resonant frequency f of the screen cover plate CG The following condition must be met: f0 < f CG ; The operating frequency f0 of the pulse drive signal, the resonant frequency f1 of the under-screen ultrasonic sensor, and the resonant frequency f of the screen cover are all specified. CG The following conditions must be met: f0 < f1 < f CG ; The operating frequency f0 of the pulse drive signal and the operating frequency f of the control pulse signal CTRL The resonant frequency f of the resonant unit LC The following conditions must be met between them: f CTRL <f0<f LC ; The operating frequency f0 of the pulse drive signal, the resonant frequency f1 of the under-screen ultrasonic sensor, and the resonant frequency f2 of the display screen satisfy the following condition: f0 < f1 < f2. The resonant frequency f of the resonant unit LC The range is 0.75f² ~ 1.25f²; The under-display ultrasonic sensor is an under-display ultrasonic fingerprint sensor, and the feature detection is used for fingerprint feature detection.

3. The method according to claim 1, wherein, The method further includes: The operating frequency f of the control pulse signal is changed by the pulse signal generation unit. CTRL The operating frequency f0 of the pulse drive signal is dynamically adjusted.

4. The method according to claim 1, wherein, The operating frequency f of the control pulse signal CTRL The resonant frequency f1 of the under-display ultrasonic sensor and the resonant frequency f2 of the display screen satisfy the following relationship: , where 0.01≤α≤2.

5. The method according to any one of claims 1-4, wherein, The display screen also includes a display body, which is located between the under-screen ultrasonic sensor and the screen cover; wherein... The resonant frequency f of the display screen panel The resonant frequency f2 of the display screen and the resonant frequency f of the screen cover plate. CG The following conditions must be met between them: f panel <f2<f CG .

6. The method according to any one of claims 1-4, wherein, The display screen further includes a display body and a screen film. The display body is located between the under-display ultrasonic sensor and the screen cover, and the screen cover is located between the display body and the screen film. The resonant frequency f of the display screen panel The resonant frequency f2 of the display screen and the resonant frequency f of the screen cover plate. CG The resonant frequency f of the screen film prtf The following conditions must be met between them: f display <f2<f prtf , where f panel <f display <f CG .

7. The method according to any one of claims 1-4, wherein, The display screen also includes a display body, which is located between the under-screen ultrasonic sensor and the screen cover. The operating frequency f of the control pulse signal CTRL Located between a first peak frequency and a second peak frequency, wherein the first peak frequency and the second peak frequency are two adjacent peak frequencies in the frequency response curve of the display body and the frequency response curve of the screen cover, respectively, and the first peak frequency is less than the second peak frequency.

8. The method according to claim 7, wherein, Both the first peak frequency and the second peak frequency are within the range of 9MHz to 13MHz.

9. The method according to any one of claims 1-4, wherein, The operating frequency f of the control pulse signal CTRL The deviation from the third peak frequency, wherein the third peak frequency is the peak frequency in the ratio of the spectrum of the first echo signal to the spectrum of the second echo signal, wherein the first echo signal is the ultrasonic signal received by the under-screen ultrasonic sensor when the unit under test is not placed above the display screen, and the second echo signal is the ultrasonic signal received by the under-screen ultrasonic sensor when the unit under test is placed above the display screen.

10. The method according to claim 9, wherein, The operating frequency f of the control pulse signal CTRL The peak frequency is less than the third peak frequency and greater than the fourth peak frequency, wherein the fourth peak frequency is the peak frequency in the spectrum of the first echo signal and / or the spectrum of the second echo signal that is closest to the third peak frequency and less than the third peak frequency.

11. The method according to any one of claims 1-4, wherein, The step of performing feature detection based on the ultrasonic echo signal to identify the unit to be detected above the display screen includes: The receiving module receives the ultrasonic detection signal generated by the ultrasonic echo signal and performs feature detection based on the ultrasonic detection signal to identify the unit to be detected above the display screen. Wherein, the resonant frequency f of the receiving module RX At least one of the following conditions must be met: The resonant frequency f of the receiving module RX Not equal to the operating frequency f of the control pulse signal CTRL ; The resonant frequency f of the receiving module RX It is equal to the resonant frequency f2 of the display screen.

12. An ultrasonic testing system, comprising: The system includes a drive module, an under-display ultrasonic sensor, a display screen, and a detection module, wherein the display screen includes a screen cover. The driving module includes a pulse signal generation unit and a resonant unit. The driving module is used to: generate a control pulse signal through the pulse signal generation unit, and process the control pulse signal through the resonant unit to obtain a pulse driving signal, so as to apply the pulse driving signal to the under-display ultrasonic sensor to drive the under-display ultrasonic sensor to emit ultrasonic signals upwards towards the display screen; the operating frequency f0 of the pulse driving signal deviates from the resonant frequency f of the screen cover. CG The operating frequency f0 of the pulse drive signal is selected to make the ultrasonic echo signal the strongest or the ultrasonic echo signal the highest signal-to-noise ratio. The ultrasonic echo signal is the ultrasonic signal that is reflected by the detection unit above the display screen and received by the ultrasonic sensor under the screen. The detection module is used to perform feature detection based on the ultrasonic echo signal to identify the unit to be detected above the display screen.

13. An electronic device, comprising: The ultrasonic testing system as described in claim 12.

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

15. A computer program product comprising a computer program that, when executed by a processor, implements the method as described in any one of claims 1-11.

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