Ultrasonic image acquisition method, ultrasonic fingerprint chip, electronic device and ultrasonic fingerprint detection method

Abstract

Embodiments of the present application provide an ultrasonic image acquisition method, an ultrasonic fingerprint chip, an electronic device and an ultrasonic fingerprint detection method. The ultrasonic image acquisition method comprises: in response to meeting an automatic image acquisition condition, acquiring a current temperature of an environment in which the ultrasonic fingerprint chip is located; determining whether a preset image acquisition condition is met based on the current temperature, wherein the preset image acquisition condition is a condition for indicating that the number of background images obtained at the current temperature is not up to standard, and the background image is an ultrasonic image without fingerprints collected by the ultrasonic fingerprint chip; and if the preset image acquisition condition is met, causing the ultrasonic fingerprint chip to perform ultrasonic image acquisition to obtain at least one target background image at the current temperature.

Description

Technical Field

[0001] This application relates to the field of ultrasonic fingerprint technology, and in particular to an ultrasonic image acquisition method, an ultrasonic fingerprint chip, an electronic device, and an ultrasonic fingerprint detection method. Background Technology

[0002] Current ultrasonic fingerprint systems can acquire an ultrasonic fingerprint image when a finger is pressed, and then acquire a fingerprint-free background image (also called a base image) when the finger is released. Subtracting the background image from the pressed ultrasonic fingerprint image yields a clear fingerprint image. A good background image is generally considered to have the following characteristics: it should be free of foreign objects or residual fingerprints, and the temperature at which it is acquired should be as close as possible to the temperature at which the fingerprint is acquired. However, since the temperature at the time of finger pressing cannot be predicted when using an ultrasonic fingerprint chip, related technologies typically acquire the background image the instant the finger is released after pressing. This acquired background image may contain foreign objects (such as residue left from the finger pressing). After subsequent use, this background image with foreign objects is usually stored in a background image library for use under similar temperature conditions. However, because the background images acquired by the related technical solutions often contain foreign objects, the detection accuracy of ultrasonic fingerprint detection using these images is easily reduced. Furthermore, storing background images containing foreign objects in the background image library can negatively impact the accuracy of subsequent ultrasonic fingerprint detection under similar temperature conditions. Therefore, new technical solutions are urgently needed to improve this problem. Summary of the Invention

[0003] In view of the above, embodiments of this application provide an ultrasonic image acquisition method, an ultrasonic fingerprint chip, an electronic device, and an ultrasonic fingerprint detection method to at least partially solve the above problems.

[0004] According to a first aspect of the present application, an ultrasonic image acquisition method is provided, comprising: in response to meeting automatic image acquisition conditions, acquiring the current temperature of the environment in which an ultrasonic fingerprint chip is located; determining, based on the current temperature, whether a preset image acquisition condition is met, wherein the preset image acquisition condition is a condition used to indicate that the number of background images obtained at the current temperature has not reached a certain level, and the background image is an ultrasonic image without fingerprints acquired by the ultrasonic fingerprint chip; if the preset image acquisition condition is met, causing the ultrasonic fingerprint chip to perform ultrasonic image acquisition to obtain at least one target background image at the current temperature.

[0005] According to a second aspect of the embodiments of this application, an ultrasonic fingerprint chip is provided for performing the method as described in any one of the first aspects.

[0006] According to a third aspect of the embodiments of this application, an ultrasonic fingerprint module is provided, comprising: an ultrasonic fingerprint chip as described in the second aspect, and a temperature sensor; wherein the temperature sensor is electrically connected to the ultrasonic fingerprint chip and configured to collect the current temperature of the environment in which the ultrasonic fingerprint chip is located, and transmit the current temperature to the ultrasonic fingerprint chip.

[0007] According to a fourth aspect of the embodiments of this application, an electronic device is provided, including: an ultrasonic fingerprint module as described in the third aspect.

[0008] According to a fifth aspect of the embodiments of this application, an ultrasonic fingerprint detection method is provided, comprising: obtaining an ultrasonic fingerprint image acquired by an ultrasonic fingerprint chip; obtaining a background image from a background image library that matches the temperature at which the ultrasonic fingerprint image was acquired, wherein at least one background image in the background image library is a target background image acquired by the method as described in any one of the first aspects; and performing ultrasonic fingerprint detection based on the ultrasonic fingerprint image and the matching background image.

[0009] According to a sixth aspect of the embodiments of this application, a computer storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the method as described in any one of the first and fifth aspects.

[0010] According to a seventh aspect of the embodiments of this application, a computer program product is provided, which includes a computer program that, when executed by a processor, implements the method as described in any one of the first and fifth aspects.

[0011] The technical solution in this application embodiment can respond to automatic image acquisition conditions to obtain the current temperature of the environment where the ultrasonic fingerprint chip is located; then, based on the current temperature, it determines whether the preset image acquisition conditions are met, wherein the preset image acquisition conditions are used to indicate that the number of background images obtained at the current temperature has not reached the standard, and the background image is an ultrasonic image without fingerprints acquired by the ultrasonic fingerprint chip; furthermore, when the preset image acquisition conditions are met, the ultrasonic fingerprint chip is made to perform ultrasonic image acquisition, thereby effectively obtaining at least one target background image at the current temperature. Therefore, on the one hand, the technical solution in this application embodiment is not limited to acquiring the background image at the moment the finger is lifted, but can automatically acquire the current temperature after the automatic image acquisition conditions are met, and realize the automatic acquisition of the background image at the current temperature when the current temperature meets the preset image acquisition conditions. In this way, the automatically acquired background image will be more likely to be the background image within a period of time before and after the non-pressing time, that is, the situation of acquiring background images with foreign objects or residual fingerprints is reduced. Therefore, the background image is pre-stored in the background image library, and the background image at the current temperature is used for ultrasonic fingerprint detection in the future, which can more likely ensure the effect of ultrasonic fingerprint detection. Furthermore, by automatically acquiring images and storing them in the background image library in this way, the background image library can also be greatly accelerated at various temperatures. The accumulation of background images at different temperatures allows the background image library to be built more quickly, which is beneficial for the normal use of the ultrasonic fingerprint chip in fingerprint detection under various temperature environments. On the other hand, since the embodiments of this application only perform ultrasonic image acquisition when the current temperature meets the preset image acquisition conditions (that is, when the number of background images obtained at the current temperature is insufficient), so as to obtain at least one target background image, unnecessary image acquisition operations can be effectively avoided when there are enough background images at the current temperature. This ensures that a sufficient number of background images at the current temperature can be acquired for subsequent use, thereby improving the acquisition performance of background images at the current temperature while effectively reducing the power consumption of the ultrasonic fingerprint chip. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0013] Figure 1 A schematic flowchart illustrating some examples of ultrasonic image acquisition methods in embodiments of this application is shown.

[0014] Figure 2 A schematic block diagram of an ultrasonic fingerprint module, representing some examples of embodiments of this application, is shown.

[0015] Figure 3 A flowchart of some optional sub-steps of step S104 in an embodiment of this application is shown.

[0016] Figure 4 A schematic diagram showing the correspondence between multiple sites and multiple target temperatures is presented in an example recording.

[0017] Figure 5 A flowchart illustrating some of the optional steps in determining the recording diagram is shown.

[0018] Figure 6A The data shown is the corresponding data of a statistical histogram for a certain screen protector application status.

[0019] Figure 6B The corresponding data for the statistical histograms of several screen protector application states are shown in the example.

[0020] Figure 7 A flowchart illustrating an example of triggering ultrasonic image acquisition via an interrupt signal is shown.

[0021] Figure 8 Schematic diagrams of some examples of electronic devices in embodiments of this application are shown.

[0022] Figure 9 A schematic flowchart of an ultrasonic fingerprint detection method, representing some examples of embodiments of this application, is shown.

[0023] Explanation of reference numerals in the attached figures: 100. Ultrasonic fingerprint chip; 200. Temperature sensor; 300. Ultrasonic fingerprint module; 400. Electronic equipment; 410. Main control unit. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and thoroughly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0025] Current ultrasonic fingerprint systems can acquire an ultrasonic fingerprint image when the finger is pressed, and then acquire a background image (also called a base image) without fingerprints when the finger is not pressed. By subtracting the background image from the ultrasonic fingerprint image, a clear fingerprint image can be reconstructed. Generally, a good background image is considered to have the following characteristics: it should be free of foreign objects or residual fingerprints, and the temperature at which the background image is acquired should be as close as possible to the temperature at which the fingerprint is acquired when it is pressed.

[0026] However, since the temperature of a finger pressing the fingerprint sensor cannot be predicted during ultrasonic fingerprint chip use, related technologies typically capture a background image the instant the finger is released after pressing. This captured image may contain foreign objects (such as residue left from the finger pressing). Afterward, this image with foreign objects is usually stored in a background image library for use under similar temperature conditions. However, because the background images captured by these technologies often contain foreign objects, the accuracy of ultrasonic fingerprint detection using these images is easily reduced. Furthermore, storing background images with foreign objects in the background image library can negatively impact the accuracy of ultrasonic fingerprint detection under similar temperature conditions in subsequent uses.

[0027] In some situations, users may suddenly move from a normal temperature environment to a low or high temperature environment, creating a significant temperature difference in the use of ultrasonic fingerprint scanners. Therefore, in such temperature difference scenarios, if there is no background image corresponding to the temperature beforehand, using any other existing background image for fingerprint detection can easily lead to poor detection performance or even detection failure. On the other hand, if the background image is captured the moment the hand is lifted after pressing, the captured background image may contain foreign objects, which can still reduce the detection accuracy when using the background image for ultrasonic fingerprint detection.

[0028] It should be understood that the embodiments of this application provide a new technical solution that can at least partially improve the problems existing in related technologies. The following detailed description is provided in conjunction with the accompanying drawings of the embodiments of this application.

[0029] According to a first aspect of the embodiments of this application, an ultrasonic image acquisition method is provided. (Refer to...) Figure 1 The flowchart shown illustrates that the ultrasonic image acquisition method may include the following steps S102, S104, and S106, specifically: S102: In response to meeting the automatic image acquisition conditions, obtain the current temperature of the environment in which the ultrasonic fingerprint chip is located.

[0030] Optionally, the ultrasonic image acquisition method in this embodiment can be executed by the ultrasonic fingerprint chip 100, or it can be jointly executed by the ultrasonic fingerprint chip 100 and the main control unit 410 of the electronic device 400 (that is, the ultrasonic fingerprint chip 100 performs some steps, and the main control unit 410 performs some steps). In some embodiments, it can be described that the method is executed by the ultrasonic fingerprint chip 100.

[0031] The ultrasonic fingerprint chip 100 can be used for ultrasonic fingerprint detection (also known as ultrasonic fingerprint recognition). It can acquire ultrasonic images by emitting ultrasonic signals and receiving ultrasonic echo signals reflected back by fingerprint carriers such as fingers. The specific structure of the ultrasonic fingerprint chip 100 is not specifically limited in this embodiment. The ultrasonic fingerprint chip 100 can be placed at any location on the electronic device 400 as needed. For example, in some examples, it can be located below the screen, on the side, or inside the back panel of the electronic device 400, thereby facilitating under-screen, side, or rear ultrasonic fingerprint detection.

[0032] The electronic device 400 can be implemented as any electronic device that requires ultrasonic fingerprint detection functionality. Its specific type is not specifically limited in this embodiment, and may include, but is not limited to, smartphones, tablets, laptops, smartwatches, smart locks, etc. The main control unit 410 can be a unit in the electronic device 400 that performs processing and control functions, and may be implemented as, but is not limited to, a CPU (Central Processing Unit) or an MCU (Microcontroller Unit).

[0033] In this embodiment, when the automatic image acquisition condition is met, the current temperature of the environment where the ultrasonic fingerprint chip 100 is located can be obtained. It should be noted that in this embodiment, the current temperature can be obtained regardless of whether the user's finger is lifted, to facilitate subsequent determination of whether ultrasonic image acquisition is necessary. The specific form of the automatic image acquisition condition can be flexibly set according to actual needs. For example, the automatic image acquisition condition can be implemented as an automatic image acquisition time condition. Optionally, a time interval can be preset, and after each time interval, the automatic image acquisition time condition is considered met, thus allowing the acquisition of the current temperature of the environment where the ultrasonic fingerprint chip 100 is located. Optionally, when determining whether the automatic image acquisition time condition is met, a timer can be used. After the timer starts, if the timer expires (i.e., the time interval is reached), the automatic image acquisition time condition is considered met; if the timer does not expire, the automatic image acquisition time condition is not met. This time interval can be set as needed according to factors such as power consumption and user experience. For example, 30 seconds can be used as a simple example, meaning that after every 30 seconds, the automatic image acquisition condition is considered met; however, this is not a limitation.

[0034] In other embodiments, the automatic image acquisition conditions may also be based on specific event triggering conditions, or other reasonable forms of automatic image acquisition conditions. For example, as an example, if a specific event occurs where the ultrasonic fingerprint chip 100 or the electronic device 400 enters a sleep state and then wakes up, it can be considered that the automatic image acquisition conditions are met. Of course, these are just some examples of automatic image acquisition conditions that are easy to understand. Appropriate automatic image acquisition conditions can be reasonably set as needed, and there is no unique limitation in the embodiments of this application.

[0035] Since the acoustic performance of the ultrasonic fingerprint chip 100 changes with temperature, the current temperature of the environment in which the ultrasonic fingerprint chip 100 is located directly affects the quality of the ultrasonic image acquired by the ultrasonic fingerprint chip 100. Accordingly, the background images acquired by the ultrasonic fingerprint chip 100 under different temperature conditions usually differ. In the actual ultrasonic fingerprint detection stage, when the temperature at which the finger presses to acquire the ultrasonic fingerprint image is close to the temperature at which the background image is acquired, subtracting the background image from the ultrasonic fingerprint image can effectively restore a clear fingerprint image. Therefore, in this embodiment, when the automatic image acquisition conditions are met, the current temperature of the environment in which the ultrasonic fingerprint chip 100 is located is automatically obtained. This current temperature can be used as a basis to determine whether the preset image acquisition conditions are met, thereby deciding whether to allow the ultrasonic fingerprint chip 100 to execute the ultrasonic image acquisition process, and the acquired background images can be managed according to different temperatures.

[0036] Optionally, the current temperature can be obtained in any suitable way. For example, it can be obtained through a temperature sensor 200, the type of which is not specifically limited here. Furthermore, the specific setting of the temperature sensor 200 can be selected as needed, for example, it can be set in the electronic device 400. Optionally, the ultrasonic fingerprint chip 100 can be electrically connected to the temperature sensor. When the automatic image acquisition conditions are met, the ultrasonic fingerprint chip 100 can acquire the current temperature collected by the temperature sensor 200, which is electrically connected to the ultrasonic fingerprint chip 100, so as to determine whether ultrasonic image acquisition needs to be performed based on the current temperature. Optionally, the ultrasonic fingerprint chip 100 can be directly connected to the temperature sensor 200. This allows the current temperature collected by the temperature sensor 200 to be acquired by the ultrasonic fingerprint chip 100 with low latency and power consumption, and can achieve direct acquisition without the need for the main control unit 410 of the electronic device 400, thereby ensuring the real-time performance and accuracy of the current temperature acquisition.

[0037] In some alternative embodiments, refer to Figure 2 As shown, the ultrasonic fingerprint chip 100 and the temperature sensor 200 can be integrated into the ultrasonic fingerprint module 300, meaning both can be part of the ultrasonic fingerprint module 300. For example, see reference... Figure 2 As shown, the ultrasonic fingerprint module 300 may include an ultrasonic fingerprint chip 100 and a temperature sensor 200. The ultrasonic fingerprint chip 100 and the temperature sensor 200 are electrically connected (e.g., they can be directly connected). The temperature sensor 200 can be configured to collect the current temperature of the environment in which the ultrasonic fingerprint chip 100 is located and transmit the current temperature to the ultrasonic fingerprint chip 100. Thus, the ultrasonic fingerprint module 300 realizes ultrasonic fingerprint detection through the ultrasonic fingerprint chip 100 and collects temperature through the temperature sensor 200, thereby facilitating the implementation of the technical solutions in the embodiments of this application.

[0038] S104: Based on the current temperature, determine whether the preset image acquisition conditions are met. The preset image acquisition conditions are used to indicate that the number of background images obtained at the current temperature has not met the standard. The background images are ultrasonic images without fingerprints acquired by the ultrasonic fingerprint chip.

[0039] In this embodiment, after obtaining the current temperature, it can be determined whether preset image acquisition conditions are met based on the current temperature. The preset image acquisition conditions are used to indicate that the number of background images obtained at the current temperature has not reached the required level. For example, assuming that all obtained background images are stored in a preset background image library, the preset image acquisition conditions can indicate that the number of background images in the background image library at the current temperature has not reached the required level.

[0040] It should be understood that the preset image acquisition conditions are conditions used in this embodiment to further determine whether it is necessary to perform ultrasonic image acquisition at the current temperature. The ultrasonic fingerprint chip 100 will only perform ultrasonic image acquisition to acquire background images when the preset image acquisition conditions are met. For example, if it is determined that the preset image acquisition conditions are met based on the current temperature, it means that the number of background images obtained under the current temperature conditions is insufficient to meet the needs of subsequent ultrasonic fingerprint detection, and it is necessary to further acquire background images at the current temperature. Conversely, if it is determined that the preset image acquisition conditions are not met based on the current temperature, it means that the number of background images obtained under the current temperature conditions is sufficient to meet the needs of subsequent ultrasonic fingerprint detection, and it is not necessary to further acquire background images at the current temperature.

[0041] Therefore, in this embodiment, ultrasonic image acquisition is only performed when the current temperature meets the preset image acquisition conditions (that is, when the number of background images obtained at the current temperature is insufficient) in order to obtain at least one target background image. This can effectively avoid unnecessary image acquisition operations when there are enough background images at the current temperature, and ensure that a sufficient number of background images at the current temperature can be acquired for subsequent use. In this way, the acquisition performance of background images at the current temperature is improved while effectively reducing the power consumption of the ultrasonic fingerprint chip.

[0042] It should be noted that whether the number of background images meets the standard can be measured in a suitable way depending on the temperature. The methods for different temperatures can be the same or different. For example, whether the number of background images meets the standard can be measured by the total number meeting the standard, or it can be measured by meeting the standard under multiple different configuration states (such as the screen protector application state mentioned below).

[0043] The embodiments of this application do not limit the specific implementation of step S104. In some optional embodiments, refer to Figure 3 The flowchart shown includes steps S1042-S1046, specifically: S1042: Obtain a recording image, wherein the recording image includes multiple sites, each site corresponding to a target temperature within a predetermined temperature range, and the assignment of the site value is used to indicate the status of the number of background images at the corresponding target temperature meeting the standard.

[0044] In this embodiment, the preset temperature range can be set as needed. For example, it can be reasonably set based on the temperature range that the ultrasonic fingerprint chip 100 may encounter in actual operation. In one example, the preset temperature range can be set to -30℃ to 60℃. Of course, this is just an example for ease of understanding and is not limited to this.

[0045] The multiple sites included in the recording graph can each correspond to multiple target temperatures within a preset temperature range. For example, target temperatures can be selected from the preset temperature range by dividing it into certain temperature intervals. Taking a preset temperature range of -30℃ to 60℃ as an example, in one example, assuming the temperature interval is set to 1℃, multiple target temperatures can include: -30℃, -29℃, -28℃, ..., 0℃, 1℃, 2℃, ..., 58℃, 59℃, 60℃, that is, a total of 91 target temperatures. It should be noted that the total number of sites in the recording graph can be the same as or greater than the total number of target temperatures, as long as there are enough sites to correspond to multiple target temperatures.

[0046] In this embodiment, the values ​​assigned to the sites in the recording graph are used to indicate whether the number of background images at the corresponding target temperature meets the requirements. By assigning values ​​to the sites corresponding to the target temperature, it can be determined whether the number of existing background images at a certain target temperature in the background image library is sufficient for subsequent fingerprint detection, thereby determining whether the preset image acquisition conditions are met. For example, in the aforementioned preset temperature range of -30℃ to 60℃, there are 91 sites in the recording graph corresponding to the target temperatures. These 91 sites respectively indicate whether the number of background images at the 91 target temperatures meets the requirements, and the target values ​​assigned to these 91 sites can be used to determine whether the number of existing background images at the 91 target temperatures is sufficient for subsequent fingerprint detection. It is understood that if there are more sites in the recording graph, the values ​​assigned to these additional sites may not correspond to the target temperatures.

[0047] The recording graph can be implemented in any form, such as a bitmap, pixel graph, or node graph, and there is no unique limitation in the embodiments of this application. Furthermore, the form of the recording graph used to assign values ​​to the points in the recording graph can be determined as needed, and there is no unique limitation here either.

[0048] S1044: Based on the current temperature, obtain the target assignment of the site corresponding to the target temperature that matches the current temperature from the recording graph.

[0049] After acquiring the recorded image, based on the current temperature obtained in step S102 above, a target value can be assigned to the site corresponding to the target temperature that matches the current temperature from the recorded image. This target value can directly reflect the status of the number of background images at the current temperature, thus providing a basis for subsequent steps to determine whether the preset image acquisition conditions are met.

[0050] Optionally, "temperature matching" here can refer to a target temperature that is closest to the current temperature. For example, if the current temperature is 20℃, then the target temperature that matches this current temperature is 20℃, which is the same as the current temperature. As another example, if the current temperature is 20.2℃, it is closer to the target temperature of 20℃ and farther from the target temperature of 21℃, so the target temperature that matches this current temperature is 20℃. Yet another example, if the current temperature is 20.7℃, it is closer to the target temperature of 21℃ and farther from the target temperature of 20℃, so the target temperature that matches this current temperature is 21℃. Other cases can be deduced similarly.

[0051] S1046: Based on the target assignment, determine whether the preset image acquisition conditions are met.

[0052] The target value obtained in step S1044 reflects the status of the number of background images at the current temperature meeting the target. Based on this status, it can be determined whether the current temperature meets the preset image acquisition conditions. If the target value indicates that the number of background images at the current temperature does not meet the target, then the preset image acquisition conditions are met, and the ultrasonic fingerprint chip 100 can then perform ultrasonic image acquisition to obtain at least one target background image at the current temperature. Conversely, if the target value indicates that the number of background images at the current temperature meets the target, then the preset image acquisition conditions are not met, and the ultrasonic fingerprint chip 100 will not perform ultrasonic image acquisition to avoid unnecessary image acquisition operations.

[0053] It should be understood that the optional implementation of steps S1042 to S1044 in the embodiments of this application, on the one hand, involves acquiring a recording image and, based on the current temperature, obtaining a target value for the location corresponding to the target temperature that matches the current temperature from the recording image. Based on the target value, it is possible to efficiently and accurately determine whether the preset image acquisition conditions are met at the current temperature. This can further effectively ensure that ultrasonic image acquisition is performed only when the preset image acquisition conditions are met at the current temperature (i.e., when the number of background images obtained at the current temperature is insufficient), so as to obtain at least one target background image. Therefore, it can effectively avoid unnecessary image acquisition operations when the number of background images at the current temperature is sufficient, and can ensure that a sufficient number of images can be acquired. The system acquires background images at the current temperature for subsequent use, thereby effectively reducing the power consumption of the ultrasonic fingerprint chip and improving the acquisition performance of background images at the current temperature. On the other hand, since this embodiment innovatively determines whether the preset acquisition conditions are met by recording the image, it is not necessary to count the number of background images obtained from the background image library in real time after each acquisition of the current temperature. Instead, when needed, it is only necessary to read the target assignment of the corresponding position of the current temperature in the recording image to quickly determine whether the preset acquisition conditions are met. This facilitates the subsequent rapid determination of whether the ultrasonic fingerprint chip 100 needs to perform ultrasonic image acquisition for the background image, thus effectively reducing computational overhead and improving system response efficiency.

[0054] In some optional embodiments, a record image in the form of a bitmap can be obtained, wherein the assignment of points in the record image in the bitmap form includes different first values ​​and second values. Based on this, if the target is determined to be assigned the first value, it is determined that the preset image acquisition conditions are met; otherwise, if the target is determined to be assigned the second value, it is determined that the preset image acquisition conditions are not met.

[0055] Bitmaps can store information in binary format. The first and second values ​​assigned to a bit can correspond to two mutually exclusive states: the number of background images at the target temperature is insufficient, and the number of background images at the target temperature is sufficient. For example, if the first value corresponds to insufficient quantity, then when the target is assigned the first value, the preset image acquisition conditions are met. Conversely, if the second value corresponds to sufficient quantity, then when the target is assigned the second value, the preset image acquisition conditions are not met. For instance, one of the first and second values ​​can be 0, and the other can be 1. For example, the first value can be 0 and the second value 1; or the first value can be 1 and the second value 0; it can be set as needed. The following example uses the first value being 0 and the second value being 1.

[0056] It is understood that by employing a bitmap-based recording image in this embodiment, the number of background images meeting the target temperature requirement can be recorded with low storage overhead and high storage efficiency. For example, using 91 target temperatures within the preset temperature range of -30℃ to 60℃, 91 sites in the bitmap assigned a first value (e.g., 0) or a second value (e.g., 1) can be used to record them completely. Therefore, the storage overhead is low and the storage efficiency is high, making it easy to configure in the ultrasonic fingerprint chip 100. Furthermore, since the bitmap-based recording image also has high read and write efficiency, reading the target assignment of the site corresponding to the target temperature matching the current temperature from the bitmap-based recording image to determine whether the preset image acquisition conditions are met can greatly improve the response speed when determining whether the preset image acquisition conditions are met. This facilitates the subsequent quick determination of whether the ultrasonic fingerprint chip 100 needs to perform ultrasonic image acquisition for the background image based on the judgment result, thus further reducing computational overhead and improving system response efficiency.

[0057] For example, Figure 4 A schematic diagram illustrating the correspondence between multiple sites and multiple target temperatures in an example recording is shown. This recording is in bitmap format. (See reference...) Figure 4 As can be seen, the recording map can include 16*16 sites (i.e., (bit0, bitmap[0]) to (bit15, bitmap

[15] )), and can record the background image quantity status at up to 256 temperatures (e.g., in one example, 256 integer temperatures from -40℃ to 215℃) using 16*16 sites respectively. For the example of 91 target temperatures in the preset temperature range of -30℃ to 60℃ selected as needed, 91 sites can be used to record the background image quantity status at these 91 target temperatures. The values ​​of these 91 sites can be set to a first value (e.g., 0) or a second value (e.g., 1) according to the number of background images at the corresponding target temperature in the background image library, and can be updated in real time. The other unused sites in the recording map (i.e., Figure 4 The values ​​assigned to the sites corresponding to the blank cells in the image can always be the second value (e.g., 1, which can be understood as other temperatures not within the preset temperature range not meeting the preset imaging conditions by default). When determining whether the preset imaging conditions are met, these unused sites can be disregarded. Of course, Figure 4The 16*16 site recording map is just an example. A total of 15*7 site recording map can also be used as needed to record the background image quantity at 91 target temperatures within the preset temperature range of -30℃ to 60℃. Alternatively, the total number of sites in the recording map can be more or less. It can be selected as needed to adapt to the temperature requirements during operation. This application embodiment does not impose a unique limitation on this.

[0058] The recording pattern in this application embodiment can be determined in any way. For example, the recording pattern can be reasonably determined based on the usage scenario of the ultrasonic fingerprint chip 100 in the electronic device 400. Optionally, for the usage scenario of under-display ultrasonic fingerprint, the ultrasonic fingerprint chip 100 can be disposed under the screen of the electronic device 400, and the screen is configured to be able to be covered with a screen protector. It should be understood that since the screen protector can be diverse and replaceable, and the screen protector will also have a significant impact on the ultrasonic image acquisition and ultrasonic fingerprint detection of the ultrasonic fingerprint chip 100, even if the temperature is the same, using a background image of one screen protector state to perform ultrasonic fingerprint detection in another screen protector state will lead to poor detection results or even detection errors. Therefore, in this application embodiment, the screen protector state can be considered to reasonably determine the recording pattern.

[0059] In some alternative embodiments, refer to Figure 5 The flowchart shown can be determined through the following steps S202~S204, specifically: S202: Obtain background image statistics corresponding to at least one film application state, wherein the background image statistics are used to indicate the statistical distribution of the number of each background image corresponding to the film application state at each target temperature in the background image library.

[0060] For example, the screen protector application status can include, but is not limited to, at least one of the following: no screen protector, tempered glass screen protector, hydrogel screen protector, etc. It should be understood that screen protectors of different brands, materials, and thicknesses can all be considered different application statuses. In the embodiments of this application, background image statistical information can be selected and maintained and configured separately for different application statuses according to actual needs.

[0061] For a given film application state, background image statistics indicate the statistical distribution of the number of background images corresponding to that application state at various target temperatures within a preset background image library. This shows how many valid background images have been stored for that application state at each target temperature. Through these background image statistics, the system can comprehensively understand the current application state and the cumulative background images at each target temperature. This facilitates accurate determination of the recorded images to accurately assess whether the current temperature meets the preset image acquisition conditions.

[0062] Background image statistics can be implemented in any suitable form. For example, in some optional embodiments, background image statistics can be implemented as statistical histograms. That is, at least one statistical histogram corresponding to the film application state can be obtained. The statistical histogram can be divided by various target temperatures within a predetermined temperature range to count the number of background images corresponding to each target temperature.

[0063] Based on this, in this embodiment, a statistical histogram can be maintained for each film application state, thereby intuitively and precisely reflecting the accumulation of background images in the background image library at various target temperatures under that film application state. Furthermore, this facilitates subsequent determination of the recorded image for accurately judging whether the current temperature meets the preset image acquisition conditions.

[0064] For example, Figure 6A The corresponding data for the statistical histogram of a certain screen protector application status is shown in the example. (Refer to...) Figure 6A For example, with a predetermined temperature range of -30℃ to 60℃, among the 91 target temperatures, the background image library stores 2 background images for 17℃ under this film-applied state, while there are 0 background images for the other 90 target temperatures. It is evident that the data from this statistical histogram can intuitively reflect the cumulative background images in the background image library for each target temperature under this film-applied state.

[0065] For example, Figure 6B The corresponding data for statistical histograms of several film application states in the example are shown. (Refer to...) Figure 6B For example, multiple film application states are denoted as cfg0, cfg1, cfg2, and cfg3, with a predetermined temperature range of -30℃ to 60℃. Among 91 target temperatures, for film application state cfg0, the background image library stores 4 background images for 17℃, while there are 0 background images for the other 90 target temperatures; for film application state cfg1, the background image library stores 4 background images for 17℃, while there are 0 background images for the other 90 target temperatures; for film application state cfg2, the background image library stores 2 background images for 17℃, while there are 0 background images for the other 90 target temperatures; and for film application state cfg3, there are 0 background images for all 91 target temperatures. It can be seen that the statistical histogram data for each film application state can intuitively reflect the cumulative background images in the background image library for each target temperature under each film application state.

[0066] S204: Determine the recording image based on background image statistical information.

[0067] In this embodiment of the application, based on the statistical information of the background images corresponding to each film application state, a comprehensive judgment can be made on the status of the number of background images of each target temperature within the predetermined temperature range, thereby assigning values ​​to the positions corresponding to each target temperature in the recording image, thus obtaining the recording image.

[0068] Based on this, the optional implementation of steps S202 to S204 in the embodiments of this application can obtain background image statistical information corresponding to at least one film application state, and then accurately determine the recording image based on the background image statistical information. Moreover, the assignment of the position in the obtained recording image can more comprehensively and accurately reflect the background image accumulation of each screen film application state and each target temperature in the current background image library. Then, by using the recording image to determine the target assignment, it is possible to accurately determine whether the current temperature meets the preset image acquisition conditions, which is beneficial to ensuring the background image acquisition performance of the ultrasonic fingerprint chip 100 in multiple film application states and multiple temperature scenarios, as well as the subsequent ultrasonic fingerprint detection performance.

[0069] In some optional embodiments, in step S204, for each target temperature within a predetermined temperature range, the number of background images corresponding to the target temperature in the statistical histogram corresponding to each film application state can be determined, and based on the determined number of multiple targets and a preset number threshold condition, values ​​are assigned to the sites in the record image to be assigned values ​​that correspond to the target temperature; after the assignment is completed at each site in the record image to be assigned values ​​that corresponds to the target temperature, a record image is obtained.

[0070] Can be combined Figure 4 and Figure 6B Let's understand this through examples. For example, Figure 4 In the record chart (the record chart to be assigned values), the predetermined temperature range can be -30℃ to 60℃, and the target temperature is a temperature of 91 integers. Therefore, the assignment of values ​​for the sites corresponding to the target temperature of 17℃ can be combined with... Figure 6B The number of background images corresponding to the target temperature of 17℃ in the film application state cfg0 (4 images), cfg1 (4 images), cfg2 (2 images), and cfg3 (0 images) is determined using a preset quantity threshold. Based on the determination result, a value is assigned to the site in the record image corresponding to the target temperature of 17℃ (e.g., a first or second value). The other 90 target temperatures can be understood analogously to the example of target temperature 17℃; no specific restrictions are imposed here. After assigning values ​​to all 91 sites corresponding to the target temperatures in the record image, the record image is obtained.

[0071] It should be noted that the preset quantity threshold conditions for different target temperatures can be the same or different, as long as they meet the actual usage requirements. There is no single limitation.

[0072] In some optional embodiments, site assignment can be implemented in the following manner: when the number of at least one target is less than a preset number threshold corresponding to the target temperature, the site in the record to be assigned the value corresponding to the target temperature is assigned a first value; or, when the number of each target is greater than or equal to the preset number threshold corresponding to the target temperature, the site in the record to be assigned the value corresponding to the target temperature is assigned a second value.

[0073] Still in combination with the above Figure 4 and Figure 6B Let's understand this using an example. For instance, if the predetermined temperature range is -30℃ to 60℃, then the target temperature is a temperature represented by 91 integers. For the assignment of a value to the location corresponding to the target temperature of 17℃, assuming the preset threshold for the number of images corresponding to 17℃ is 3, we can compare the target number of background images corresponding to the following states at 17℃: cfg0 (4 images), cfg1 (4 images), cfg2 (2 images), and cfg3 (0 images). These targets are compared to the preset threshold (3 images). It can be seen that the first two target numbers are greater than the preset threshold, while the latter two are less than the preset threshold. Therefore, if at least one target number is less than the preset threshold corresponding to the target temperature (17℃), then the location in the record to be assigned the value corresponding to the target temperature of 17℃ is assigned the first value (e.g., 0). Conversely, assuming the latter two targets also have more than 3 images, then if the number of each target is greater than or equal to a preset threshold corresponding to the target temperature of 17℃, then the site in the record image to be assigned the value corresponding to that target temperature will be assigned the second value (e.g., 1). The other 90 target temperatures can be understood analogously to the example of target temperature 17℃; no specific restrictions are imposed here. After assigning values ​​to all 91 sites corresponding to the target temperatures in the record image to be assigned, the record image is obtained.

[0074] It should be noted that the preset threshold values ​​for different target temperatures can be the same or different. The key is to meet the actual usage requirements; there is no single limitation. For example, the preset threshold values ​​for several target temperatures within a commonly used temperature range can be set slightly higher, while those for several target temperatures within a less frequently used temperature range can be set slightly lower. By setting different preset threshold values ​​for different target temperatures, background image management for different target temperatures becomes more flexible, allowing for a better balance between background image acquisition efficiency and the frequency of ultrasonic fingerprint detection.

[0075] It should be understood that for each film application state at a certain target temperature, when the number of each determined target is greater than or equal to the preset number threshold corresponding to the target temperature, it indicates that the number of background images of each film application state at the target temperature in the background image library is sufficient (meets the standard). Therefore, in this case, the site corresponding to the target temperature in the record image to be assigned a value can be assigned a second value. On the other hand, when the number of at least one determined target is less than the preset number threshold corresponding to the target temperature, it indicates that the number of background images of at least one film application state at the target temperature in the background image library is insufficient (does not meet the standard). Therefore, in this case, the site corresponding to the target temperature in the record image to be assigned a value can be assigned a first value.

[0076] Based on this, this optional site assignment method can obtain accurate and reliable recording images. After determining the target value from the recording image based on the current temperature, the target value can be used to accurately determine whether the preset image acquisition conditions are met. This effectively ensures that ultrasonic image acquisition is only performed when the preset image acquisition conditions are met at the current temperature (i.e., when the number of background images obtained at the current temperature is insufficient), thus obtaining at least one target background image. Therefore, unnecessary image acquisition operations can be avoided when there are already enough background images at the current temperature, ensuring that a sufficient number of background images at the current temperature can be acquired for subsequent use. This effectively reduces the power consumption of the ultrasonic fingerprint chip while improving the background image acquisition performance at the current temperature. Furthermore, the optional site assignment method ensures that automatic background image acquisition stops only when the number of background images corresponding to each film application state at the target temperature is sufficient. Therefore, it can effectively adapt to the diverse background image acquisition needs in various film application states and temperature scenarios in practical applications. It effectively ensures that the background image library can meet the ultrasonic fingerprint detection needs of diverse film application states and temperature scenarios, reducing the risk of ultrasonic fingerprint detection failure due to insufficient background images in a later film application state.

[0077] In some optional embodiments, at least one background image statistic can be reset when a preset state is met; wherein the preset state includes at least one of the following: the screen film has changed, the background image library file storing the background images is corrupted, or the configuration file of the ultrasonic fingerprint chip has been updated.

[0078] Resetting the background image statistics here can refer to clearing the statistical information collected in the background image statistics to zero. For example, taking the statistical histogram mentioned earlier as an example, resetting can clear the number of background image data points at the target temperature collected in the statistical histogram to zero. This allows the corresponding location at the target temperature in the record image to be reset to the first value (i.e., the value that did not meet the target, for example, it can be 0), so that background images can be re-acquired and accumulated, and the data in the background image library can be updated again.

[0079] In some embodiments, when one or more preset states are met, all background image statistics (such as the statistical histogram mentioned above) can be reset. Alternatively, when one or more preset states are met, a portion of the background image statistics can be reset.

[0080] In the aforementioned preset states, the states in which the screen protector status of the electronic device changes can be, for example, including but not limited to: changing from having a screen protector to not having one, changing from a tempered glass screen protector to a hydrogel screen protector, changing from not having a screen protector to a tempered glass screen protector, etc. For example, a user can peel off or apply a screen protector, causing a change in the screen protector status. It should be understood that the change in the screen protector alters the ultrasonic transmission environment of the ultrasonic fingerprint chip 100 beneath the screen, and the background images in the background image library may no longer be suitable for the new screen protector status. Therefore, in this embodiment, at least one background image statistical information (such as the statistical histogram mentioned above) can be reset to re-collect and accumulate background images, accelerate the updating of the background image library, and enable the background images stored in the background image library to quickly adapt to the current new screen protector status, thereby improving the ultrasonic detection performance of the ultrasonic fingerprint chip 100.

[0081] In the aforementioned preset state, if the library file of the background image library storing background images is corrupted due to various reasons (such as hardware failure, software failure, etc.), the corruption may cause the background images in the background image library to become unusable. Therefore, in this embodiment, at least one background image statistical information (such as the statistical histogram mentioned above) can be reset to re-collect and accumulate background images, accelerate the reconstruction of the background image library, and enable the background images stored in the background image library to be quickly restored to normal use, thereby benefiting the ultrasonic fingerprint chip 100 to obtain better ultrasonic detection performance in the future.

[0082] In the aforementioned preset state, when the configuration file of the ultrasonic fingerprint chip is updated—for example, when the relevant configuration file of the ultrasonic fingerprint chip 100 is updated online—the background images collected under the old configuration file version may no longer be applicable to the new configuration. The background images in the background image library need to be deleted, and new background images need to be collected to ensure the accuracy of ultrasonic fingerprint detection under the new configuration. Therefore, in this embodiment, at least one background image statistical information (such as the statistical histogram mentioned above) can be reset to re-collect and accumulate background images, accelerating the update or reconstruction of the background image library. This allows the background images stored in the background image library to quickly adapt to normal use under the currently updated configuration file, thereby improving the ultrasonic fingerprint chip 100's subsequent ultrasonic detection performance.

[0083] It is understood that, in the embodiments of this application, by actively resetting the background image statistical information (such as the statistical histogram mentioned above) in the above-mentioned multiple preset states, the system is able to actively accelerate and update and reconstruct the background image library when it senses certain preset major changes in the environment or system state, thereby reducing the time for the ultrasonic fingerprint function to go from an abnormal state to normal use, and thus improving the overall robustness and user experience of the ultrasonic fingerprint system.

[0084] S106: If the preset image acquisition conditions are met, the ultrasonic fingerprint chip is made to perform ultrasonic image acquisition to obtain at least one target background image of the current temperature.

[0085] In this embodiment, when the current temperature meets the preset image acquisition conditions, it indicates that the number of background images obtained in the background image library at the current temperature is insufficient. Therefore, the ultrasonic fingerprint chip 100 can perform ultrasonic fingerprint acquisition targeting background images without fingerprints, thereby obtaining one or more target background images. The number of target background images obtained by ultrasonic image acquisition can be selected as needed, and there is no unique limitation. Further optionally, the background image library can be updated based on at least one target background image for use in subsequent ultrasonic fingerprint detection stages.

[0086] Based on this, the technical solutions of steps S102 to S106 in the embodiments of this application can obtain the current temperature of the environment where the ultrasonic fingerprint chip 100 is located in response to the automatic image acquisition conditions; and then determine whether the preset image acquisition conditions are met based on the current temperature. The preset image acquisition conditions are used to indicate that the number of background images obtained at the current temperature has not reached the standard. The background image is an ultrasonic image without fingerprints acquired by the ultrasonic fingerprint chip 100; and then, when the preset image acquisition conditions are met, the ultrasonic fingerprint chip 100 performs ultrasonic image acquisition, thereby effectively obtaining at least one target background image at the current temperature. Therefore, on the one hand, the technical solution in this application embodiment is not limited to acquiring the background image at the moment the finger is lifted, but can automatically acquire the current temperature after the automatic image acquisition conditions are met, and realize the automatic acquisition of the background image at the current temperature when the current temperature meets the preset image acquisition conditions. In this way, the automatically acquired background image will be more likely to be the background image within a period of time before and after the non-pressing time, that is, the situation of acquiring background images with foreign objects or residual fingerprints is reduced. Therefore, the background image is pre-stored in the background image library, and the background image at the current temperature is used for ultrasonic fingerprint detection in the future, which can more likely ensure the effect of ultrasonic fingerprint detection. Furthermore, by automatically acquiring images and storing them in the background image library in this way, the background image library can also be greatly accelerated at various temperatures. The accumulation of background images allows the background image library to be built more quickly, which is beneficial for the normal use of the ultrasonic fingerprint chip 100 in fingerprint detection under various temperature environments. On the other hand, since the ultrasonic image acquisition is only performed when the current temperature meets the preset image acquisition conditions (that is, when the number of background images obtained at the current temperature is insufficient) in this embodiment, so as to obtain at least one target background image, unnecessary image acquisition operations can be effectively avoided when there are enough background images at the current temperature. It can also ensure that a sufficient number of background images at the current temperature can be acquired for subsequent use, thereby improving the background image acquisition performance at the current temperature while effectively reducing the power consumption of the ultrasonic fingerprint chip 100.

[0087] In some optional embodiments, at least one first target background image obtained in step S106 can be used to update the background image library storing background images, wherein the first target background image is a target background image that meets preset image quality conditions.

[0088] In some technical solutions of this application embodiment, at least one target background image can be first subjected to image quality screening to select a first target background image that meets preset image quality conditions. This first target background image is then updated to the background image library for use in subsequent ultrasonic fingerprint detection. It should be understood that by updating the background image library with the first target background image that meets the preset image quality conditions, the overall image quality of the background images in the library can be ensured to be good, thereby further improving the detection performance and accuracy of subsequent ultrasonic fingerprint detection using the background image.

[0089] For example, by setting preset image quality conditions, it can be determined whether the acquired background image is clean enough, and the first target background image can be selected to ensure that the background images stored in the background image library are free from foreign objects or residual fingerprints. Those skilled in the art can flexibly set the specific content of the preset image quality conditions according to actual image quality requirements, and this application embodiment does not limit this. In some examples, the preset image quality conditions can be selected from image quality conditions related to at least one of sharpness, brightness, and contrast.

[0090] In some optional embodiments, the background image statistics corresponding to the target screen protector state can be updated based on the first target background image, wherein the target screen protector state is the same as the current screen protector state.

[0091] Optionally, if the background image statistics can be a statistical histogram, then the statistical histogram corresponding to the target film application state can be updated based on the first target background image.

[0092] Taking the statistical histogram of background image statistics as an example, in this embodiment of the application, after updating the first target background image that meets the image quality standard (i.e., meets the preset image quality conditions) to the background image library, the statistical histogram corresponding to the target film application state can be updated synchronously. Thus, the statistical histogram can reflect the latest statistical distribution of the number of each background image corresponding to the target film application state at each target temperature, ensuring the consistency and accuracy of the data in the background image library and the statistical histogram. This makes the record image re-determined based on the updated statistical histogram more accurate and reliable, which can improve the accuracy of subsequent preset image acquisition condition judgment and effectively improve the performance of background image acquisition.

[0093] Optionally, the processes of determining, maintaining, and updating the recording image, and maintaining and updating the statistical histograms of each film application state, in the embodiments of this application, can be implemented by the main control unit 410 of the electronic device 400. The electronic device 400 can configure the determined recording image to the ultrasonic fingerprint chip 100 so that the ultrasonic fingerprint chip 100 can use it in a timely manner. Transferring this part of the process to the main control unit 410 has the advantage of reducing the data processing and management pressure on the ultrasonic fingerprint chip 100, allowing the ultrasonic fingerprint chip 100 to focus more on ultrasonic image acquisition and ultrasonic fingerprint detection functions. Of course, in other embodiments, if the computing power of the ultrasonic fingerprint chip 100 is sufficient, the ultrasonic fingerprint chip 100 can also implement the processes of determining, maintaining, and updating the recording image, and maintaining and updating the statistical histograms of each film application state; or, the ultrasonic fingerprint chip 100 and the main control unit 410 can each implement a part of the process. As long as the requirements are met, this application does not impose a unique limitation on this.

[0094] Optionally, based on the current temperature collected by the temperature sensor 200 directly connected to the ultrasonic fingerprint chip 100 as described above, in some optional embodiments, step S106 may include: if the preset image acquisition conditions are met, sending an interrupt signal to the main control unit 410 of the electronic device 400 so that the ultrasonic fingerprint chip 100 performs ultrasonic image acquisition under the control of the main control unit 410 in response to the interrupt signal.

[0095] As explained earlier, the ultrasonic fingerprint chip 100 can be directly electrically connected to the temperature sensor 200. This allows the ultrasonic fingerprint chip 100 to acquire the current temperature collected by the temperature sensor 200 with low latency and power consumption, and enables direct acquisition without the need for the main control unit 410 of the electronic device 400, thus ensuring the real-time performance and accuracy of the current temperature acquisition. For example, in some implementations, the temperature sensor 200 and the ultrasonic fingerprint chip 100 can be integrated into the ultrasonic fingerprint module 300, which can ensure the efficiency of temperature data transmission.

[0096] In this embodiment, the ultrasonic fingerprint chip 100 can send an interrupt signal to the main control unit 410 of the electronic device 400 after the current temperature meets the preset image acquisition conditions. Upon receiving the interrupt signal, the main control unit 410 can respond to it and control the ultrasonic fingerprint chip to perform the ultrasonic image acquisition process, thereby acquiring a target background image at the current temperature. It is understood that at the current temperature acquired by the temperature sensor 200, the ultrasonic fingerprint chip 100 can initiate the aforementioned interrupt signal without relying on active user operation. This allows the main control unit 410 to quickly control the ultrasonic fingerprint chip 100 to achieve ultrasonic image acquisition, thus automating the background image acquisition process and helping to continuously and rapidly supplement and improve the background image library without the user's awareness.

[0097] Based on this, in this embodiment, by directly connecting the temperature sensor 200 to the ultrasonic fingerprint chip 100 and interrupting the connection, the ultrasonic fingerprint chip 100 can actively sense the current temperature and determine whether ultrasonic image acquisition is needed. When image acquisition is needed (i.e., when the preset image acquisition conditions are met), it actively sends an interrupt signal to the main control unit 410 so that the main control unit 410 can control the ultrasonic image acquisition. This effectively realizes the automatic acquisition of the background image of the current temperature without the user's active operation. Therefore, the automatically acquired background image is more likely to be the background image within a certain period before and after the non-pressing time, which can effectively reduce the probability of foreign objects or residual fingerprints in the background image, improve the quality of the acquired background image, and greatly accelerate the establishment and updating speed of the background image library. This is beneficial to the normal use of the ultrasonic fingerprint chip in fingerprint detection under various temperature environments and improves the ultrasonic fingerprint detection effect.

[0098] Figure 7 A flowchart illustrating an example of triggering ultrasonic image acquisition via an interrupt signal is shown. (Refer to...) Figure 7As shown, the recording image (e.g., in bitmap form) can be determined first; then a timer is started; the timer expires (i.e., the preset time interval is reached), which satisfies the automatic image acquisition time condition; then the ultrasonic fingerprint chip 100 acquires the current temperature collected by the temperature sensor 200. If the target value corresponding to the target temperature is determined from the recording image, and the target value is the first value (e.g., 0), then the current temperature meets the preset image acquisition condition. The ultrasonic fingerprint chip 100 sends an interrupt signal to notify the main control unit 410 of the electronic device 400, so that the main control unit 410 can respond to the interrupt signal to control the ultrasonic fingerprint chip 100 to perform ultrasonic image acquisition and obtain the background image; if the target value is not the first value (e.g., the second value 1), then the current temperature does not meet the preset image acquisition condition, and the timeout is repeated to wait for the next acquisition of the current temperature and the judgment of the target value. It should be understood that... Figure 7 The workflow shown is merely an optional example and is not intended to limit any aspect of the embodiments of this application.

[0099] It is understood that the above-described technical solution of this application embodiment is not limited to acquiring a background image at the moment the finger is lifted. Instead, it can automatically acquire the current temperature after the automatic image acquisition conditions are met, and automatically acquire a background image at the current temperature when the current temperature meets the preset image acquisition conditions. In this way, the automatically acquired background image will be more likely to be a background image within a certain period before and after the non-pressing time. That is, it reduces the possibility of acquiring a background image containing foreign objects or residual fingerprints. Therefore, pre-storing the background image in the background image library and subsequently using the background image at the current temperature for ultrasonic fingerprint detection can more likely ensure the effectiveness of ultrasonic fingerprint detection. Furthermore, by automatically acquiring and storing images in the background image library in this way, the background image library can be greatly accelerated at various temperatures. The accumulation of background images at different temperatures allows the background image library to be built up more quickly, which is beneficial for the normal use of the ultrasonic fingerprint chip 100 in fingerprint detection under various temperature environments. On the other hand, since the ultrasonic image acquisition is only performed when the current temperature meets the preset image acquisition conditions (that is, when the number of background images obtained at the current temperature is insufficient) in this embodiment, so as to obtain at least one target background image, unnecessary image acquisition operations can be effectively avoided when there are enough background images at the current temperature. This ensures that a sufficient number of background images at the current temperature can be acquired for subsequent use, thereby improving the background image acquisition performance at the current temperature while effectively reducing the power consumption of the ultrasonic fingerprint chip 100.

[0100] According to a second aspect of the embodiments of this application, an ultrasonic fingerprint chip 100 is provided for performing an ultrasonic image acquisition method as described in any of the first aspects.

[0101] According to a third aspect of the embodiments of this application, an ultrasonic fingerprint module 300 is provided. (See also...) Figure 2 As shown, the ultrasonic fingerprint module 300 may include an ultrasonic fingerprint chip 100 and a temperature sensor 200, as described in the second aspect. The temperature sensor 200 is electrically connected to the ultrasonic fingerprint chip 100 and is configured to collect the current temperature of the environment in which the ultrasonic fingerprint chip 100 is located and transmit the current temperature to the ultrasonic fingerprint chip 100.

[0102] According to a fourth aspect of the embodiments of this application, an electronic device 400 is provided. (Refer to...) Figure 8 As shown, the electronic device 400 may include: an ultrasonic fingerprint module 300 as described in the third aspect.

[0103] Optionally, refer to Figure 8 As shown, the electronic device 400 also includes a main control unit 410. The main control unit 410 can be electrically connected to the ultrasonic fingerprint chip 100 of the ultrasonic fingerprint module 300. Optionally, the electronic device 400 also includes a screen, which is configured to be able to apply a protective film, and the ultrasonic fingerprint module 300 can be disposed below the screen. For example, the ultrasonic fingerprint chip 100 of the ultrasonic fingerprint module 300 can be adhered to the underside of the screen via an adhesive layer.

[0104] It should be noted that the ultrasonic fingerprint chip 100, ultrasonic fingerprint module 300, and electronic device 400 have been described in the previous text and can be understood by referring to the previous embodiments, so they will not be repeated here.

[0105] According to the fifth aspect of the embodiments of this application, an ultrasonic fingerprint detection method is provided, referring to... Figure 9 The flowchart shown illustrates that the ultrasonic image acquisition method may include the following steps S902, S904, and S906, specifically: S902: Obtain the ultrasonic fingerprint image acquired by the ultrasonic fingerprint chip.

[0106] For example, the ultrasonic fingerprint chip 100 can be located below the screen of the electronic device 400. When the user's finger is pressed on the corresponding fingerprint detection area on the screen, the ultrasonic fingerprint chip 100 can capture the ultrasonic fingerprint image of the finger.

[0107] S904: Obtain a background image from the background image library that matches the temperature at which the ultrasonic fingerprint image was acquired.

[0108] In this embodiment of the application, at least one background image in the background image library is a target background image acquired by an ultrasonic acquisition method as described in any of the first aspects.

[0109] Optionally, during ultrasonic fingerprint image acquisition, the temperature can be acquired by the temperature sensor 200, and a background image without fingerprints that matches that temperature can be obtained from a background image library. Here, the background image matching the temperature at which the ultrasonic fingerprint image was acquired can refer to a background image in the background image library whose acquisition temperature is closest to or the same as the temperature at which the ultrasonic fingerprint image was acquired. Since the acoustic characteristics of the ultrasonic fingerprint chip 100 change with temperature, subtracting the temperature-matching background image from the ultrasonic fingerprint image can reconstruct a clear fingerprint image.

[0110] Optionally, the temperature-matched background image obtained from the background image library can be a background image that meets the preset image quality conditions (such as the aforementioned first target background image), thereby improving the ultrasonic fingerprint detection effect.

[0111] S906: Perform ultrasonic fingerprint detection based on ultrasonic fingerprint images and matching background images.

[0112] For example, a clear fingerprint image can be obtained by subtracting the matching background image from the ultrasonic fingerprint image (i.e., performing a difference calculation between the two). Based on this clear fingerprint image, a more accurate ultrasonic fingerprint detection can be performed. For instance, during ultrasonic fingerprint detection, the clear fingerprint image can be compared with a pre-stored fingerprint template, and the detection result can be determined based on the comparison result. Further optionally, based on the detection result of the ultrasonic fingerprint detection (or fingerprint recognition result), functions including but not limited to device unlocking and payment can be implemented.

[0113] In some optional embodiments, the above-described ultrasonic fingerprint detection method can be executed by the ultrasonic fingerprint chip 100, or by the main control unit 410 of the electronic device 400, or by both (i.e., each of them executes a part), as long as the requirements are met. There is no unique limitation in this embodiment of the application.

[0114] It should be understood that the ultrasonic fingerprint detection scheme of steps S902 to S906 in the embodiments of this application can use background images without fingerprints that can be obtained from a background image library, and at least one background image in the background image library is a target background image acquired by the ultrasonic acquisition method as described in the first aspect. Therefore, during ultrasonic fingerprint detection, it is more likely to use background images with good image quality and no foreign objects or residual fingerprints. Based on such background images and ultrasonic fingerprint images, ultrasonic fingerprint detection can be performed, which can effectively improve the effect and recognition success rate of ultrasonic fingerprint detection, thereby improving the performance of the ultrasonic fingerprint chip 100. In addition, it can also better adapt to the normal use requirements of ultrasonic fingerprint detection in various temperature environments.

[0115] According to a sixth aspect of the embodiments of this application, the embodiments of this application also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method as described in any one of the first and fifth aspects above. Optionally, the computer storage medium includes, but is not limited to, compact disc read-only memory (CD-ROM), random access memory (RAM), floppy disk, hard disk, or magneto-optical disk, etc.

[0116] According to the seventh aspect of the embodiments of this application, the embodiments of this application also provide a computer program product, which includes a computer program that, when executed by a processor, implements the method as described in any one of the first and fifth aspects above.

[0117] The computer storage medium and computer program product embodiments in this application have been described in detail in the foregoing embodiments. Therefore, their related content and beneficial effects can be understood by referring to the above embodiments, and will not be repeated here.

[0118] 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 application 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.

[0119] It should be noted that, depending on the implementation needs, the various components / steps described in the embodiments of this application can be broken down into more components / steps, or two or more components / steps or parts of the operations of components / steps can be combined into new components / steps to achieve the purpose of the embodiments of this application. It should be understood that the various technical features in the technical solutions of the embodiments of this application can be combined and / or broken down in any suitable manner. It should be noted that, for the convenience of explaining the embodiments of this application, the various drawings of the embodiments of this application are not necessarily drawn to scale, and are only used to facilitate the explanation of the technical solution, and are not intended to limit the embodiments of this application in any way.

[0120] The methods described in the embodiments of this application 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 subsequently 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 executing the methods shown herein.

[0121] 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 of this application.

[0122] The above embodiments are only used to illustrate the embodiments of this application, and are not intended to limit the embodiments of this application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of this application. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of this application, and the patent protection scope of the embodiments of this application should be defined by the claims.

[0123] 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 application 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 application are illustrative rather than 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".

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them; although the embodiments of this application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these 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 application.

Claims

1. A method for acquiring ultrasonic images, comprising: In response to meeting the automatic image acquisition conditions, the current temperature of the environment in which the ultrasonic fingerprint chip is located is obtained; Based on the current temperature, determine whether the preset image acquisition conditions are met, wherein the preset image acquisition conditions are conditions used to indicate that the number of background images obtained at the current temperature has not reached the standard, and the background images are ultrasonic images without fingerprints acquired by the ultrasonic fingerprint chip; If the preset image acquisition conditions are met, the ultrasonic fingerprint chip performs ultrasonic image acquisition to obtain at least one target background image of the current temperature.

2. The method according to claim 1, wherein, The step of determining whether the preset image acquisition conditions are met based on the current temperature includes: Obtain a recording image, wherein the recording image includes multiple sites, each site corresponding to a multiple target temperature within a predetermined temperature range, and the value assigned to the site is used to indicate the status of the number of background images at the corresponding target temperature meeting the standard. Based on the current temperature, obtain the target value of the site corresponding to the target temperature that matches the current temperature from the recording image; Based on the target value, determine whether the preset image acquisition conditions are met.

3. The method according to claim 2, wherein, The acquisition of the record image includes: acquiring a record image in bitmap form, wherein the assignment of the position in the record image in bitmap form includes different first values ​​and second values; The step of determining whether the preset image acquisition conditions are met based on the target assignment includes: if the target assignment is determined to be a first value, then the preset image acquisition conditions are met; otherwise, if the target assignment is determined to be a second value, then the preset image acquisition conditions are not met.

4. The method according to claim 3, wherein, The ultrasonic fingerprint chip is located below the screen, and the screen is configured to be able to be covered with a screen protector. The recording diagram is determined in the following way: Obtain background image statistics for at least one film application state, wherein the background image statistics are used to indicate the statistical distribution of the number of each background image corresponding to the film application state at each target temperature in the background image library; The recording image is determined based on the background image statistical information.

5. The method according to claim 4, wherein, The step of obtaining background image statistical information corresponding to at least one film application state includes: Obtain a statistical histogram corresponding to at least one film application state, wherein the statistical histogram is divided by each target temperature to count the number of background images corresponding to each target temperature; Determining the recorded image based on the background image statistical information includes: For each target temperature within a predetermined temperature range, the number of targets in the background image corresponding to the target temperature in the statistical histogram corresponding to each film application state is determined. Based on the determined number of targets and the preset number threshold condition, values ​​are assigned to the sites in the record image to be assigned values ​​that correspond to the target temperature. After assigning values ​​to each point corresponding to the target temperature in the record map to be assigned values, the record map is obtained.

6. The method according to claim 5, wherein, The process of assigning values ​​to the sites corresponding to the target temperature in the record graph based on a determined number of targets and a preset threshold condition includes: When at least one target quantity is less than a preset quantity threshold corresponding to the target temperature, the position in the record to be assigned value corresponding to the target temperature is assigned a first value; or... When the number of each target is greater than or equal to the preset number threshold corresponding to the target temperature, the position corresponding to the target temperature in the record to be assigned a value is assigned a second value.

7. The method according to claim 5, wherein, At least one first target background image is used to update a background image library storing background images, wherein the first target background image is a target background image that meets a preset image quality condition; Furthermore, the statistical histogram corresponding to the target screen protector state is updated based on the first target background image, wherein the target screen protector state is the same as the current screen protector state.

8. The method according to claim 4, wherein, When a preset state is met, at least one of the background image statistics is reset; The preset states include at least one of the following: the screen protector has changed, the background image library file is corrupted, or the configuration file of the ultrasonic fingerprint chip has been updated.

9. The method according to any one of claims 1-8, wherein, The step of obtaining the current temperature of the environment in which the ultrasonic fingerprint chip is located includes: obtaining the current temperature collected by a temperature sensor directly connected to the ultrasonic fingerprint chip; The step of causing the ultrasonic fingerprint chip to perform ultrasonic image acquisition if the preset image acquisition conditions are met includes: sending an interrupt signal to the main control unit of the electronic device if the preset image acquisition conditions are met, so that the ultrasonic fingerprint chip performs ultrasonic image acquisition under the control of the main control unit in response to the interrupt signal.

10. An ultrasonic fingerprint chip for performing the method as described in any one of claims 1-9.

11. An ultrasonic fingerprint module, comprising: The ultrasonic fingerprint chip and temperature sensor as described in claim 10; wherein, The temperature sensor is electrically connected to the ultrasonic fingerprint chip and is configured to collect the current temperature of the environment in which the ultrasonic fingerprint chip is located, and transmit the current temperature to the ultrasonic fingerprint chip.

12. An electronic device, comprising: The ultrasonic fingerprint module as described in claim 11.

13. An ultrasonic fingerprint detection method, comprising: Obtain an ultrasonic fingerprint image acquired by an ultrasonic fingerprint chip; A background image matching the temperature at which the ultrasonic fingerprint image was acquired is obtained from a background image library, wherein at least one background image in the background image library is a target background image acquired by the method as described in any one of claims 1-9; Ultrasonic fingerprint detection is performed based on the ultrasonic fingerprint image and the matching background image.

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 1-9 and 13.

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 1-9 and 13.

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