Patent Description:
With the development of terminal devices and user demands, the fingerprint sensor has become a common module for existing terminal devices. It is increasingly popular to initiate unlocking of a terminal device by identifying fingerprint on display (FOD). Existing screen fingerprint identification typically determines whether to unlock the terminal by analyzing a two-dimensional image.

<CIT> disclsoes a method for authenticating user of vehicle i.e. car, using millimeter-wave radar, involves authorizing user based on whether fingerprint signature matches authorized fingerprint signature of database.

<CIT> discloses a method for sensing including: transmitting electromagnetic waves between <NUM> and <NUM> to an object; receiving reflected electromagnetic waves from the object; analyzing the electromagnetic waves and reflected electromagnetic waves to determine a characteristic of interest associated with the object.

<CIT> describes techniques for using, and systems for enabling, seamless authentication using radar. Using a radar-based authentication system, the systems and techniques enable devices to sense a person in the area of the device. Once a person is determined to be near the device, the techniques and systems are capable of using radar or other sensors to authenticate the user and grant access to the device, without active and explicit input from the person.

The present disclosure provides a method for fingerprint identification, a terminal device, and a storage medium.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate examples consistent with the disclosure and, together with the description, serve to explain the principles of the disclosure.

The implementations set forth in the following description do not represent all implementations consistent with the disclosure. Instead, they are merely examples of apparatuses and methods consistent with aspects related to the invention as recited in the appended claims.

With the development of terminal devices and user demands, the fingerprint sensor has become a common module for existing terminal devices. It is increasingly popular to initiate unlocking of a terminal device by identifying fingerprint on display (FOD). Existing screen fingerprint identification typically determines whether to unlock the terminal by analyzing a two-dimensional image. However, the unlocking solution based on the two-dimensional image has a problem of poor accuracy in the image identification for unlocking.

<FIG> is a flowchart showing a method for fingerprint identification, according to an example of the present disclosure. As shown in <FIG>, the method is applied to a terminal device and includes following steps S101-S103.

In step S101, a radar wave is transmitted and a returned radar wave is received, with a radar sensor of the terminal device.

In step S102, a radar wave characteristic is acquired, according to the transmitted radar wave and the returned radar wave that is received.

In step S103, in response to determining from the radar wave characteristic that a living finger is detected in a radar emission region of the radar sensor, a fingerprint is acquired based on the fingerprint sensor of the terminal device, and the acquired fingerprint is identified for unlocking of the terminal device.

The aforementioned terminal device is a terminal device provided with a fingerprint sensor and a radar sensor. The step of the terminal device transmitting radar wave and receiving the returned radar wave with the radar sensor, includes that the terminal device transmits the radar wave with the radar sensor to an object being detected in a fingerprint identification region, and receives the retuned radar wave from the object being detected.

It is to be noted that the fingerprint identification region is an area in which the object being detected is be identified by the fingerprint sensor. The position of the fingerprint identification region may be set according to an orientation of an acquisition surface of the fingerprint sensor. For example, when the acquisition surface of the fingerprint sensor faces a screen, the fingerprint identification region may be disposed on the screen; when the acquisition surface of the fingerprint sensor faces a back shell, the fingerprint identification region may be disposed on the back shell. The object being detected may include a finger, the finger may be a thumb, a middle finger, or a ring finger, which is not limited in the present disclosure.

In the example of the present disclosure, after receiving the returned radar wave, the terminal device may acquire a radar wave characteristic according to the transmitted radar wave and the returned radar wave that is received.

The radar wave characteristic may include, but is not limited to, a radar wave coverage area characteristic, a distance characteristic, a velocity characteristic, and an angular characteristic.

The distance characteristic may be determined according to transmission time of the radar wave, reception time of the returned radar wave, and propagation speed of the radar wave. The velocity characteristic may be determined according to a difference between a transmission frequency of the radar wave and a reception frequency of the returned radar wave. The angular characteristic may be determined according to a phase change of the returned radar wave. The radar wave coverage area characteristic may be determined according to the set position of the radar wave, a transmitting range of the radar wave and a receiving range of the radar wave.

In the example of the present disclosure, an attitude change of the object being detected within a preset time period may be determined according to the distance characteristic, the velocity characteristic, and the angular characteristic. Based on the angular characteristic and the radar wave coverage area characteristic, a shape characteristic and a shape change characteristic of the radar wave may be determined. As such, the characteristic estimated based on the radar wave characteristic may be used to represent whether the object being detected is in a stationary state or whether the shape of the object being detected conforms to a shape of a finger; thus, it is determined whether the object being detected is a living finger according to the radar wave characteristic.

It is to be noted that the attitude change characteristic of the object being detected includes a relative movement distance of the object being detected, a relative movement speed of the object being detected, and a movement direction of the object being detected, which is not limited in the present disclosure.

In some examples, the step of acquiring the radar wave characteristic according to the transmitted radar wave and the returned radar wave that is received, may include: performing time-frequency processing on the radar wave and the returned radar wave to acquire the radar wave characteristic. Here, the radar wave characteristic may include at least one of the following: a shape characteristic of an object being detected in the radar emission region determined based on the returned radar wave, or an attitude change characteristic within a preset time period.

The fingerprint identification region may be in the radar emission region, and a size of the radar emission region may be larger than that of the fingerprint identification region. As such, the radar sensor can better transmit the radar wave to the object being detected disposed in the fingerprint identification region.

The time-frequency processing may include time-domain processing and frequency-domain processing. After the time-frequency processing, a range Doppler spectrum, a range spectrum, a Doppler spectrum and an angular spectrum can be obtained. The radar wave characteristic of the object being detected in the preset time period may be determined by the range Doppler spectrum, the range spectrum, the Doppler spectrum, and the angular spectrum.

The preset time period may include a time corresponding to a fixed frame length, and the fixed frame length may be set according to actual conditions. For example, the fixed frame length may be set to <NUM> frames or <NUM> frames, which is not limited in the present disclosure.

In the example of the present disclosure, it is determined whether the object being detected is a living finger according to the shape characteristic or the attitude change characteristic of the object being detected. In some examples, whether the object being detected is of a finger shape is determined according to the shape characteristic; and whether the object being detected is a living body is determined according to the attitude change characteristic.

Therefore, it can be determined whether the object being detected is a living body of a finger based on the shape characteristic or the attitude change characteristic; and the object being detected can further be identified before the fingerprint acquisition. Therefore, unlocking caused by unintended touch of a non-finger prosthesis can be reduced effectively, and accuracy of the fingerprint unlocking of the terminal device can be improved.

Here, the step of determining whether the object being detected is of the finger shape according to the shape characteristic, may include: determining a shape of the object being detected according to the shape characteristic; in response to the shape of the object being detected matching a preset shape, determining that the shape of the object being detected is a finger shape. The finger shape may include at least one of the following: a thumb shape, a middle finger shape, or a ring finger shape, which is not limited in the present disclosure.

An attitude change of the object being detected can be determined according to the attitude change characteristic of the object being detected, and whether the object being detected is a living body can be further determined based on the detected attitude change. Here, the attitude change of the object being detected may include, but is not limited to, a displacement change of the object being detected, a velocity change of the object being detected, or an angular change of the object being detected. For example, when it is detected that the displacement change and the velocity change within a preset time period are within a preset threshold range, it indicates that the movement of the object being detected is coherent; and then it can be determined that the object being detected is a living body rather than a prosthesis.

In the example of the present disclosure, it can be determined whether the object being detected is a living body or a prosthesis directly by detecting whether the object has an attitude change. For example, the one with the attitude change may be a living body, while the one without the attitude change may be a prosthesis.

Further, the terminal device may further determine that the object being detected is a living body when the attitude change of the object being detected meets a preset condition.

It is to be noted that the preset condition may include a preset movable angular range. The living finger has a movable angular range; and when the movable angle of the object being detected is not within the movable angular range, it can be determined that the object being detected is a prosthesis.

For example, the movable angle of the living finger may range from <NUM> to <NUM> degrees. When the movable angle of the object being detected is <NUM> degrees, it may be determined that the object being detected is a prosthesis. When the movable angle of the object being detected is <NUM> degrees, it may be determined that the object being detected is a living body.

In the example of the present disclosure, the living finger has a movable joint, and the angle between two portions connecting the movable joint can be relatively changed. For example, when the living finger is rotated <NUM> degrees, the angle between the two portions of the movable joint can be changed from <NUM> degrees to <NUM> degrees, while the prosthetic finger, such as a plastic finger, does not have a relative angular change when rotated <NUM> degrees. Thus, the preset condition may also include whether there is a relative angular change. When there is a relative angular change for the two portions of the object being detected, it may be determined that the object being detected is a living body. When there is not a relative angular change for the two portions of the object being detected, it may be determined that the object being detected is a prosthesis.

Therefore, based on the movable angle of the object being detected and the relative angle change of the object being detected, the prosthesis can further be ruled out effectively, and the accuracy of living body detection can be improved.

In the example of the present disclosure, the radar wave characteristic may include, in addition to the shape characteristic and the attitude change characteristic of the object being detected, a contact area characteristic of the object being detected, which is not limited in the present disclosure.

In some examples, the terminal device may further determine whether the object being detected is a finger according to the contact area characteristic, or determine whether the object being detected is a finger according to the shape characteristic and the contact area characteristic, which is not limited in the examples of the present disclosure.

In some examples, as shown in <FIG>, when it is determined from the radar wave characteristics that the living finger is detected in the radar emission region of the radar sensor, the fingerprint may be acquired with the fingerprint sensor of the terminal device, and the acquired fingerprint may be identified for unlocking of the terminal device. That is, the step S103 may include the following steps.

In step S103a, in response to determining from the radar wave characteristic that the living finger is detected in the radar emission region of the radar sensor, the fingerprint sensor of the terminal device is awakened;
In step S103b, the fingerprint is acquired with the awakened fingerprint sensor, and the acquired fingerprint is identified for unlocking of the terminal device.

In the example of the present disclosure, in order to reduce power consumption generated by the fingerprint sensor, the fingerprint sensor may be in a sleep state during the unlocking process of the terminal device. When a living finger is detected, firstly the fingerprint sensor of the terminal device is awakened. Thus, the system power consumption increasement due to awakening of the fingerprint acquisition module by unintended touch is reduced. Therefore, the power consumption of the terminal device with the fingerprint unlocking function can be effectively saved, and the use time of the terminal device can be prolonged.

In some examples, the terminal device may further include controlling the fingerprint sensor to be in a sleep state, when no living finger is detected.

It is to be noted that when no living finger is detected, it may indicate that the terminal device is touched unintendedly. For example, there may be an unintended touch caused by the terminal device being placed in a pocket, or an unintended touch caused by non-finger touching in the fingerprint identification region of a screen of a handheld terminal device. In this case, the fingerprint sensor does not need to perform fingerprint identification, and the terminal device does not need to awaken the fingerprint sensor in the sleep state.

As such, according to the example of the present disclosure, by controlling the fingerprint sensor to be in the sleep state when no living finger is detected, the power consumption increasement due to awakening of the terminal device by unintended touch of the terminal device is reduced. Therefore, the power consumption of the terminal device can be effectively saved, and the use time of the terminal device can be prolonged.

In the example of the present disclosure, the step of controlling the fingerprint sensor to be in the sleep state when no living finger is detected, may include:.

That is, according to the example of the present disclosure, an operation state of the fingerprint sensor may be determined in advance. When the operation state of the fingerprint sensor is the sleep state and no living body is detected, the fingerprint sensor may be not awakened, so that the fingerprint sensor may continue to remain in the sleep state. When the operation state of the fingerprint sensor is the awakened state and no living body is detected, the fingerprint sensor may be controlled to switch from the awakened state to the sleep state. As described above, in the example of the present disclosure, the fingerprint sensor can be controlled flexibly to enter the sleep state from a different state when a living finger is detected, thus reducing the power consumption of the terminal device and prolonging the use time of the terminal device.

In the example of the present disclosure, after awakening the fingerprint sensor of the terminal device, the fingerprint may be acquired with the awakened fingerprint sensor, and the acquired fingerprint may be identified for unlocking of the terminal device. The process of the fingerprint sensor acquiring the fingerprint may include: transmitting light to the object being detected and receiving reflected light that is returned, and forming a fingerprint image based on the reflected light, thus realizing identification of the fingerprint for unlocking of the terminal device.

The fingerprint sensor can realize the unlocking of the terminal device by identifying the fingerprint in the identification region in the screen of the terminal device, and the fingerprint sensor can also realize the unlocking of the terminal device by identifying the fingerprint in the identification region on the back shell of the terminal device, which is not limited in the example of the present disclosure.

In the example of the present disclosure, the unlocking process of the terminal device may include: when the acquired fingerprint matches a fingerprint template input to the terminal device, unlocking the terminal device; when the acquired fingerprint does not match the fingerprint template input to the terminal device, the terminal device continuing to be in the locking state. Thus, the fingerprint unlocking process of the terminal device can be realized by comparing the acquired fingerprint with the fingerprint template.

It is to be noted that, according to the example of the present disclosure, the radar wave characteristic may be acquired based on the returned radar wave received with the radar sensor, and it may be determined whether a living finger is detected based on the radar wave characteristic. And then, the fingerprint sensor may be awakened to acquire a fingerprint, in response to determining that the living finger is detected. That is, in the example of the present disclosure, before the fingerprint sensor acquiring the fingerprint; it is firstly determined whether the living finger is detected in a radar emission region, rather than performing fingerprint acquisition on any object being detected. Therefore, by detecting the living finger, unlocking caused by unintended touch of a non-finger prosthesis is reduced effectively, and accuracy of the fingerprint unlocking is improved. In addition, since the fingerprint sensor is awakened when the living finger is detected, the system power consumption increasement due to awakening of the fingerprint acquisition module by unintended touch is reduced. Therefore, the power consumption of the terminal device can be effectively saved with the fingerprint unlocking function, and the use time of the terminal device can be prolonged.

In some examples, the step of determining according to the radar wave characteristic that the living finger is detected in the radar emission region of the radar sensor may include:.

In the example of the present disclosure, the terminal device may store a living finger identification model in advance. And after acquiring the radar wave characteristic, the terminal device may perform matching based on the living finger identification model, and further determine whether the living finger is detected.

It is to be noted that the living finger identification model may be constituted by a plurality of sub-models corresponding to different fingers, and the plurality of sub-models are capable of detecting whether a different object being detected is a living finger according to the radar wave characteristic of the object being detected. For example, the fingers may include at least one of: a middle finger and an ring finger; the object being detected may be detected to be a living middle finger based on a sub-model corresponding to the middle finger; and the object being detected may be detected to be a living ring finger based on a sub-model corresponding to the ring finger.

In the example of the present disclosure, there may be a plurality of radar sensors, and a plurality of sets of radar wave characteristics may be acquired with the plurality of radar sensors. And then, the plurality of sets of radar wave characteristics may be input to a living finger identification model, so that a plurality of sets of matching degrees of the plurality of sets of radar wave characteristics may be acquired. According to the example of the present disclosure, after acquiring the plurality of sets of matching degrees, normalization processing may be performed on the plurality of sets of matching degrees of the plurality of sets of radar wave characteristics, and it may be further determined that the object being detected is a living finger when a normalized matching result is greater than a matching threshold.

It is to be noted that the normalization processing means normalizing the plurality of sets of matching degrees of the plurality of sets of radar wave characteristics to a fraction between <NUM> and <NUM>. The step of performing normalization processing on the plurality of sets of matching degrees of the plurality of sets of radar wave characteristics, may include: acquiring a highest matching degree and a lowest matching degree of the plurality of sets of radar wave characteristics, and determining a normalized matching result of the plurality of sets of radar wave characteristics based on the highest matching degree and the lowest matching degree.

Therefore, through determining whether the object being detected is a living finger according to the matching result acquired by the normalization processing, inaccuracy of the detection result caused by the detection error of different radar sensors can be reduced effectively, thus improving accuracy of the detection of the living finger.

For example, the matching threshold may be set according to a detection accuracy requirement for actually detecting a living finger. For example, the matching threshold may be set to <NUM> or <NUM>, or the like, which is not limited in the example of the present disclosure.

In some examples, the method may further include:.

In the example of the present disclosure, the finger identification model may be a model acquired by training characteristic samples in a finger identification scene and a classification training model.

The normal-characteristic samples may be samples acquired with a radar sensor in a scene of the living fingerprint unlocking. The abnormal-characteristic samples may be samples other than the normal-characteristic samples. Here, the abnormal-characteristic samples may be samples acquired with the radar sensor in a plurality of abnormal scenes. The abnormal scenes may include an identification scene of a non-fingerprint identification region, an identification scene of a prosthetic finger, an identification scene of a non-finger, or an identification scene of a plurality of fingers, which is not limited in the example of the present disclosure.

It is to be noted that the terminal device may have a fingerprint identification region, and the aforementioned non-fingerprint identification region may be a region other than the fingerprint identification region of the terminal device. For example, the non-fingerprint identification region may include a region in which a decorative member of a camera is disposed or a region in which a housing on the side of the terminal device is disposed.

The identification scene of the aforementioned non-fingerprint identification region may be a scene in which an object being detected acts on the non-fingerprint identification region to perform the fingerprint unlocking. When the object being detected acts on the non-fingerprint identification region, the fingerprint sensor may not acquire the fingerprint of the object being detected; thus, the fingerprint identification and unlocking may not be realized. Therefore, the identification scene of the non-fingerprint identification region may be used as an abnormal finger identification scene for fingerprint unlocking.

The identification scene of the prosthetic finger may be a scene in which the fingerprint unlocking is performed by the prosthetic finger in the fingerprint identification region. The prosthetic finger may be a finger made of plastic or silica gel.

The non-finger identification scene may be an identification scene in which a user takes a part other than a finger as the object being detected. The part other than the finger may include an elbow, a finger contact, or a stylus, which is not limited in the present disclosure.

The identification scene of the plurality of fingers may be an identification scene in which the plurality of fingers simultaneously act on the fingerprint identification region. For example, cases that the plurality of fingers simultaneously act on the fingerprint identification region may include: two fingers simultaneously acting on the fingerprint identification region, or, three fingers simultaneously acting on the fingerprint identification region, which is not limited in the present disclosure.

In the example of the present disclosure, each of the normal-characteristic sample and the abnormal-characteristic sample may include a plurality of samples, and the normal-characteristic sample and the abnormal-characteristic sample may be the samples extracted from different manually simulated scenes. Therefore, the normal-characteristic sample and the abnormal-characteristic sample can accurately represent the identification process in a real scene, and an accurate matching degree can be obtained based on the living finger identification model trained by the normal-characteristic sample and the abnormal-characteristic sample, so that the living fingerprint determined based on the matching degree can be more accurate.

For example, the classification training model may include a model formed by Convolutional Neural Network (CNN), which is not limited in the present disclosure.

In the example of the present disclosure, when the fingerprint template is input to the terminal device, the fingerprint sensor may acquire the fingerprint of the object being detected and store the detected historical fingerprint as the fingerprint template in the terminal device. After determining that the object being detected is a living finger, the terminal device may match the current fingerprint acquired with the fingerprint sensor with the fingerprint template, thus enabling the identification for unlocking of the terminal device. The fingerprint template may be a complete fingerprint, and the terminal device can be unlocked with the fingerprint template.

The terminal device may store a living finger identification model in advance. When a template fingerprint is input to the terminal device, the living identification model may be updated based on a radar template characteristic acquired with the radar sensor.

It is to be noted that a scene in which a template fingerprint is input to the terminal device may belong to a normal finger identification scene. Therefore, the radar template characteristic may belong to the normal-characteristic sample, and the radar template characteristic may be input to the living finger identification model, so that the living finger identification model can be retrained to obtain a more accurate living finger identification model.

In the example of the present disclosure, it may be determined whether the terminal device is in the state of being held with a pressure sensor and a temperature sensor of the terminal device. For example, when the pressure detected with the pressure sensor is greater than a pressure threshold, and/or, the temperature detected with the temperature sensor is greater than the temperature threshold, it may be determined that the terminal device is in the state of being held.

It is to be noted that when the terminal device is not in the state of being held, it may indicate that an unlocking behavior is a non-user behavior or an unintended-touch behavior; and when the acquired fingerprint does not match the fingerprint template, it may indicate that the unlocking behavior is a not a user behavior authenticated by the terminal device. Therefore, by refusing to unlock the terminal device when the terminal device is not in the state of being held and/or the acquired fingerprint does not match the fingerprint template, the accuracy of unlocking of the terminal device can be improved.

That is, according to the example of the present disclosure, when no living finger is detected, the fingerprint acquired with the fingerprint sensor may be discarded directly, instead of being further processed, so that the power consumption for processing the fingerprint can be reduced effectively, the power consumption of the terminal device can be saved, and the use time of the terminal device can be prolonged.

In the example of the present disclosure, when the radar sensor and the fingerprint sensor are simultaneously in an operation state, the terminal device may perform an unlocking operation when both an acquisition result obtained by the fingerprint sensor and a detection result of obtained by the radar sensor meet the requirement. Before confirming the detection result obtained by the radar sensor, the terminal device does not perform the unlocking operation even if the acquisition result obtained by the fingerprint sensor meets the requirement.

For a better understanding of the example of the present disclosure, as shown in <FIG>, a method for fingerprint identification according to the example of the present disclosure is provided, the method including the following steps.

In step S201, a radar wave is transmitted and a returned radar wave is received, with a radar sensor of the terminal device.

In step S202, a radar wave characteristic is acquired, according to the transmitted radar wave and the returned radar wave that is received.

In step S203, it is determined from the radar wave characteristic whether a living finger is detected in a radar emission region. If determining that the living finger is detected, the method proceeds to step S204; and if determining that no living finger is detected, the method proceeds back to step S201.

In step S204, the fingerprint sensor is awakened, and a fingerprint is acquired with the awakened fingerprint sensor.

In step S205, it is determined whether the acquired fingerprint matches a preset fingerprint. If determining that the acquired fingerprint matches the preset fingerprint, the method proceeds to step S206; and if determining that the acquired fingerprint does not match the preset fingerprint, the method proceeds to step S207.

In step S206, the authentication is passed, and a locking state of the terminal device is released.

In step S207, unlocking is refused, and the terminal device is still in the locking state.

It is to be noted that the prosthesis may also be identified with an ultrasonic sensor before fingerprint sensor is awakened. The ultrasonic sensor can determine the material of the object being detected from variations of the reflected ultrasonic waves of different objects being detected, thus realizing identification of the prosthesis. As shown in <FIG>, the step of identifying the prosthesis may include the following steps. In step S301, an ultrasonic characteristic is acquired with the ultrasonic sensor. In step S302, it is determined whether the ultrasonic characteristic matches an ultrasonic template characteristic. If the ultrasonic characteristic matches the ultrasonic template characteristic, the method proceeds to step S303; and if the ultrasonic characteristic does not match the ultrasonic template characteristic, the method proceeds back to step S301. In step S303, the object being detected is determined as a prosthesis. It can be seen from the identification of the prosthesis through ultrasonic that the ultrasonic sensor can identify the prosthesis, but cannot identify whether the object being detected is a finger. Therefore, there is a problem of misoperation caused by unlocking due to a non-finger identification, and there is also a case in which the power consumption of the terminal device is increased by unlocking due to a non-finger identification.

Based on this, according to the example of the present disclosure, the radar wave characteristic may be acquired based on the returned radar wave received with the radar sensor, and it is determined whether a living finger is detected based on the radar wave characteristic. And then, the fingerprint sensor is awakened to acquire a fingerprint, in response to determining that the living finger is detected. That is, in the example of the present disclosure, before the fingerprint sensor acquires the fingerprint; it is firstly determined whether the living finger is detected in a radar emission region, rather than performing fingerprint acquisition on any object being detected. Therefore, by detecting the living finger, unlocking caused by unintended touch of a non-finger or a prosthesis is reduced effectively, and accuracy of the fingerprint unlocking is improved. In addition, since the fingerprint sensor is awakened when the living finger is detected, the system power consumption increasement due to awakening of the fingerprint acquisition module by unintended touch is reduced. Therefore, the power consumption of the terminal device can be effectively saved with the fingerprint unlocking function, and the use time of the terminal device can be prolonged.

In the examples of the present disclosure, a terminal device is further provided. As shown in <FIG>, the terminal device includes:.

The terminal device may be a wearable electronic device and a mobile terminal. The mobile terminal may include a mobile phone, a notebook, and a tablet computer; and the wearable electronic device may include a smart watch, which is not limited in the example of the present disclosure.

The screen may be a screen formed of a Liquid Crystal Display (LCD), or a screen formed of an Organic Electroluminesence Display (OLED), which is not limited in the present disclosure.

In the example of the present disclosure, the terminal device may have a fingerprint identification region, which may be disposed on a screen, and an acquisition surface of the corresponding fingerprint sensor may face the screen; thus, fingerprint identification can be realized by acquiring an object being detected in the fingerprint identification region in the screen.

The fingerprint identification region may also be disposed on the back shell of the terminal device, and the acquisition surface of the corresponding fingerprint sensor may face toward the back shell; thus, the fingerprint identification can be realized based on the object being detected in the fingerprint identification area on the back shell.

In the example of the present disclosure, the orientation of the acquisition surface of the radar sensor may be the same as that of the acquisition surface of the fingerprint sensor. The radar sensor may include one or more radar sensors, which is not limited in the present disclosure.

For example, the radar sensor may include, but is not limited to, a millimeter wave radar sensor. The millimeter wave radar sensor may emit a radar wave at an extremely high frequency of <NUM> and a wavelength of <NUM> to improve detection accuracy.

It is to be noted that, the terminal device may firstly acquire the radar wave characteristic based on the returned radar wave received with the radar sensor, and determine whether a living finger is detected based on the radar wave characteristic. And then, the terminal device may awaken the fingerprint sensor to acquire a fingerprint, in response to determining that the living finger is detected. That is, in the example of the present disclosure, before the fingerprint sensor acquires the fingerprint; it is firstly determined whether the living finger is detected in a radar emission region, rather than performing fingerprint acquisition on any object being detected. Therefore, by detecting the living finger, unlocking caused by unintended touch of a non-finger or a prosthesis is reduced effectively, and accuracy of the fingerprint unlocking is improved. In addition, since the fingerprint sensor is awakened when the living finger is detected, the system power consumption increasement due to awakening of the fingerprint acquisition module by unintended touch is reduced. Therefore, the power consumption of the terminal device can be effectively saved with the fingerprint unlocking function, and the use time of the terminal device can be prolonged.

In some examples, the radar sensor may include:.

In the example of the present disclosure, the number of transmitters may be less than or equal to the number of receivers, which is not limited in the example of the present disclosure.

It is to be noted that the terminal device may be provided with a plurality of transmitters to acquire a plurality of sets of returned radar waves and a corresponding plurality of sets of radar wave characteristics, so that it can be determined more accurately whether the object being detected is a living finger based on the plurality of sets of radar wave characteristics. Moreover, according to the example of the present disclosure, a plurality of receivers can be provided to improve a reception rate of receiving the plurality of sets of returned radar waves. And further, it can be determined more accurately whether the object being detected is a living finger based on the radar wave characteristics corresponding to the plurality of sets of returned radar waves.

In some examples, as shown in <FIG>, the at least one transmitter may include two transmitters 403a disposed on opposite sides of the fingerprint sensor <NUM>; and
the at least one receiver 403b may include four receivers 403b, disposed around the fingerprint sensor <NUM> symmetrically with the fingerprint sensor <NUM> as a center.

In the example of the present disclosure, the transmitter may be disposed to be opposite to the fingerprint sensor, so that the transmitter can transmit radar waves to a the object being detected in different directions, and the corresponding radar wave characteristic can be acquired more comprehensively. Four receivers may be disposed around the fingerprint sensor symmetrically with the fingerprint sensor as a center, so that the returned radar wave from the object being detected can be received with the receivers, and the reception rate of the returned radar wave can be improved.

In some examples, as shown in <FIG>, the at least one receiver 403b may be disposed at an edge of the terminal device.

In the example of the present disclosure, the receiver may be disposed at the edge of the terminal device, so that the receiver can better receive the returned radar wave.

With regard to the terminal device in the foregoing examples, the specific manner, in which the respective module of the terminal device performing operations, has been described in detail in the foregoing examples of the method, and no detailed explanation will be elaborated here.

<FIG> is a block diagram of a terminal device according to an example. For example, the terminal device may be a mobile phone, a mobile computer, or the like.

Referring to <FIG>, the terminal device may include one or more of the following components: a processing component <NUM>, a memory <NUM>, a power component <NUM>, a multimedia component <NUM>, an audio component <NUM>, an input/output (I/O) interface <NUM>, a sensor component <NUM>, and a communication component <NUM>.

The processing component <NUM> typically controls overall operations of the terminal device, such as the operations associated with display, telephone calls, data communications, camera operations, and recording operations.

The memory <NUM> is configured to store various types of data to support the operation of the terminal device. Examples of such data include instructions for any applications or methods operated on the terminal device, contact data, phonebook data, messages, pictures, video, etc. The memory <NUM> may be implemented using any type of volatile or non-volatile memory devices, or a combination of the volatile or non-volatile memory devices, such as a static random access memory (SRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a magnetic memory, a flash memory, a magnetic or optical disk.

The power component <NUM> provides power to various components of the terminal device. The power component <NUM> may include a power management system, one or more power sources, and any other components associated with the generation, management, and distribution of power in the terminal device.

The multimedia component <NUM> includes a screen providing an output interface between the terminal device and the user. In some examples, the screen may include a liquid crystal display (LCD) and a touch panel (TP). In some examples, the multimedia component <NUM> includes a front camera and/or a rear camera. The front camera and the rear camera may receive an external multimedia datum while the terminal device is in an operation mode, such as a photographing mode or a video mode.

The audio component <NUM> is configured to output and/or input audio signals. For example, the audio component <NUM> includes a microphone ("MIC") configured to receive an external audio signal when the terminal device is in an operation mode, such as a call mode, a recording mode, and a voice identification mode. The received audio signal may be further stored in the memory <NUM> or transmitted via the communication component <NUM>. In some examples, the audio component <NUM> further includes a speaker to output audio signals.

The sensor component <NUM> includes one or more sensors to provide status assessments of various aspects of the terminal device. For instance, the sensor component <NUM> may detect an on/off status of the terminal device, relative positioning of components, e.g., the display and the keypad, of the terminal device, a change in position of the terminal device or a component of the terminal device, a presence or absence of user contact with the terminal device, an orientation or an acceleration/deceleration of the terminal device, and a change in temperature of the terminal device. In some examples, the sensor component <NUM> may also include an accelerometer sensor, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

The communication component <NUM> is configured to facilitate communication, wired or wirelessly, between the terminal device and other devices. The terminal device can access a wireless network based on a communication standard, such as Wi-Fi, <NUM>, or <NUM>, or a combination thereof. In one example, the communication component <NUM> receives a broadcast signal or broadcast associated information from an external broadcast management system via a broadcast channel. In one example, the communication component <NUM> further includes a near field communication (NFC) module to facilitate short-range communications. For example, the NFC module may be implemented based on a radio frequency identification (RFID) technology, an infrared data association (IrDA) technology, an ultra-wideband (UWB) technology, a Bluetooth (BT) technology, and other technologies.

In examples, the terminal device may be implemented with one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, micro-controllers, microprocessors, or other electronic components, for performing the above described methods.

In examples, there is also provided a non-transitory computer readable storage medium including instructions, such as the memory <NUM> including instructions, the instructions are executable by the processor <NUM> in the terminal device, to perform the above-described methods. For example, the non-transitory computer-readable storage medium may be a ROM, a CD-ROM, a magnetic tape, a floppy disc, an optical data storage device, and the like.

A non-temporary computer-readable storage medium having stored therein computer-executable instructions which, when executed by a processor, cause the processor to implement a method for fingerprint identification, and the method includes:.

Other examples of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed here. This disclosure is intended to cover any variations, uses, or adaptations of the disclosure following the general principles thereof and including such departures from the present disclosure as come within known or customary practice in the art.

Claim 1:
A method for fingerprint identification, applied to a terminal device comprising a fingerprint sensor and a radar sensor, the method comprising:
transmitting (<NUM>) a radar wave with the radar sensor to an object being detected in a fingerprint identification region of the fingerprint sensor and receiving (<NUM>) a returned radar wave with the radar sensor of the terminal device from the object being detected;
acquiring (<NUM>) a radar wave characteristic, according to the transmitted radar wave and the received returned radar wave;
determining whether the object being detected is a living finger according to the radar wave characteristic; and
in response to determining from the radar wave characteristic that the object being detected is a living finger that is detected in a radar emission region of the radar sensor, acquiring (<NUM>) a fingerprint based on the fingerprint sensor of the terminal device, and identifying (<NUM>) the acquired fingerprint for unlocking of the terminal device,
wherein acquiring the radar wave characteristic according to the transmitted radar wave and the received returned radar wave, comprises:
performing time-frequency processing on the transmitted radar wave and the returned radar wave to acquire the radar wave characteristic;
wherein the radar wave characteristic comprises:
a shape characteristic of an object being detected in the radar emission region determined based on the returned radar wave, and
an attitude change characteristic within a preset time period,
wherein determining whether the object being detected is the living finger according to the radar wave characteristic comprises:
determining whether the object being detected is of a finger shape, according to the shape characteristic; and
determining whether the object being detected is a living body, according to the attitude change characteristic, wherein the attitude change characteristic comprises at least one of a relative movement distance of the object being detected, a relative movement speed of the object being detected or a movement direction of the object being detected.