CN113168534A

CN113168534A - Device and method for detecting finger dryness and humidity and electronic equipment

Info

Publication number: CN113168534A
Application number: CN202080006668.0A
Authority: CN
Inventors: 杨小强; 叶川; 青小刚; 张珂
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2020-09-11
Filing date: 2020-09-11
Publication date: 2021-07-23
Also published as: WO2022052071A1

Abstract

An apparatus (100), method and electronic device (200) for detecting finger dryness, the apparatus (100) comprising: optical fingerprint module (110) for the reflection light that the reflection and formed takes place for the finger of receiving light illumination, in order to obtain first fingerprint image, first fingerprint image is used for obtaining the current dry humidity value that first fingerprint image corresponds, in order to confirm the dry humidity level of finger. The device (100), the method and the electronic equipment (200) can realize the detection of the finger dryness and humidity without adding extra hardware cost.

Description

Device and method for detecting finger dryness and humidity and electronic equipment

Technical Field

The embodiment of the application relates to the technical field of fingerprint identification, in particular to a device and a method for detecting finger dryness and humidity and an electronic device.

Background

In the method for measuring the skin dryness and humidity in the market, special hardware equipment is adopted to calibrate the water content of the human skin by measuring the resistivity or the dielectric constant of the skin.

For the current electronic devices, how to detect the dryness and humidity of the fingers without adding extra hardware cost is a problem to be solved.

Disclosure of Invention

The embodiment of the application provides a device and a method for detecting finger dryness and humidity and electronic equipment, which can realize the detection of the finger dryness and humidity without increasing extra hardware cost.

In a first aspect, there is provided a device for detecting finger dryness, the device comprising: the optical fingerprint module is used for receiving light and irradiating the reflected light formed by reflecting the finger so as to acquire a first fingerprint image, and the first fingerprint image is used for acquiring the current humidity value corresponding to the first fingerprint image so as to determine the humidity level of the finger.

In some possible implementations, the apparatus further includes: and the processor is used for acquiring the current dryness and humidity value according to the first fingerprint image and determining the dryness and humidity level of the finger according to the current dryness and humidity value.

In some possible implementations, the processor obtaining the current dryness fraction value according to the first fingerprint image includes: acquiring a gradient value and/or a reflected light intensity value of the first fingerprint image according to the first fingerprint image; and determining the current dry-wet value according to the gradient value and/or the reflected light intensity value.

In some possible implementations, the processor determines the current dry-wet value according to the gradient value and the reflected light intensity value, including: determining a calculation result of (w1 a + w 2B) as the current dry-wet value, wherein a is the gradient value, B is the reflected light intensity value, w1 is the weight of the gradient value, w2 is the weight of the reflected light intensity value, w1+ w2 is 1 and neither w1 nor w2 is 0.

In some possible implementations, w1 is greater than w 2.

In some possible implementations, the processor determines the dryness-humidity level of the finger according to the current dryness-humidity value, including: determining a dryness-humidity level of the finger based on a relationship between the current dryness-humidity value and at least one threshold, the at least one threshold being determined based on historical dryness-humidity values.

In some possible implementations, the processor is further configured to: acquiring a dryness-humidity histogram according to the corresponding dryness-humidity values of a plurality of historical fingerprint images, wherein the dryness-humidity histogram comprises a plurality of histograms which are used for representing the corresponding relation between the dryness-humidity values and the number of the fingerprint images; the at least one threshold is determined based on the psychrometric histogram.

In some possible implementations, the at least one threshold includes a first threshold, and the processor determines the at least one threshold based on the psychrometric histogram, including: and traversing the dryness fraction histogram from left to right, and determining the dryness fraction value at the first turning point as the first threshold, wherein the number of the fingerprint images represented by the histogram on the left side of the first turning point is in a decreasing trend, and the number of the fingerprint images represented by the histogram on the right side of the first turning point is in an increasing trend.

In some possible implementations, the processor determines the dryness fraction of the finger based on a relationship between the current dryness fraction and at least one threshold, including: if the current dryness-humidity value is less than or equal to the first threshold, determining the dryness-humidity level of the finger as a dry finger level; or if the current dry-wet value is greater than the first threshold, determining that the dry-wet level of the finger is a wet-finger level.

In some possible implementations, the processor is further configured to: and determining the dryness-humidity score of the finger according to the dryness-humidity interval corresponding to the dryness-humidity level of the finger.

In some possible implementations, the processor is further configured to: and storing the dryness fraction of the finger into a dryness fraction report, wherein the dryness fraction report comprises a plurality of historical dryness fractions.

In some possible implementations, the processor obtains gradient values of the first fingerprint image according to the first fingerprint image, including: and performing gradient operation in the horizontal direction and the vertical direction on the first fingerprint image after low-pass filtering to obtain the gradient value.

In a second aspect, there is provided a method of detecting finger dryness, the method comprising: acquiring a current dry-wet value corresponding to a first fingerprint image according to the first fingerprint image, wherein the first fingerprint image is a fingerprint image obtained by reflected light formed by reflecting light irradiating a finger; and determining the dryness-humidity level of the finger according to the current dryness-humidity value.

In some possible implementations, the obtaining, according to the first fingerprint image, a current dryness-humidity value corresponding to the first fingerprint image includes: acquiring a gradient value and/or a reflected light intensity value of the first fingerprint image according to the first fingerprint image; and determining the current dry-wet value according to the gradient value and/or the reflected light intensity value.

In some possible implementations, the determining the current dry-wet value according to the gradient value and the reflected light intensity value includes: determining a calculation result of (w1 a + w 2B) as the current dry-wet value, wherein a is the gradient value, B is the reflected light intensity value, w1 is the weight of the gradient value, w2 is the weight of the reflected light intensity value, w1+ w2 is 1 and neither w1 nor w2 is 0.

In some possible implementations, w1 is greater than w 2.

In some possible implementations, the determining the dryness-humidity level of the finger according to the current dryness-humidity value includes: determining a dryness-humidity level of the finger based on a relationship between the current dryness-humidity value and at least one threshold, the at least one threshold being determined based on historical dryness-humidity values.

In some possible implementations, the method further includes: acquiring a dryness-humidity histogram according to the corresponding dryness-humidity values of a plurality of historical fingerprint images, wherein the dryness-humidity histogram comprises a plurality of histograms which are used for representing the corresponding relation between the dryness-humidity values and the number of the fingerprint images; the at least one threshold is determined based on the psychrometric histogram.

In some possible implementations, the at least one threshold includes a first threshold, and the determining the at least one threshold from the psychrometric histogram includes: and traversing the dryness fraction histogram from left to right, and determining the dryness fraction value at the first turning point as the first threshold, wherein the number of the fingerprint images represented by the histogram on the left side of the first turning point is in a decreasing trend, and the number of the fingerprint images represented by the histogram on the right side of the first turning point is in an increasing trend.

In some possible implementations, the determining the dryness fraction of the finger according to the relationship between the current dryness fraction and at least one threshold value includes: if the current dryness-humidity value is less than or equal to the first threshold, determining the dryness-humidity level of the finger as a dry finger level; or if the current dry-wet value is greater than the first threshold, determining that the dry-wet level of the finger is a wet-finger level.

In some possible implementations, the method further includes: and determining the dryness fraction of the finger according to the dryness fraction corresponding to the current dryness fraction.

In some possible implementations, the method further includes: adding the finger's dryness fraction to a dryness fraction report, the dryness fraction report including a plurality of historical dryness fractions.

In some possible implementations, the obtaining the gradient value corresponding to the first fingerprint image according to the first fingerprint image includes: and performing gradient operation in the horizontal direction and the vertical direction on the first fingerprint image after low-pass filtering to obtain the gradient value.

In a second aspect, an electronic device is provided, comprising: an apparatus for detecting finger dryness as in the first aspect or any possible implementation manner of the first aspect.

In some possible implementations, the electronic device further includes: the display screen detects the below that the optics fingerprint module group in the device of finger dry humidity sets up at this display screen.

Drawings

Fig. 1 is a schematic block diagram of an apparatus for detecting finger dryness according to an embodiment of the present application.

Fig. 2 is another schematic block diagram of an apparatus for detecting finger dryness according to an embodiment of the present disclosure.

Fig. 3 is a schematic diagram of fingerprint image textures corresponding to fingers with different dry and wet degrees.

Fig. 4 and 5 are schematic optical path diagrams of wet and dry fingers, respectively, based on reflected light imaging.

Fig. 6 is a schematic diagram of a psychrometric histogram in an embodiment of the present application.

Fig. 7 and fig. 8 are schematic diagrams of a psychrometric report according to an embodiment of the present disclosure.

Fig. 9 is a flowchart of a technical solution for detecting finger dryness according to an embodiment of the present application.

FIG. 10A is an orientation view of an electronic device according to an embodiment of the present application.

Fig. 10B is a schematic cross-sectional view of the electronic device shown in fig. 10A along a-a'.

Fig. 11 is a schematic block diagram of a method for detecting finger dryness according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

Currently, the method for measuring the skin dryness and humidity in the market is to calibrate the water content of human skin by measuring the resistivity or dielectric constant of the skin. For current electronic devices, additional hardware may be required to implement the detection of skin dryness and wetness.

The embodiment of the application provides a scheme for detecting finger dryness and humidity, which can be realized by utilizing the hardware condition of the existing electronic equipment and is beneficial to users to know the skin state of the users.

Fig. 1 shows a schematic block diagram of an apparatus 100 for detecting finger dryness according to an embodiment of the present application. As shown in fig. 1, the apparatus 100 may include:

the optical fingerprint module 110 is configured to receive light to irradiate a finger and reflect the light to form a reflected light, so as to obtain a first fingerprint image, where the first fingerprint image is used to obtain a current humidity value corresponding to the first fingerprint image, so as to determine a humidity level of the finger.

In the embodiment of the present application, the dryness and humidity level may be classified according to the dryness and humidity level of the finger, for example, may be classified into an extremely dry finger level, an ordinary wet finger level, and an extremely wet finger level. There can also be a rough division into two levels: dry finger rating and wet finger rating. Or may be divided into more levels.

The finger's of this application embodiment humidity level can be confirmed through the fingerprint image that optics fingerprint identification module acquireed to can realize the detection of finger humidity under the condition that does not increase extra hardware cost.

The dryness fraction value in the embodiment of the present application refers to a value for characterizing the dryness fraction of the finger, for example, a reflected light intensity value of a fingerprint image, a gradient value of the fingerprint image, or a value calculated from both, which are described below.

Optionally, as shown in fig. 2, in an embodiment of the present application, the apparatus 100 may further include:

and the processor 120 is configured to obtain the current humidity value according to the first fingerprint image, and determine the humidity level of the finger according to the current humidity value.

The apparatus 100 provided in the embodiment of the present application may be a fingerprint identification apparatus, and may also be an electronic device. When the device 100 is a fingerprint recognition device, the processor 120 may be an image processor, such as a Micro Control Unit (MCU). When the apparatus 100 is an electronic device, the processor 120 may be a processor of the electronic device, such as a Central Processing Unit (CPU).

For ease of understanding, the relationship between the fingerprint image and the dryness of the finger is described next.

Generally, the sharpness of the fingerprint image texture may reflect the degree of finger dryness. As can be seen from fig. 3, the drier the skin of the finger, the more blurred the fingerprint image texture, whereas the wetter the finger, the clearer the fingerprint image texture.

In addition, dry fingers have less oil and water on the skin surface and dry skin has a more firm stratum corneum than wet skin. When a dry finger presses against the display, this can result in a finger not touching the display as well as wetting the finger. Because the formation of image of fingerprint line on fingerprint sensor chip (sensor) is according to fingerprint valley and the ridge reflection to the light intensity difference of sensor, obtains the formation of image of valley ridge, and the valley received on the sensor is big with ridge reflection light intensity difference, and the fingerprint line is more clear, and the fingerprint line is more fuzzy otherwise.

Fig. 4 and 5 show schematic diagrams of the principle of wet and dry fingers, respectively, when imaged based on reflected light.

As shown in fig. 4, it is assumed that the surface of the electronic device is a glass cover plate, and a finger contacts the surface of the glass cover plate when performing fingerprint identification, wherein, because the finger is a wet finger, a fingerprint ridge of the finger can be well contacted with the surface, and a fingerprint valley of the finger has a gap with the surface, and the gap is air.

As shown in fig. 4, it is assumed here that the light L1 irradiated to the finger through the glass cover plate is uniform. According to the law of refraction and reflection of optics, when light L1 is irradiated to a finger, the contact at the ridge line of the fingerprint is good, and the refractive index of the finger and the glass cover plate is similar, so that more light L11 is transmitted into the finger, and less reflected light L21 is transmitted into the finger; however, since there is an air gap at the valley line, and the difference between the refractive indexes of air and the glass cover plate is large, the light L12 transmitted into the finger is small, the reflected light L22 on the surface of the cover plate is large, and there may be a small portion of light L23 reflected from the surface of the fingerprint valley, so as to form a contrast signal between fingerprint ridges, and further to form a clear fingerprint image.

In contrast to fig. 4, fig. 5 shows a schematic view of the vertical direction light when the glass cover plate is touched by a dry finger. As shown in fig. 5, when the dry finger touches the glass cover plate surface, the signal magnitude of the dry finger and wet finger valley areas are substantially the same; but since the contact of the fingerprint ridge line of the dry finger with the surface is not good for wetting the finger, an air film is formed on the ridge area and the surface of the dry finger; the light signal absorbed by the skin at the position of the ridge corresponding to the contact surface of the cover plate is reduced, and the reflection component is increased; the signal at the ridges of a dry finger will be stronger than a wet finger; the line definition degree is in direct proportion to the difference value of the valley line signal minus the ridge line signal; the ridge line signal of the dry finger rises, and the valley-ridge difference is reduced, so that the lines are blurred compared with wet fingers.

The dry finger has an increased air layer when in contact with the surface of the glass cover plate relative to the wet finger, resulting in less light energy being absorbed by the skin and an increased amount of reflection being felt by the sensor, so that the reflected light intensity is greater for the dry finger relative to the wet finger.

Optionally, in this embodiment of the present application, at least one feature value of the first fingerprint image may be extracted according to the first fingerprint image, and the current dry humidity value may be determined based on the at least one feature value. The at least one characteristic value may include, for example, a value for characterizing the sharpness of a fingerprint image, a reflected light intensity value, a valley and ridge signal amount, and the like.

Specifically, the amplitude of the gradient can reflect the contrast of tiny details in an image and the change of image textures finely, the image has a clearer edge when the image quality is good, the gradient value is not zero, and the corresponding image point and the neighborhood have gray level change and an edge exists; the larger the gradient value is, the sharper the edge of the corresponding point is, and the better the contrast of the image is. Therefore, in the embodiment of the present application, the value for characterizing the sharpness of the fingerprint image may be a gradient value of the fingerprint image, but the embodiment of the present application should not be limited thereto.

Optionally, in this embodiment of the application, obtaining the gradient value of the first fingerprint image may be performing a gradient operation on the first fingerprint image, for example, performing a gradient operation in a horizontal direction and/or a vertical direction on the first fingerprint image to obtain the gradient value of the first fingerprint image, or further performing another operation on the gradient value in the horizontal direction and the gradient value in the vertical direction to obtain the gradient value of the first fingerprint image. For example, assuming that the gradient value in the horizontal direction is C and the gradient value in the vertical direction is D, the gradient values can be calculated

Is determined as a gradient value of the first fingerprint image. For another example, assuming that the gradient value in the horizontal direction is C and the gradient value in the vertical direction is D, the calculation result of (C + D)/2 may be determined as the gradient value of the first fingerprint image.

Optionally, before performing the gradient operation on the first fingerprint image, the first fingerprint image may be filtered, for example, low-pass filtering (LPF) may be performed to filter out the high-frequency noise.

That is, in the embodiment of the present application, the current dry-wet value may be determined in combination with the gradient value of the first fingerprint image and/or the reflected light intensity value of the first fingerprint image.

For example, a gradient value of the first fingerprint image may be determined as a current dry-wet value; or the reflected light intensity value of the first fingerprint image may be determined as the current dryness-humidity value. Alternatively, the current dry-wet value may be determined by performing various operations on the gradient value of the first fingerprint image and the reflected light intensity value of the first fingerprint image.

For example, the gradient values of the first fingerprint image and the reflected light intensity values of the first fingerprint image may be weighted. Assuming that the gradient value of the first fingerprint image is a, the reflected light intensity value of the first fingerprint image is B, the weight of the gradient value of the first fingerprint image is w1, and the weight of the reflected light intensity value of the first fingerprint image is w2, the calculation result of (w1 a + w 2B) may be determined as the current dry-wet value. Wherein w1 and w2 are both not 0 and w1+ w2 is 1.

Alternatively, w1 may be greater than w 2. Since the gradient values are more indicative of finger dryness than the reflected light intensity values, the gradient values are weighted more heavily than the reflected light intensity values. For example, w1 may be 0.6, w2 may be 0.4; or w1 may be 0.7, w2 may be 0.3, etc.

In another alternative embodiment, the gradient value of the first fingerprint image and the average of the reflected light intensity values of the first fingerprint image may be determined as the current dry-wet value.

It should be noted that, although the gradient value and the reflected light intensity value are taken as examples to determine the dry humidity value, it should not be excluded that other possible characteristic values are obtained by the above method.

Optionally, in this embodiment of the present application, the dryness fraction of the finger may be determined according to a relationship between the current dryness fraction and at least one threshold, wherein the at least one threshold may be determined according to a historical dryness fraction.

The dryness fraction may be divided by a threshold. For example, one threshold corresponds to two levels of dryness and humidity, two thresholds correspond to three levels of dryness and humidity, and so on.

After the current dryness and humidity value is obtained, the current dryness and humidity value may be compared with at least one threshold, so that a dryness and humidity level corresponding to the current dryness and humidity value may be determined.

Optionally, in this embodiment, the at least one threshold may be determined according to a historical dryness fraction value. Optionally, the at least one threshold value may be determined already before the current value of the dryness fraction is obtained. For example, the at least one threshold may be updated periodically, and the current psychrometric value may be compared to the at least one threshold that was updated most recently. Optionally, after the current value of the humidity and humidity is obtained, the at least one threshold may also be determined according to a value of the humidity and humidity within a past period of time including the current value of the humidity and humidity, and further, the current value of the humidity and humidity may be compared with the determined at least one threshold, or the determined at least one threshold is used for comparing with a next obtained current value of the humidity and humidity, which is not limited in this embodiment of the application.

Optionally, in this embodiment of the application, a dryness and humidity histogram may be obtained according to a dryness and humidity value corresponding to a plurality of historical fingerprint images; and determining the at least one threshold value according to the dryness-humidity histogram.

The psychrometric histogram may include a plurality of histograms, which may be used to represent the psychrometric value versus the number of fingerprint images. As shown in fig. 6, the abscissa of the psychrometric histogram represents the psychrometric value, and the ordinate of the psychrometric histogram represents the number of fingerprint images (which may also be referred to as the number of samples, and in the embodiment of the present application, one fingerprint image represents one sample).

Specifically, a plurality of histograms may be drawn from the left side to the right side of the psychrometric histogram according to the psychrometric values corresponding to the historical fingerprint image, taking 10 histograms in fig. 6 as an example, specifically, the number of samples with psychrometric values at 1,2, … …, and 10 may be counted respectively by dividing the maximum psychrometric value and the minimum psychrometric value in the psychrometric values corresponding to the historical fingerprint image into 10 equal parts, for example, the maximum psychrometric value is 10, and the minimum psychrometric value is 0 (it should be understood that the actual psychrometric value may be between the psychrometric values between every two histograms, and the number of samples of which histogram may be counted according to which psychrometric value is closest).

After the dryness and humidity histogram is obtained, the dryness and humidity histogram may be traversed from left to right, and the dryness and humidity value at the first inflection point is determined as the first threshold, where the number of fingerprint images represented by the histogram on the left side of the first inflection point is in a decreasing trend, and the number of fingerprint images represented by the histogram on the right side of the first inflection point is in an increasing trend.

For example, as can be seen in fig. 6, if the value of the dry-to-wet at the first inflection point is 4, then the first threshold value may be 4.

For another example, the value of the psychrometric degree at the histogram after the first inflection point may be determined as the first threshold. Or the dryness fraction value at a histogram centered in the dryness fraction histogram may also be determined as the first threshold, and the embodiment of the present application is not limited to how to determine the threshold from the dryness fraction histogram.

It should be understood that several thresholds are specifically derived from the psychrometric histogram as determined by how finely the psychrometric level is divided. If the dryness and humidity levels are only roughly divided into a dry finger level and a wet finger level, only one threshold value needs to be obtained from the dryness and humidity histogram.

For example, a first threshold value is obtained from the dryness-humidity histogram, and if the current dryness-humidity value is less than or equal to the first threshold value, the dryness-humidity level of the finger is a dry finger level; if the current dry-to-wet value is greater than the first threshold, then the dry-to-wet level of the finger is a wet-to-finger level.

Since the at least one threshold is obtained from the psychrometric histogram, the update interval of the psychrometric histogram may be the same as the update interval of the at least one threshold.

Optionally, in this embodiment, after determining the dryness/humidity level according to the current dryness/humidity value, the processor may add the dryness/humidity level to a stored dryness/humidity level list, where the dryness/humidity level list stores a plurality of dryness/humidity levels in a past period of time, and the user may see the skin condition of the user in the past period of time through the dryness/humidity level list. For example, a dry humidity level over the past month. Assuming that the dry humidity level is divided into a dry finger level and a wet finger level, 50 dry humidity levels were recorded in the past month, wherein 40 dry finger levels and 10 wet finger levels, the user can know that his skin is in a dry state and needs to be replenished with water in the past period of time.

Optionally, after the processor determines the dryness and humidity level according to the current dryness and humidity value, the processor may control the display screen to display the dryness and humidity level, so that the user knows the dryness and humidity degree of the skin of the user in real time, and timely water supplement is facilitated.

Further, the processor may also determine a dryness fraction score of the finger according to a dryness fraction corresponding to the dryness fraction level. That is, all of the psychrometric levels may be divided into a plurality of psychrometric intervals, each psychrometric interval corresponding to a psychrometric score.

For the skin, although the wet state is better than the dry state, it does not mean that the wetter the better. Thus, a dryness fraction indicating the most humid may correspond to a non-highest dryness fraction. For example, the humidity level may be 8 levels from dry to wet, and the 8 levels may correspond to 4 humidity intervals, i.e., level 1-2 corresponds to interval 1, level 3-4 corresponds to interval 2, level 5-6 corresponds to interval 3, and level 7-8 corresponds to interval 4. The interval 1 may be an extremely dry interval, the interval 2 may be a dry interval, the interval 3 may be a wet interval, and the interval 4 may be an extremely wet interval. Corresponding scores may be 30%, 60%, 90%, 75%, respectively.

Similarly, after the dryness fraction of the finger is obtained, the dryness fraction can be added to a dryness fraction report, the dryness fraction report stores a plurality of dryness fractions in a past period, and a user can see the skin state of the user in the past period through the dryness fraction report. Fig. 7 and 8 show a recent-phase psychrometric report and a monthly psychrometric report over the past year, respectively. Wherein, in fig. 7, the psychrometric score for each week may be the mean of a plurality of psychrometric scores over a week. Likewise, in fig. 8, the dryness fraction per month may be the mean of a plurality of dryness fractions over a month.

A specific implementation of the solution of the present application will be described below with reference to fig. 9.

As shown in fig. 9, after the user unlocks, the original data 1 obtained from the sensor may be cached, and the original data 1 may be operated in two ways. First, the reference data (base) is subtracted from the original data 1, and the reference data may include a light leakage component of the display screen and data when the sensor is not sensitive to light; further obtaining fingerprint data formed by finger reflection, and obtaining a reflected light intensity value according to the fingerprint data, and recording the reflected light intensity value as B1; firstly, performing LPF on the original data 1, filtering high-frequency noise, and recording the filtered image as an image 1; the image 1 is further subjected to gradient calculation in the horizontal direction and the vertical direction to obtain a gradient value, which is denoted as a 1. And performing weighting operation on the reflected light intensity value B1 and the gradient value A1 obtained by the two operations, namely calculating the values of w 1A 1+ w 2B 1 to obtain the dry humidity value corresponding to the original data 1. Similarly, the humidity value corresponding to the original data 2 can be obtained from w1 a2+ w 2B 2, … …, and the humidity value corresponding to the original data n can be obtained from w1 An + w2 Bn.

After obtaining the humidity values corresponding to a plurality of historical raw data (e.g., raw data 2 to raw data n), a humidity histogram may be obtained. Through traversing the dryness and humidity histogram, the dryness and humidity value at the first inflection point in the dryness and humidity histogram (the number of fingerprint images represented by the histogram on the left side of the first inflection point is in a decreasing trend, and the number of fingerprint images represented by the histogram on the right side of the first inflection point is in an increasing trend) can be used as a threshold value to be compared with the dryness and humidity value corresponding to the current original data (original data 1), so that the dryness and humidity level corresponding to the original data 1 can be obtained. Further, a humidity score corresponding to the original data 1 can be obtained according to a humidity interval where a humidity level corresponding to the original data 1 is located, and a humidity score corresponding to the original data 2, … … and a humidity score corresponding to the original data n can be obtained through a similar method, and a humidity report is formed.

The technical scheme of the embodiment of the application can be used for the technology of fingerprint identification under the screen. Fingerprint identification technique is indicating to install the optical fingerprint module in the display screen below under the screen to realize carrying out the fingerprint identification operation in the display area of display screen, need not set up the fingerprint collection region in the positive region except that the display area of electronic equipment. Specifically, the optical fingerprint module uses light returning from the top surface of the display assembly of the electronic device to perform fingerprint sensing and other sensing operations. This returned light carries information about an object (e.g., a finger) in contact with the top surface of the display assembly, and the optical fingerprint module located below the display assembly performs underscreen fingerprint identification by capturing and detecting this returned light. Among other things, the design of the optical fingerprint module may be such that the desired optical imaging is achieved by appropriately configuring the optical elements used to collect and detect the returned light.

In this application embodiment, the fingerprint image that the optics fingerprint module was acquireed not only can be used for carrying out fingerprint identification, can also be used for acquireing the humidity value that corresponds, and then can confirm the humidity level of finger.

Therefore, according to the technical scheme for detecting the finger dryness and humidity, the unlocking data of the user can be utilized, the data acquisition is simple and convenient, the assistance of other equipment is not needed, the information acquisition and recording are not needed, more operations of the user are not needed, and the generated dryness and humidity report is accurate due to the fact that the unlocking data is bound with the finger of the user and no interference of other data exists.

Optionally, an embodiment of the present application further provides an electronic device, including the device for detecting finger dryness and humidity in the above various embodiments.

Alternatively, the electronic device according to the embodiment of the present application may be a portable or mobile computing device such as a smart phone, a notebook computer, a tablet computer, a game device, and other electronic devices such as an electronic database, an automobile, and an Automated Teller Machine (ATM). The embodiments of the present application do not limit this.

Optionally, the electronic device of the embodiment of the present application may further include a display screen.

Fig. 10A and 10B are schematic diagrams illustrating an electronic device 200 to which an off-screen fingerprint identification technology can be applied, where fig. 10A is a schematic diagram of a front side of the electronic device 200, and fig. 10B is a schematic diagram of a partial cross-sectional structure of the electronic device 200 shown in fig. 10A along a-a'.

As shown in fig. 10A and 10B, the electronic device 200 may include a display screen 220 and an optical fingerprinting device 240. The optical fingerprint device 240 may be the optical fingerprint module 110 described in the above embodiments.

The display screen 220 may be a self-luminous display screen employing display units having self-luminous properties as display pixels. For example, the display screen 220 may be an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. In other alternative embodiments, the Display 220 may also be a Liquid Crystal Display (LCD) or other passive light emitting Display, which is not limited in this embodiment of the present application.

In addition, the display screen 220 may be a touch display screen, which not only can display images, but also can detect a touch or pressing operation of a user, thereby providing a human-computer interaction interface for the user. For example, in one embodiment, the electronic device 200 may include a Touch sensor, which may be embodied as a Touch Panel (TP), and may be disposed on a surface of the display screen 220, or may be partially or wholly integrated within the display screen 220, so as to form the Touch display screen.

In particular, the optical fingerprint device 240 may include a fingerprint sensor chip (hereinafter also referred to as an optical fingerprint sensor or optical fingerprint chip) having an optically sensitive array. The optical sensing array includes a plurality of optical sensing units, and each optical sensing unit may specifically include a photodetector or a photosensor. Alternatively, the optical fingerprint device 240 may include a Photo detector array (or referred to as a Photo detector array, a Photo sensor array, an optical sensor array, or a sensing array), which includes a plurality of Photo detectors distributed in an array.

As shown in fig. 10A, the optical fingerprinting device 240 may be arranged in a partial area below the display screen 220 such that the fingerprint acquisition area (or fingerprint detection area) 230 of the optical fingerprinting device 240 is at least partially located within the display area 202 of the display screen 220.

Of course, in other alternative embodiments, the optical fingerprint device 240 may be disposed in other locations, such as the side of the display 220 or the edge non-transparent area of the electronic device 200. In this case, the optical signal of at least a portion of the display area of the display screen 220 may be guided to the optical fingerprint device 240 by the optical path design, so that the fingerprint acquisition area 230 is actually located within the display area of the display screen 220.

In some embodiments of the present application, the optical fingerprint device 240 may include only one fingerprint sensor chip, and the area of the fingerprint collection area 230 of the optical fingerprint device 240 is small and the location is fixed, so that a user needs to press a finger to a specific location of the fingerprint collection area 230 when performing a fingerprint input, otherwise the optical fingerprint device 240 may not collect a fingerprint image and the user experience is poor.

In other embodiments of the present application, the optical fingerprint device 240 may specifically include a plurality of fingerprint sensor chips; the plurality of fingerprint sensor chips may be disposed side by side in a splicing manner below the display screen 220, and sensing areas of the plurality of fingerprint sensor chips jointly constitute a fingerprint collecting area 230 of the optical fingerprint device 240. That is to say, the fingerprint collection area 230 of the optical fingerprint device 240 may include a plurality of sub-areas, each of which corresponds to the sensing area of one of the fingerprint sensor chips, so that the fingerprint collection area 230 of the optical fingerprint module 230 may be extended to the main area of the lower half portion of the display screen, i.e., to the area that the finger presses conventionally, thereby implementing the blind-touch fingerprint input operation. Alternatively, when the number of fingerprint sensor chips is sufficient, the fingerprint detection area 230 may also be extended to half or even the entire display area, thereby enabling half-screen or full-screen fingerprint detection.

It should be understood that the specific form of the fingerprint sensor chips is not limited in the embodiments of the present application. For example, the plurality of fingerprint sensor chips may be individually packaged fingerprint sensor chips, or may be a plurality of chips (Die) packaged in the same chip package. Also for example, the plurality of fingerprint sensor chips may be fabricated on different regions of the same chip (Die) by a semiconductor process.

As shown in fig. 10B, the optical sensing array of the optical fingerprint device 240 is located in an area or a light sensing range corresponding to the fingerprint capturing area 230 of the optical fingerprint device 240. The fingerprint collecting area 230 of the optical fingerprint device 240 may be equal to or not equal to the area or the light sensing range of the area where the optical sensing array of the optical fingerprint device 240 is located, which is not specifically limited in this embodiment of the application.

For example, by designing the light path of the light rays to be collimated, the fingerprint acquisition area 230 of the optical fingerprint device 240 may be designed to substantially coincide with the area of the sensing array of the optical fingerprint device 240.

For another example, the area of the fingerprint collection area 230 of the optical fingerprint device 240 may be larger than the area of the sensing array of the optical fingerprint device 240 by the optical path design of the converging light or the optical path design of the reflecting light.

In some embodiments of the present disclosure, the optical fingerprint device 240 may further include an optical component, which may be disposed above the sensor array, and may specifically include a Filter layer (Filter), a light guide layer or a light path guiding structure, and other optical elements, where the Filter layer may be used to Filter out ambient light penetrating through the finger, for example, infrared light interfering with imaging, and the light guide layer or the light path guiding structure is mainly used to guide reflected light reflected from the surface of the finger to the sensor array for optical detection.

The optical path design of the optical fingerprint device 240 is illustratively described below.

As an embodiment, the optical fingerprint device 240 may employ an optical Collimator with a through hole array having a high aspect ratio, where the optical Collimator may specifically be a Collimator (Collimator) layer made of a semiconductor silicon wafer, and the Collimator layer has a plurality of collimating units or micro-holes, the collimating units may specifically be micro-holes, and in reflected light reflected from a finger, light perpendicularly incident to the collimating units may pass through and be received by a fingerprint sensor chip below the collimating units, and light with an excessively large incident angle is attenuated by multiple reflections inside the collimating units, so that each fingerprint sensor chip can basically only receive reflected light reflected by fingerprint lines directly above the fingerprint sensor chip, and image resolution can be effectively improved, and fingerprint identification effect is improved.

Further, when the optical fingerprint device 240 includes a plurality of fingerprint sensor chips, a collimating unit may be configured for one optical sensing unit in the optical sensing array of each fingerprint sensor chip, and the collimating unit is disposed above the corresponding optical sensing unit. Of course, the plurality of optical sensing units may also share one collimating unit, i.e. the one collimating unit has a sufficiently large aperture to cover the plurality of optical sensing units. Because a collimating unit can correspond to a plurality of optical sensing units, the correspondence between the spatial period of the display screen 220 and the spatial period of the fingerprint sensor chip is destroyed, so that even if the spatial structure of the light-emitting display array of the display screen 220 is similar to the spatial structure of the optical sensing array of the fingerprint sensor chip, the optical fingerprint device 240 can be effectively prevented from generating moire fringes by utilizing the optical signal passing through the display screen 220 to perform fingerprint imaging, and the fingerprint identification effect of the optical fingerprint device 240 is effectively improved.

As another example, the optical fingerprint device 240 may adopt an optical path design based on an optical Lens, and the optical Lens may include an optical Lens (Lens) layer having one or more Lens units, such as a Lens group consisting of one or more aspheric lenses, for converging the reflected light reflected from the finger to a sensing array of the fingerprint sensor chip therebelow, so that the sensing array may image based on the reflected light, thereby obtaining the fingerprint image of the finger. The optical lens layer may further form a pinhole in an optical path of the lens unit, and the pinhole may cooperate with the optical lens layer to enlarge a field of view of the optical fingerprint device 240, so as to improve a fingerprint imaging effect of the optical fingerprint device 240.

Further, when the optical fingerprint device 240 includes a plurality of fingerprint sensor chips, an optical lens may be configured for each fingerprint sensor chip to perform fingerprint imaging, or an optical lens may be configured for a plurality of fingerprint sensor chips to implement light convergence and fingerprint imaging. Even when one fingerprint sensor chip has two sensing arrays (Dual Array) or multiple sensing arrays (Multi-Array), two or more optical lenses can be configured for the fingerprint sensor chip to cooperate with the two sensing arrays or the multiple sensing arrays to perform optical imaging, so as to reduce the imaging distance and enhance the imaging effect.

As still another example, the optical fingerprint device 240 may employ an optical path design of a Micro-Lens (Micro-Lens) layer, the Micro-Lens layer may have a Micro-Lens array formed by a plurality of Micro-lenses, which may be formed above the sensing array of the fingerprint sensor chip through a semiconductor growth process or other processes, and each Micro-Lens may correspond to one of the sensing units of the sensing array. Other optical film layers such as a dielectric layer or a passivation layer may be further formed between the microlens layer and the sensing units, and more particularly, a light blocking layer having micro holes may be further included between the microlens layer and the sensing units, wherein the micro holes are formed between the corresponding microlenses and the sensing units, and the light blocking layer may block optical interference between adjacent microlenses and the sensing units, and allow light to be converged into the micro holes through the microlenses and transmitted to the sensing units corresponding to the microlenses through the micro holes, so as to perform optical fingerprint imaging.

It should be understood that several implementations of the above-mentioned optical path guiding structure may be used alone or in combination, for example, a microlens layer may be further disposed below the collimator layer or the optical lens layer. Of course, when the collimator layer or the optical lens layer is used in combination with the microlens layer, the specific lamination structure or optical path thereof may need to be adjusted according to actual needs.

The optical fingerprint device 240 may be used to collect fingerprint information (e.g., fingerprint image information) of a user.

As an alternative embodiment, the display screen 220 may adopt a display screen having a self-luminous display unit, such as an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. Taking the OLED display screen as an example, the optical fingerprint device 240 may utilize the display unit (i.e., the OLED light source) of the OLED display screen located in the fingerprint acquisition area 230 as an excitation light source for optical fingerprint detection.

When a finger touches, presses, or approaches (collectively referred to as pressing in this application for convenience of description) the fingerprint collection area 230, the display 220 emits a beam of light to the finger above the fingerprint collection area 230, and the beam of light is reflected on the surface of the finger to form reflected light or scattered light after being scattered by the inside of the finger, and the reflected light and the scattered light are collectively referred to as reflected light in the related patent application for convenience of description. Because ridges (ridges) and valleys (vally) of the fingerprint have different light reflection capabilities, reflected light from the ridges and the valleys of the fingerprint have different light intensities, and the reflected light is received by the fingerprint sensor chip in the optical fingerprint device 240 and converted into corresponding electric signals, i.e., fingerprint detection signals, after passing through the display screen 220; fingerprint image data can be obtained based on the fingerprint detection signal, and fingerprint matching verification can be further performed, so that an optical fingerprint identification function is realized in the electronic device 200.

Therefore, when the user needs to perform fingerprint unlocking or other fingerprint verification on the electronic device 200, the user only needs to press a finger on the fingerprint acquisition area 230 of the display screen 220, so that the input operation of the fingerprint characteristics can be realized. Because the collection of the fingerprint features can be implemented inside the display area 202 of the display screen 220, the electronic device 200 adopting the above structure does not need a special reserved space on the front surface thereof to set the fingerprint keys (such as the Home key), and thus a full screen scheme can be adopted. Thus, the display area 202 of the display screen 220 may extend substantially across the entire front face of the electronic device 200.

In other alternative embodiments, the optical fingerprint device 240 may also use an internal light source or an external light source to provide an optical signal for fingerprint detection and identification. In this case, the optical fingerprint device 240 may be applied not only to a self-luminous display such as an OLED display but also to a non-self-luminous display such as a liquid crystal display or other passive luminous display.

Taking an application to a liquid crystal display screen having a backlight module and a liquid crystal panel as an example, to support the underscreen fingerprint detection of the liquid crystal display screen, the optical fingerprint system of the electronic device 200 may further include an excitation light source for optical fingerprint detection, where the excitation light source may specifically be an infrared light source or a light source of non-visible light with a specific wavelength, and may be disposed below the backlight module of the liquid crystal display screen or in an edge area below a protective cover plate of the electronic device 200, and the optical fingerprint device 240 may be disposed below the edge area of the liquid crystal panel or the protective cover plate and guided through a light path so that the fingerprint detection light may reach the optical fingerprint device 240; alternatively, the optical fingerprint device 240 may be disposed below the backlight module, and the backlight module may be perforated or otherwise optically designed to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint device 240. When the optical fingerprint device 240 is used to provide an optical signal for fingerprint detection by using an internal light source or an external light source, the detection principle may be the same.

As shown in fig. 10A, the electronic device 200 may further include a transparent protective cover 210, such as a glass cover or a sapphire cover, which is located above the display 220 and covers the front surface of the electronic device 200, and the surface of the cover 210 may be further provided with a protective layer. Therefore, in the embodiment of the present application, the pressing of the display screen 220 by the finger may actually mean that the finger presses the cover 210 above the display screen 220 or a surface of a protective layer covering the cover 210.

As shown in fig. 10B, a Circuit board 250, such as a Flexible Printed Circuit (FPC), may be further disposed below the optical fingerprint device 240.

In the above, the specific structure of the device for detecting finger dryness and humidity according to the embodiment of the present application is described. The method 300 for detecting finger dryness according to the embodiment of the present application will be described in detail with reference to fig. 11. Specifically, as shown in fig. 11, the method 300 includes:

s310, acquiring a current dry-wet value corresponding to a first fingerprint image according to the first fingerprint image, wherein the first fingerprint image is a fingerprint image obtained by reflected light formed by reflecting light irradiating a finger;

s320, determining the dryness and humidity level of the finger according to the current dryness and humidity value.

Optionally, in this embodiment of the present application, the obtaining, according to the first fingerprint image, a current dryness-humidity value corresponding to the first fingerprint image includes: acquiring a gradient value and/or a reflected light intensity value of the first fingerprint image according to the first fingerprint image; and determining the current dry-wet value according to the gradient value and/or the reflected light intensity value.

Optionally, in this embodiment of the present application, the determining the current dry-wet value according to the gradient value and the reflected light intensity value includes: determining a calculation result of (w1 a + w 2B) as the current dry-wet value, wherein a is the gradient value, B is the reflected light intensity value, w1 is the weight of the gradient value, w2 is the weight of the reflected light intensity value, w1+ w2 is 1 and neither w1 nor w2 is 0.

Optionally, in embodiments of the present application, w1 is greater than w 2.

Optionally, in this embodiment of the present application, the determining the dryness and humidity level of the finger according to the current dryness and humidity value includes: determining a dryness-humidity level of the finger based on a relationship between the current dryness-humidity value and at least one threshold, the at least one threshold being determined based on historical dryness-humidity values.

Optionally, in an embodiment of the present application, the method further includes: acquiring a dryness-humidity histogram according to the corresponding dryness-humidity values of a plurality of historical fingerprint images, wherein the dryness-humidity histogram comprises a plurality of histograms which are used for representing the corresponding relation between the dryness-humidity values and the number of the fingerprint images; the at least one threshold is determined based on the psychrometric histogram.

Optionally, in an embodiment of the present application, the at least one threshold includes a first threshold, and the determining the at least one threshold according to the dryness fraction histogram includes: and traversing the dryness fraction histogram from left to right, and determining the dryness fraction value at the first turning point as the first threshold, wherein the number of the fingerprint images represented by the histogram on the left side of the first turning point is in a decreasing trend, and the number of the fingerprint images represented by the histogram on the right side of the first turning point is in an increasing trend.

Optionally, in this embodiment of the present application, the determining the dryness fraction of the finger according to the relationship between the current dryness fraction and at least one threshold value includes: if the current dryness-humidity value is less than or equal to the first threshold, determining the dryness-humidity level of the finger as a dry finger level; or if the current dry-wet value is greater than the first threshold, determining that the dry-wet level of the finger is a wet-finger level.

Optionally, in an embodiment of the present application, the method further includes: and determining the dryness fraction of the finger according to the dryness fraction corresponding to the current dryness fraction.

Optionally, in an embodiment of the present application, the method further includes: adding the finger's dryness fraction to a dryness fraction report, the dryness fraction report including a plurality of historical dryness fractions.

Optionally, in this embodiment of the application, the obtaining, according to the first fingerprint image, a gradient value corresponding to the first fingerprint image includes: performing gradient operation in the horizontal direction and the vertical direction on the first fingerprint image after low-pass filtering; and averaging the gradient amplitude in the horizontal direction and the gradient amplitude in the vertical direction to obtain the gradient value.

It should be noted that the method 300 for detecting finger dryness according to the embodiment of the present application can be implemented by the apparatus 100 for detecting finger dryness according to the embodiment of the present application, and specific implementation refers to the related description of the foregoing embodiment, and is not repeated herein.

It should be understood that the processor of the embodiments of the present application may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The Processor may be a general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, or discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A device for detecting finger dryness, the device comprising:

the optical fingerprint module is used for receiving reflected light formed by reflecting the light irradiation finger so as to obtain a first fingerprint image, and the first fingerprint image is used for obtaining the current humidity value corresponding to the first fingerprint image so as to determine the humidity level of the finger.

2. The apparatus of claim 1, further comprising:

and the processor is used for acquiring the current dryness and humidity value according to the first fingerprint image and determining the dryness and humidity level of the finger according to the current dryness and humidity value.

3. The apparatus of claim 2, wherein the processor obtains the current value of dry-wet from the first fingerprint image, comprising:

acquiring a gradient value and/or a reflected light intensity value of the first fingerprint image according to the first fingerprint image;

and determining the current dry-wet value according to the gradient value and/or the reflected light intensity value.

4. The apparatus of claim 3, wherein the processor determines the current dry-to-wet value from the gradient values and the reflected light intensity values, comprising:

determining a calculation result of (w1 a + w 2B) as the current dry-wet value, wherein a is the gradient value, B is the reflected light intensity value, w1 is a weight of the gradient value, w2 is a weight of the reflected light intensity value, w1+ w2 is 1, and neither w1 nor w2 is 0.

5. The device of claim 4, wherein w1 is greater than w 2.

6. The apparatus of any one of claims 2 to 5, wherein the processor determines the finger dryness fraction from the current dryness fraction value, comprising:

determining a dryness-humidity level of the finger according to a relationship between the current dryness-humidity value and at least one threshold, the at least one threshold being determined according to historical dryness-humidity values.

7. The apparatus of claim 6, wherein the processor is further configured to:

acquiring a dryness-humidity histogram according to the corresponding dryness-humidity values of a plurality of historical fingerprint images, wherein the dryness-humidity histogram comprises a plurality of histograms which are used for representing the corresponding relation between the dryness-humidity values and the number of the fingerprint images;

determining the at least one threshold value from the psychrometric histogram.

8. The apparatus of claim 7, wherein the at least one threshold comprises a first threshold, and wherein the processor determines the at least one threshold from the psychrometric histogram comprises:

and traversing the dryness-humidity histogram from left to right, and determining the dryness-humidity value at a first inflection point as the first threshold, wherein the number of the fingerprint images represented by the histogram on the left side of the first inflection point is in a decreasing trend, and the number of the fingerprint images represented by the histogram on the right side of the first inflection point is in an increasing trend.

9. The apparatus of claim 8, wherein the processor determines the finger dryness fraction from the current dryness fraction in relation to at least one threshold, comprising:

if the current dryness-humidity value is smaller than or equal to the first threshold, determining that the dryness-humidity level of the finger is a dry finger level; or

And if the current dry humidity value is larger than the first threshold value, determining that the dry humidity level of the finger is a wet finger level.

10. The apparatus of any of claims 2 to 9, wherein the processor is further configured to:

and determining the dryness-humidity score of the finger according to the dryness-humidity interval corresponding to the dryness-humidity level of the finger.

11. The apparatus of claim 10, wherein the processor is further configured to:

and storing the finger dryness and humidity scores into a dryness and humidity report, wherein the dryness and humidity report comprises a plurality of historical dryness and humidity scores.

12. The apparatus according to any one of claims 3 to 5, wherein the processor obtains gradient values of the first fingerprint image from the first fingerprint image, including:

and performing gradient operation in the horizontal direction and the vertical direction on the first fingerprint image after low-pass filtering to obtain the gradient value.

13. A method of detecting finger dryness, comprising:

acquiring a current dry-wet value corresponding to a first fingerprint image according to the first fingerprint image, wherein the first fingerprint image is a fingerprint image obtained by reflected light formed by reflecting light irradiating a finger;

and determining the dryness-humidity level of the finger according to the current dryness-humidity value.

14. The method of claim 13, wherein the obtaining, from the first fingerprint image, a current value of the dryness fraction corresponding to the first fingerprint image comprises:

15. The method of claim 14, wherein determining the current dry-wet value from the gradient values and the reflected light intensity values comprises:

16. The method of claim 15, wherein w1 is greater than w 2.

17. The method of any one of claims 13 to 16, wherein said determining a dryness fraction of the finger based on the current dryness fraction value comprises:

18. The method of claim 17, further comprising:

determining the at least one threshold value from the psychrometric histogram.

19. The method of claim 18, wherein the at least one threshold comprises a first threshold, and wherein determining the at least one threshold from the psychrometric histogram comprises:

20. The method of claim 19, wherein said determining a dryness fraction of said finger based on a relationship between said current dryness fraction and at least one threshold value comprises:

21. The method according to any one of claims 13 to 20, further comprising:

and determining the dryness and humidity score of the finger according to the dryness and humidity interval corresponding to the current dryness and humidity level.

22. The method of claim 21, further comprising:

and adding the finger dryness and humidity score into a dryness and humidity report, wherein the dryness and humidity report comprises a plurality of historical dryness and humidity scores.

23. The method according to any one of claims 14 to 16, wherein the obtaining the gradient value corresponding to the first fingerprint image according to the first fingerprint image comprises:

24. An electronic device, characterized in that it comprises an apparatus according to any one of claims 1 to 12.