WO2020154926A1 - Fingerprint detection method, fingerprint detection apparatus, and electronic device - Google Patents

Abstract

Embodiments of the present application provide a fingerprint detection method, a fingerprint detection apparatus, and an electronic device. The fingerprint detection method comprises: when a finger of a user presses a target pattern which is displayed in a fingerprint detection area of a display screen of the electronic device, detecting reflected optical signals, which are formed by reflecting, on the finger of the user, target optical signals corresponding to the target pattern, wherein the target pattern comprises a first pattern and a second pattern, the first pattern is closer to the center of the fingerprint detection area than the second pattern, and the chromatic dispersion degree of a first optical signal corresponding to the first pattern is stronger than the chromatic dispersion intensity of a second optical signal corresponding to the second pattern; and obtaining fingerprint information of the finger of the user according to the reflected optical signals.

Description

Fingerprint detection method, fingerprint detection device and electronic equipment Technical field

This application relates to the field of optical fingerprint technology, and more specifically, to a fingerprint detection method, fingerprint detection device, and electronic equipment.

Background technique

The application of optical fingerprint devices brings users a safe and convenient user experience. However, based on the optical imaging principle of optical components (such as lenses) in optical fingerprint devices, the focal plane of optical fingerprints is usually curved, while optical fingerprint devices The image plane of the sensor is flat, which causes the edge detection area of the fingerprint detection area to be out of focus, that is, the actual focal length of the edge detection area is smaller than the image distance, as shown in Figure 1, which in turn leads to the reduction of the effective fingerprint detection area. Affect fingerprint recognition rate.

Summary of the invention

A fingerprint detection method, fingerprint detection device and electronic equipment are provided, which can improve fingerprint recognition rate.

In the first aspect, a fingerprint detection method is provided, including:

When the user's finger presses the target pattern displayed in the fingerprint detection area of the display screen of the electronic device, the target light signal corresponding to the target pattern is detected as a reflected light signal formed by the reflection of the user's finger, wherein the target pattern includes the first A pattern and a second pattern, the first pattern is closer to the center of the fingerprint detection area than the second pattern, and the dispersion degree of the first optical signal corresponding to the first pattern is greater than that of the second pattern The dispersion intensity of the corresponding second optical signal;

Obtaining fingerprint information of the user's finger according to the reflected light signal.

In some possible implementation manners, the target pattern is a light spot that includes multiple patterns, and the dispersion degree of the optical signal corresponding to the multiple patterns is in order from the closest to the center of the fingerprint detection area. Decreasing.

In some possible implementation manners, the multiple patterns are a blue light spot, a cyan light spot, a green light spot, and a yellow light spot in an order from near to far from the center of the fingerprint detection area.

In some possible implementation manners, the gray values of the three primary colors of red, green, and blue in the optical signals corresponding to the multiple patterns are different.

In some possible implementations, the gray value of blue in the first pattern is greater than the gray value of blue in the second pattern, and the gray value of green in the first pattern is less than the The gray value of green in the second pattern.

In some possible implementation manners, the method further includes:

The gray values of the three primary colors of RGB in the light signals emitted to different areas of the fingerprint detection area are determined to form the target pattern in the fingerprint detection area.

In some possible implementation manners, the determining the gray values of the three primary colors of red, green, and blue in the light signals emitted to different areas of the fingerprint detection area includes:

According to at least one of the following, determine the gray values of the three primary colors of RGB in the light signals emitted to the different areas of the fingerprint detection area: the response coefficient of the optical sensor to the light signals of different colors, and the light signals of different colors at all The actual image distances of different areas of the optical sensor, the modulation transfer function MTF of the optical sensor for the light signals of the three primary colors, and the attenuation coefficient of the brightness of the light signals of different colors with the gray value.

In some possible implementations, the target pattern is formed by a target light signal emitted by a light source in the fingerprint detection area, wherein the light source includes at least one of a red light source, a green light source, and a blue light source; the method further include:

By controlling the gray values of the red, green, and blue RGB primary colors of the first light signal and the second light signal emitted by at least one of the red light source, the green light source, and the blue light source, so that The dispersion degree of the first optical signal is greater than the dispersion intensity of the second optical signal.

In some possible implementation manners, the wavelength of the first optical signal is smaller than the wavelength of the second optical signal.

In some possible implementation manners, the actual focal length of the first optical signal is smaller than the actual focal length of the second optical signal.

In a second aspect, a fingerprint detection device is provided, including an optical component and an optical sensor, the optical component is used to guide or converge fingerprint detection signals to the optical sensor, and the optical sensor is used to detect fingerprints according to the Signal detection corresponding fingerprint information;

Wherein, the fingerprint detection signal is a reflected light signal formed by the reflection of the optical signal corresponding to the target pattern formed in the fingerprint detection area of the display screen on the user's finger, and the target pattern includes a first pattern and a second pattern. The first pattern is closer to the center of the fingerprint detection area than the second pattern, and the dispersion degree of the first optical signal corresponding to the first pattern is greater than the dispersion intensity of the second optical signal corresponding to the second pattern .

In some possible implementation manners, the target pattern is a light spot including a plurality of patterns, and the degree of dispersion of the optical signal corresponding to the plurality of patterns decreases in order from the center of the fingerprint detection area from near to far. .

In some possible implementation manners, the multiple patterns are a blue light spot, a cyan light spot, a green light spot, and a yellow light spot in an order from near to far from the center of the fingerprint detection area.

In some possible implementation manners, the gray values of the three primary colors of red, green, and blue in the optical signals corresponding to the multiple patterns are different.

In some possible implementation manners, the multiple patterns include the first pattern and the second pattern, and the gray value of the blue in the first pattern is greater than the gray value of the blue in the second pattern. Degree value, the gray value of green in the first pattern is smaller than the gray value of green in the second pattern.

In some possible implementation manners, the target pattern is formed by a target light signal emitted by a light source in the fingerprint detection area, wherein the light source includes at least one of a red light source, a green light source, and a blue light source.

In some possible implementations, the fingerprint detection device further includes: a light source driving module for driving the light source to emit the first light signal and the light source in the center detection area and the edge detection area of the fingerprint detection area, respectively The second light signal, so that the first pattern and the second pattern are respectively displayed on the fingerprint detection area of the display screen.

In some possible implementation manners, the light source driving module is specifically configured to control the first light signal and the first light signal emitted by at least one of the red light source, the green light source, and the blue light source. The gray values of the three primary colors of red, green, and blue of the two optical signals are such that the dispersion degree of the first optical signal is greater than the dispersion intensity of the second optical signal.

In some possible implementations, the light source is a partial self-luminous display unit of the display screen in the fingerprint detection area, and the red light source, the green light source, and the blue light source are the display units respectively. The red display unit, green display unit and blue display unit of the screen.

In some possible implementation manners, the light source driving module is a display driving module or a display driver for driving the display screen for screen display.

In some possible implementations, the light source is an external light source, and the external light source is arranged below the display screen.

In some possible implementations, the fingerprint detection device further includes: a processing module, configured to determine the gray values of the three primary colors of RGB in the light signals emitted to different areas of the fingerprint detection area, so that the The detection area forms the target pattern.

In some possible implementation manners, the processing module is specifically configured to determine the gray values of the three primary colors of RGB in the light signals emitted to different areas of the fingerprint detection area according to at least one of the following: The response coefficients of light signals of different colors, the actual image distances of light signals of different colors in different areas of the optical sensor, the modulation transfer function MTF of the light signals of the three primary colors of the optical sensor, the brightness of the light signals of different colors Attenuation coefficient with gray value.

In some possible implementations, the optical component includes one or more lenses, and the refractive index of the first optical signal in the lens is greater than the refractive index of the second optical signal in the lens.

In a third aspect, a chip is provided. The chip includes an input/output interface, at least one processor, at least one memory, and a bus. The at least one memory is used to store instructions, and the at least one processor is used to call Instructions to execute the method in the first aspect or any possible implementation of the first aspect.

In a fourth aspect, an electronic device is provided, including a display screen and a fingerprint detection device arranged below the display screen, wherein the fingerprint detection device is as in the second aspect or any possible implementation of the second aspect Fingerprint detection device.

In a fifth aspect, an electronic device is provided, including the chip as in the third aspect.

In a sixth aspect, a computer-readable medium is provided for storing a computer program, and the computer program includes instructions for executing the foregoing first aspect or any possible implementation of the first aspect.

In a seventh aspect, a computer program product including instructions is provided. When the computer runs the instructions of the computer program product, the computer executes the first aspect or any possible implementation of the first aspect. Fingerprint identification method.

Specifically, the computer program product can be run on the electronic device in the fourth aspect to the fifth aspect.

According to the fingerprint detection device of the embodiment of the present application, when designing the optical signal emitted by the excitation light source to the fingerprint detection area, the dispersion degree of the optical signal corresponding to the spot in the edge detection area can be designed to be smaller than the dispersion of the optical signal corresponding to the central detection area. To the extent, for example, the central detection area is preferably a blue light spot, and then transitions to a green light spot and then to a red light spot in turn from the edge. In this way, the edge area of the focal plane of the optical fingerprint can be brought closer to the image plane, thereby improving the edge detection area The over-defocusing phenomenon increases the fingerprint recognition area and further improves the fingerprint recognition rate.

Description of the drawings

Figure 1 is a schematic diagram of the degree of defocus between the focal plane and the image plane.

Fig. 2A is a directional view of an electronic device according to an embodiment of the present application.

Fig. 2B is a schematic diagram of a partial cross-sectional structure of the electronic device shown in Fig. 2A along A-A'.

Fig. 3 is a schematic diagram of the system structure of a fingerprint detection device according to an embodiment of the present application.

Fig. 4 is a schematic diagram of the system structure of a fingerprint detection device according to another embodiment of the present application.

Fig. 5 is a schematic diagram of a color mixing spot according to an embodiment of the present application.

Fig. 6 is a schematic diagram of a fingerprint image collected based on a pure color spot.

FIG. 7 is a comparison diagram of the defocus degree of the focal plane and the image plane based on the pure color spot and the desired defocus degree.

Figure 8 is a graph of the actual image distance of the three primary colors.

Figure 9 is a graph of the attenuation coefficient of the brightness of the three primary colors with the gray value.

Figure 10 is a graph showing the change of the MTF of the three primary colors with the actual image distance.

Figure 11 is the gray value attenuation coefficient curve of the three primary colors in different regions.

FIG. 12 is a schematic diagram of a mixed color spot obtained based on the attenuation coefficient shown in FIG. 11.

FIG. 13 is a comparison diagram based on the focal plane of a pure color spot and a mixed color spot.

Fig. 14 is a comparison diagram of the degree of defocus before and after correction.

FIG. 15 is a schematic diagram of a fingerprint image collected based on a pure color spot and a mixed color spot.

Figure 16 is a comparison diagram of system tolerances based on the green spot and the mixed color spot.

Fig. 17 is a schematic block diagram of a fingerprint detection device according to still another embodiment of the present application.

Fig. 18 is a schematic flowchart of a fingerprint detection method according to an embodiment of the present application.

Fig. 19 is a schematic block diagram of an electronic device according to an embodiment of the present application.

detailed description

The technical solution in this application will be described below in conjunction with the drawings.

As a common application scenario, the optical fingerprint system provided in the embodiments of this application can be applied to smart phones, tablet computers, and other mobile terminals with display screens or other terminal devices; more specifically, in the above-mentioned terminal devices, fingerprint identification The device may specifically be an optical fingerprint device, which may be arranged in a partial area or an entire area below the display screen, thereby forming an under-display optical fingerprint system.

2A and 2B show schematic diagrams of electronic devices to which the embodiments of the present application can be applied, wherein FIG. 2A is a front schematic view of the electronic device 10, and FIG. 2B is the electronic device 10 shown in FIG. 2A along A'-A' Partial sectional structure diagram.

As shown in FIGS. 2A and 2B, the electronic device 10 includes a display screen 120 and an optical fingerprint device 130, wherein the optical fingerprint device 130 is arranged in a partial area under the display screen 120. The optical fingerprint device 130 includes an optical sensor, and the optical sensor includes a sensing array with a plurality of optical sensing units, and the area where the sensing array is located or the sensing area thereof is the fingerprint detection area 103 of the optical fingerprint device 130. As shown in FIG. 2A, the fingerprint detection area 103 is located in the display area of the display screen 120. In an alternative embodiment, the optical fingerprint device 130 may also be arranged in other positions, such as the side of the display screen 120 or the non-transmissive area at the edge of the electronic device 10, and the optical fingerprint device 130 may be designed to The optical signal of at least part of the display area of the display screen 120 is guided to the optical fingerprint device 130, so that the fingerprint detection area 103 is actually located in the display area of the display screen 120.

It should be understood that the area of the fingerprint detection area 103 may be different from the area of the sensing array of the optical fingerprint device 130, for example, through optical path design such as lens imaging, reflective folding optical path design, or other optical path design such as light convergence or reflection, etc. The area of the fingerprint detection area 103 of the optical fingerprint device 130 can be made larger than the area of the sensing array of the optical fingerprint device 130.

Therefore, when the user needs to unlock the electronic device or perform other fingerprint verification, he only needs to press his finger on the fingerprint detection area 103 located in the display screen 120 to realize fingerprint input. Since fingerprint detection can be implemented in the screen, the electronic device 10 adopting the above structure does not need to reserve space on the front side to set fingerprint buttons (such as the Home button), so that a full screen solution can be adopted, that is, the display area of the display screen 120 It can be basically extended to the front of the entire electronic device 10.

As an optional implementation, as shown in FIG. 2A, the optical fingerprint device 130 includes a light detecting part 134 and an optical component 132, and the light detecting part 134 includes the sensor array and is electrically connected to the sensor array. The connected reading circuit and other auxiliary circuits can be fabricated on a chip (Die) by a semiconductor process, such as an optical imaging chip or an optical sensor. The sensing array is specifically a photodetector (Photodetector) array, which includes multiple A photodetector distributed in an array, the photodetector can be used as the optical sensing unit as described above; the optical component 132 can be arranged above the sensing array of the photodetecting part 134, which can specifically include a filter A light layer (Filter), a light guide layer or a light path guiding structure and other optical elements, the filter layer can be used to filter out ambient light penetrating the finger, and the light guide layer or light path guide structure is mainly used to remove light from the finger The reflected light reflected from the surface is guided to the sensing array for optical inspection.

In terms of specific implementation, the optical assembly 132 and the light detecting part 134 may be packaged in the same optical fingerprint component. For example, the optical component 132 and the optical detection part 134 can be packaged in the same optical fingerprint chip, or the optical component 132 can be arranged outside the chip where the optical detection part 134 is located, for example, the optical component 132 is attached above the chip, or some components of the optical assembly 132 are integrated into the chip.

Wherein, the light guide layer or light path guiding structure of the optical component 132 has multiple implementation solutions. For example, the light guide layer or light path guiding structure may be an optical lens (Lens) layer, which has one or more lens units, For example, a lens group composed of one or more aspheric lenses, which is used to converge the reflected light reflected from the finger to the sensing array of the light detection portion 134 below it, so that the sensing array can perform based on the reflected light. Imaging to obtain a fingerprint image of the finger. Optionally, the optical lens layer may further have a pinhole formed in the optical path of the lens unit, and the pinhole may cooperate with the optical lens layer to expand the field of view of the optical fingerprint device to improve the optical The fingerprint imaging effect of the fingerprint device 130.

In other embodiments, the light guide layer or the light path guide structure may also specifically adopt a micro-lens (Micro-Lens) layer. The micro-lens layer has a micro-lens array formed by a plurality of micro-lenses, which can be grown by semiconductors. A process or other processes are formed above the sensing array of the light detecting part 134, and each microlens may correspond to one of the sensing units of the sensing array. In addition, other optical film layers may be formed between the micro lens layer and the sensing unit, such as a dielectric layer or a passivation layer. More specifically, the micro lens layer and the sensing unit may also include The light-blocking layer of the micro-hole, wherein the micro-hole is formed between its corresponding micro-lens and the sensing unit, the light-blocking layer can block the optical interference between the adjacent micro-lens and the sensing unit, and make the sensing The light corresponding to the unit is condensed into the microhole through the microlens and is transmitted to the sensing unit through the microhole to perform optical fingerprint imaging.

As an optional embodiment, the display screen 120 may be a display screen with a self-luminous display unit, such as an organic light-emitting diode (Organic Light-Emitting Diode, OLED) display or a micro-LED (Micro-LED) display Screen. Taking an OLED display screen as an example, the optical fingerprint device 130 may use the display unit (ie, an OLED light source) of the OLED display screen 120 located in the fingerprint detection area 103 as an excitation light source for optical fingerprint detection. When a finger is pressed on the fingerprint detection area 103, the display screen 120 emits a beam of light to the target finger above the fingerprint detection area 103. The light is reflected on the surface of the finger to form reflected light or is scattered inside the finger. Form scattered light. In related patent applications, for ease of description, the above-mentioned reflected light and scattered light are collectively referred to as reflected light. Because the ridge and valley of the fingerprint have different light reflection capabilities, the reflected light from the fingerprint ridge and the emitted light from the fingerprint ridge have different light intensities. After the reflected light passes through the optical components, it is affected by the optical fingerprint. The sensing array in the device 130 receives and converts into a corresponding electrical signal, that is, a fingerprint detection signal; based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, thereby implementing the electronic device 10 Optical fingerprint recognition function.

In other embodiments, the optical fingerprint device 130 may also use a built-in light source or an external light source to provide an optical signal for fingerprint detection. In this case, the optical fingerprint device 130 may be suitable for non-self-luminous display screens, such as liquid crystal display screens or other passively-luminous display screens. Taking a liquid crystal display with a backlight module and a liquid crystal panel as an example, in order to support the under-screen fingerprint detection of the liquid crystal display, the edge area under the protective cover of the electronic device 10, and the optical fingerprint device 130 may The liquid crystal panel or the protective cover is arranged under the edge area and guided by the light path so that the fingerprint detection light can reach the optical fingerprint device 130; or, the optical fingerprint device 130 can also be arranged under the backlight module, and The backlight module allows the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint device 130 by opening holes or other optical designs on film layers such as diffusion sheets, brightness enhancement sheets, and reflective sheets. When the optical fingerprint device 130 adopts a built-in light source or an external light source to provide an optical signal for fingerprint detection, the detection principle is the same as that described above.

It should be understood that, in specific implementation, the electronic device 10 further includes a transparent protective cover, which may be a glass cover or a sapphire cover, which is located above the display screen 120 and covers the electronic The front of the device 10. Because, in the embodiment of the present application, the so-called finger pressing on the display screen 120 actually refers to pressing on the cover plate above the display screen 120 or covering the surface of the protective layer of the cover plate.

On the other hand, in some embodiments, the optical fingerprint device 130 may include only one optical sensor. At this time, the fingerprint detection area 103 of the optical fingerprint device 130 has a small area and a fixed position. Therefore, when the user performs fingerprint input It is necessary to press the finger to a specific position of the fingerprint detection area 103, otherwise the optical fingerprint device 130 may not be able to collect fingerprint images, resulting in poor user experience. In other alternative embodiments, the optical fingerprint device 130 may specifically include a plurality of optical sensors; the plurality of optical sensors may be arranged side by side under the display screen 120 by splicing, and the The sensing area collectively constitutes the fingerprint detection area 103 of the optical fingerprint device 130. In other words, the fingerprint detection area 103 of the optical fingerprint device 130 may include multiple sub-areas, and each sub-area corresponds to the sensing area of one of the optical sensors, so that the fingerprint collection area 103 of the optical fingerprint device 130 can be It extends to the main area of the lower half of the display screen, that is, extends to the area where the finger is habitually pressed, so as to realize the blind fingerprint input operation. Alternatively, when the number of optical sensors is sufficient, the fingerprint detection area 103 can also be extended to half of the display area or even the entire display area, thereby realizing half-screen or full-screen fingerprint detection.

Generally, regardless of whether the optical fingerprint device 130 uses the self-luminous display unit of the display screen 120 or an external light source as the excitation light source for fingerprint detection, the light signal for fingerprint detection emitted by the excitation light source is usually a pure color light signal. The light spot formed by the light signal in the fingerprint detection area 103 is usually a pure color pattern, for example, a white light spot.

Since the refractive index of the optical signal in the optical medium (for example, the lens) is related to the wavelength, the optical signal of different colors will have different propagation paths after being refracted by the lens system, that is, the actual focal length of the optical signal of different colors has Differences, for example, the refractive index of blue light is greater than that of green light, which causes the actual focal length of blue light to be smaller than that of green light, while the refractive index of red light is smaller than that of blue and green light. Therefore, red light The actual focal length of is the largest of the three.

It should be understood that in the embodiments of the present application, the larger the refractive index (or the longer the wavelength) can be considered as the more serious the degree of dispersion. Therefore, among the three primary colors of RGB, blue light has the most serious dispersion degree, followed by green light. The degree of red light dispersion is the lightest.

In view of this, the embodiments of the present application provide a fingerprint detection solution. When designing the light signal emitted by the excitation light source, the light signal corresponding to the light spot in the edge detection area of the fingerprint detection area can be designed as a light signal with a larger actual focal length. , The optical signal corresponding to the light spot in the central detection area of the fingerprint detection area is designed as an optical signal with a smaller actual focal length. In other words, by setting the degree of dispersion of the optical signal corresponding to the spot of the edge detection area to be smaller than the degree of dispersion of the optical signal corresponding to the relationship of the central detection area, for example, the central detection area is preferably a blue spot, and the edge is sequentially transformed into a green spot , And then to the red light spot, which can improve the over-defocusing phenomenon of the edge detection area, making the focal plane closer to the image plane.

FIG. 3 is a schematic diagram of the system structure of a fingerprint detection device 10 provided by an embodiment of the present application. As shown in FIG. 3, the fingerprint detection device 10 may be disposed under the display screen 20 of an electronic device. In the embodiment of the present application, The display screen 20 may correspond to the display screen 120 shown in FIGS. 2A and 2B, and the fingerprint detection area 230 of the display screen 20 may be the fingerprint detection area 103 shown in FIG. 2A. In the embodiment shown in FIG. 3, the display screen 20 may specifically be a self-luminous display (such as an OLED display), and it includes a plurality of self-luminous display units 11 (such as OLED pixels or OLED light sources). The self-luminous display unit 11 is configured to emit light under the driving of a display driving module to make the display screen 20 display a corresponding screen.

Wherein, in the display screen 20, a part of the self-luminous display unit 11 located in the fingerprint detection area 20 can be used as an excitation light source for the fingerprint detection device 10 to perform fingerprint detection, and is used to emit light to the fingerprint detection area 20. The signal is used to form a target pattern in the fingerprint detection area.

Specifically, the excitation light source 11 is used to emit light signals to the fingerprint detection area 230 of the display screen 20, including a first light signal 121 and a second light signal 122, the first light signal 121 and the second light signal The optical signal 122 respectively forms a first pattern 111 and a second pattern 112 on the fingerprint detection area, wherein the first pattern 111 is close to the central detection area of the fingerprint detection area 230, and the second pattern is close to the fingerprint detection area 230, where the dispersion degree of the first optical signal 121 is greater than the dispersion degree of the second optical signal 122, or it can be understood that the refractive index of the first optical signal 121 in the optical component 13 is greater than The refractive index of the second optical signal 122 in the optical component 13, in other words, the actual focal length of the first optical signal 121 is smaller than the actual focal length of the second optical signal 122.

According to the above description, among the three primary colors of RGB, blue light has the strongest degree of dispersion, followed by green light, and red light has the weakest degree of dispersion. Therefore, in the embodiment of the present application, the ratio of the three primary colors of RGB included in the first optical signal 121 and the ratio of the three primary colors of RGB included in the second optical signal 122 can be designed to make the ratio of the first optical signal 121 The degree of dispersion is greater than the degree of dispersion of the second optical signal 122, so that during imaging, it can be ensured that the actual focal length of the second optical signal 122 is greater than the actual focal length of the first optical signal 121, thereby improving the defocusing degree of the edge detection area .

Correspondingly, the target pattern displayed on the fingerprint detection area 230 of the display screen 20 based on the first light signal 121 and the second light signal 122 may include the first pattern 111 and the second pattern The non-pure color pattern 112 (or called the non-pure color light spot), that is, the light spot for fingerprint detection in the embodiment of the present application is a mixed color light spot.

Optionally, in an embodiment of the present application, the first pattern 111 is more bluish than the second pattern 112, and the second pattern 111 is more green or red than the second pattern 112. In other words, the proportion of blue included in the first pattern 111 is greater than the proportion of blue included in the second pattern 112, or the proportion of green included in the first pattern 111 is smaller than that of the second pattern. The proportion of green included in the pattern 112.

Optionally, in the embodiment of the present application, the excitation light source 11 may be implemented by adopting the self-luminous display unit of the display screen 20 in the fingerprint detection area 230, or in other alternative embodiments, the excitation The light source 11 may also be an external light source 14 additionally provided in the fingerprint detection device 10. As shown in FIG. 4, the external light source 14 is also arranged below the display screen 20 for directing the display 20 The fingerprint detection area 230 emits the first light signal 121 and the second light signal 122 to form the first pattern 111 and the second pattern 112 in the fingerprint detection area 230.

Optionally, in some embodiments, the fingerprint detection device 10 may further include:

The optical sensor 12 is configured to receive the reflected light signal formed by the target light signal reflected on the surface of the target object (such as the user's finger) in the fingerprint detection area 230, wherein the reflected light signal can be used as a fingerprint detection signal , Used to determine the user's fingerprint information for subsequent fingerprint identification.

Wherein, the optical sensor 12 may correspond to the optical fingerprint chip of the light detecting part 134 in FIG. 2B, which will not be repeated here.

In the embodiment of the present application, the fingerprint detection device 10 may further include an optical component 13. In the embodiment shown in FIG. 3 or FIG. 4, the optical component 13 may specifically include one or more optical lenses, which may combine The reflected light signal or fingerprint detection signal passing through the display screen 230 is converged or guided to the optical sensor 12. Specifically, the optical component 13 may be the optical component 132 in FIG. 2B, which will not be repeated here.

Optionally, in the embodiment of the present application, taking the self-luminous display unit of the display screen 20 as the excitation light source 11 of the fingerprint detection device 10 as an example, the display drive module may be used to drive the display screen 20 in the location. The ratio and/or gray value of the three primary colors of RGB in the light signal emitted by the self-luminous display unit of the fingerprint detection area 230, so that the dispersion degree of the second light signal 122 is greater than the dispersion degree of the first light signal 121 .

Specifically, the excitation light source 11 may include a red light source, a green light source, and a blue light source, such as a red display unit, a green display unit, and a blue display unit of the display screen 20, which are controlled by the display drive module. The ratio and/or gray value of the three primary colors of RGB in the light signal emitted by the light source can control the dispersion intensity of the light signal emitted to the edge detection area and the center detection area, and at the same time, the edge detection area and the center detection of the fingerprint detection area 230 The pattern formed by the area also has the corresponding gray value and color.

For example, if the fingerprint detection device 10 uses a red light source, a green light source, and a blue light source to emit light signals to the edge detection area and the center detection area as fingerprint detection excitation light when performing fingerprint detection, for example, the display driver The module controls the display screen 20 to emit light at least part of the green display unit, the red display unit and the blue display unit of the fingerprint detection area 230 at the same time. In this case, the display driving module can control the fingerprint detection area 230 respectively. The luminous ratio (that is, the ratio of the three primary colors of RGB) and/or the gray value of the red display unit, the green display unit, and the blue display unit in the center detection area and the edge detection area of the detection area 230, so that the edge detection area The degree of dispersion of the optical signal is smaller than the degree of dispersion of the optical signal in the central detection area.

In the fingerprint detection device 10 of the embodiment of the present application, by controlling the excitation light source 11 to emit multiple light signals of different colors or gray values to the fingerprint detection area 20 of the display screen 20, the multiple light signals irradiate Different positions of the fingerprint detection area 230 may form multiple patterns with different colors and gray values.

Optionally, in some embodiments, the degree of dispersion of the plurality of optical signals is reduced in order from the center of the fingerprint detection area from near to far. In other words, the refractive index of the plurality of optical signals is reduced in order. In other words, the actual focal lengths of the multiple optical signals are sequentially increased, so that the optical signal corresponding to the edge detection area has a larger actual focal length, thereby ensuring that the focal plane of the optical fingerprint is closer to the image plane of the optical sensor.

As an optional embodiment, according to the order from the nearer to the farthest from the center of the fingerprint detection area, the multiple patterns are blue light spots, cyan light spots, green light spots and yellow light spots in order.

Optionally, in some embodiments, as shown in FIG. 5, the light spot formed by the light signal emitted by the excitation light source 11 in the fingerprint detection area 230 may be circular, elliptical, rectangular, other regular or irregular. Graphics, etc., which are not limited in the embodiment of the present application.

Hereinafter, with reference to FIGS. 6 to 10, the method for determining the optical signals emitted to different areas of the fingerprint detection area will be described in detail.

For ease of description and explanation, taking the lens as an example, the center of the lens is marked as (0,0), the actual focal length of a point (x, y) on the lens is marked as Q, and the actual image distance is marked as d. The focus degree Q _{foc is} shown in formula (1):

Q _foc = |Q/d| Formula (1)

When Q _foc =1, the degree of focus is the best, that is, the image distance is the same as the focal length. When the image distance deviates from the focal length, the defocus phenomenon appears. Correspondingly, the degree of defocus Q _defoc can be expressed as:

Q _defoc =|(dQ)/d| formula (2)

Fig. 6 is a schematic diagram of a fingerprint image collected based on a pure color spot, and Fig. 7 is a comparison diagram of the defocus degree of the focus plane and the image plane based on the pure color spot and the desired degree of defocus. The center of the marked auxiliary line is the origin, the X axis represents the distance from the pixel on the auxiliary line to the center, the unit is um, and the Y axis represents the degree of defocus. Combining Figure 6 and Figure 7, it can be seen that when the focus degree of the center of the image plane reaches 1, at this time, the modulation transfer function (MTF) of the lens is the largest, the image contrast is the largest, and the image in the central area is the clearest. But in the edge area, the degree of defocus is severe and the contrast is poor, so the image in the edge area is blurry.

In order to improve the defocusing degree of the edge area, so that the focus degree Q _{foc of the} focal plane on the image plane is close to 1. According to the above formula (1), it can be known that the d value or the Q value can be adjusted. Since the d value is determined by the physical geometric size, After the optical path structure of the fingerprint detection device is fixed, it is usually not adjustable. Therefore, in the embodiment of the present application, the Q value can be adjusted to improve the defocusing degree of the edge.

In specific implementation, it is necessary to determine the parameters of the light signal emitted to each area in the fingerprint detection area, for example, the ratio of the three primary colors of RGB or the gray value and other parameters, so as to make the actual focal length Q of each point on the lens as far as possible Equal to or close to the image distance d.

The actual focal length Q _NEW of the point (x, y) on the lens is related to the ratio of the three primary colors of RGB in the light signal corresponding to the point, which can be expressed as:

Q _NEW = μ _B Q _B + μ _G Q _G + μ _R Q _R formula (3)

Among them, μ _B is the weight coefficient of blue light in the optical signal, Q _B is the actual focal length of blue light, μ _G is the weight coefficient of green light in the optical signal, Q _G is the actual focal length of green light, and μ _R is the red light in the optical signal. Q _R is the actual focal length of the red light.

Further, according to formula (3), it can be known that the focus degree Q _foc-NEW of this point is:

The actual image distance d of this point is related to the image distance d ₀ of the lens center and the deviation distance of this point from the lens center, which can be expressed as:

The weight coefficient μ of light signals of different colors (chromatic light for short) is positively correlated with the attenuation coefficient α of the three primary color gray values on the object side, the response coefficient β of the pixel unit at the optical sensor end, and the modulation transfer function MTF of the color light. It is: μ=α*β*MTF.

Therefore, by controlling at least one of the above-mentioned α, β, d, and MTF parameters, the actual focal length Q of each point can be controlled to make it equal to or close to the actual image distance d.

Hereinafter, the variation curves of several parameters affecting the focus degree Q _foc-NEW will be described in conjunction with FIGS. 8 to 10.

It can be seen from the above description that the actual image distance d is usually determined by the optical path structure of the fingerprint detection device. Without changing the optical path structure, the actual image distances of different colored lights in different areas are usually fixed. Figure 8 shows the change curve of the actual image distance d of each point on the lens when the center of the auxiliary line marked in Figure 6 is the origin of the X axis, and the drawn RGB three primary colors are at the best focus degree at the image center. Wherein, the X axis of the change curve is the distance from the center of the lens, and Y is the actual distance d. The change curve can be used to calculate the actual image distance d of different colors of light at the best focus degree, and further used to determine in subsequent steps The focus of each point on the lens.

In the embodiment of the present application, the attenuation coefficient α of the brightness of the three primary colors (or the luminous effect of the three primary colors) with the gray value δ can be determined through a large number of experiments, as shown in FIG. 9. It can be seen from Figure 9 that the attenuation coefficient curves of the three primary colors are approximately the same, which can be expressed as the following formula:

α=7E-08δ ³ -5E-06δ ² +0.0005δ-0.0042 formula (6)

In the embodiment of the present application, the response coefficient β of the three primary colors at the sensor end can also be determined through simulation and experimental analysis. For example, the response value of each color light under the same exposure time can be determined, and the normalization process is further performed according to the maximum response value. The normalized response coefficient can be obtained, as shown in Table 1:

Table 1

Shade	Response	Normalized response coefficient
R	60	3.33%
R+G	1193	66.13%
G	1187	65.80%
G+B	1804	100.00%
B	806	44.68%

In the embodiment of this application, the MTF of the three primary colors can be further determined. Specifically, the MTF of the three primary colors of blue, green, and red can be determined through a combination of experiment and simulation, and the MTF curves of the three primary colors can be obtained. The change of Q value is shown in Figure 10. It can be seen from Figure 10 that when the blue light MTF reaches the maximum value, the corresponding Q value is 40μm smaller than the corresponding Q value when the green light reaches the maximum MTF. When the green light MTF reaches the maximum value, the corresponding Q value is higher than that of the red light. The corresponding Q value at the maximum MTF is 20μm smaller.

Based on the above information, d and β and MTF are all determined by the optical path structure of the fingerprint detection device, and are usually not adjustable without changing the optical path structure, while α can be adjusted by changing the gray value of the color light. Therefore, In the embodiment of the present application, it is preferable to adjust the Q value by adjusting the gray values of the three primary colors of RGB, so that Q is closer to d.

Further, an evaluation function is set to determine the best α, for example, as shown in the following formula:

MTF _NEW =α _B β _B d _B MTF _B +α _G β _G d _G MTF _G +α _R β _R d _R MTF _R formula (7)

Among them, the MTF _NEW is the resolution of the lens for the three primary colors, the α _B is the attenuation coefficient of blue light relative to the full gray value, β _B is the response coefficient of the optical sensor to blue light, and d _B is the lens when focusing at the center of the blue light. The actual image distance of a certain point above, MTF _B is the resolution of the lens to blue; the α _G is the attenuation coefficient of the green light relative to the full gray value, β _{G is} the response coefficient of the optical sensor to the green light, d _G is the actual image distance of a certain point on the lens when focusing on the center of the green light, MTF _G is the resolution of the lens to blue; the α _R is the attenuation coefficient of the red light relative to the full gray value, and β _{R is} the The response coefficient of the optical sensor to red light, d _R is the actual image distance of a certain point on the lens when focusing at the center of the red light, and MTF _R is the resolution of the lens to red.

According to the evaluation function, combined with the above-mentioned graphs shown in Figures 8 to 10 and the response coefficients shown in Table 1, for example, MATLAB software can be used to calculate the above formula using an exhaustive method to determine the degree of focus The gray value closest to 1, and then it can be determined that the focus of the entire mixed color spot is optimal, that is, it can be determined that each point on the focal plane is close to the image plane to the greatest extent, the RGB of each area in the fingerprint detection area The gray values of the three primary colors are shown in Figure 11. Among them, the Y axis is the attenuation coefficient of the three primary colors relative to the full gray value, and the X axis is the distance from the center of the fingerprint detection area (or the center of the light spot).

According to the attenuation coefficient curve of the gray value of the light signal at different positions shown in FIG. 11, the light spot pattern formed in the fingerprint detection area 230 can be obtained, as shown in FIG. It can be seen from Figure 12 that the detection area at the center is mainly blue light spot, towards the edge direction, it transitions into cyan light spot, green light spot, and yellow light spot in turn, that is, from the center to the edge, the proportion of blue decreases in turn, and the green light The proportion first increases and then decreases. Since the ambient light includes infrared light, the proportion of red light is relatively low.

FIG. 13 shows a comparison diagram of the focal plane (that is, the modified focal plane) of the optical fingerprint re-determined based on the mixed color spot shown in FIG. 12, the original focal plane (that is, the focal plane before the modification), and the desired focal plane.

According to the image plane and focal plane curves in FIG. 13, the defocus degree curve before and after the modification can be obtained. As shown in FIG. 14, it can be seen from FIG. 14 that the defocus degree of the edge detection area is obviously improved.

Figure 15 shows a comparison of fingerprint images collected based on the pure color spot and the mixed color spot shown in Figure 12, where image a is a fingerprint image collected based on the pure color spot, and image b is based on the mixed color spot collection shown in Figure 12 Fingerprint image. By comparison, it can be seen that the sharpness of the edge area of the fingerprint image collected based on the mixed color spot is greatly improved, and the recognizable area is greatly increased. Further fingerprint recognition based on this fingerprint image can improve the fingerprint recognition rate.

Fig. 16 is a comparison curve based on the system tolerance of the pure color spot (take the green spot as an example) and the mixed color spot. It can be seen that the system tolerance based on the mixed color spot is obviously increased by about 30 μm.

Optionally, in some embodiments, as shown in FIG. 17, the fingerprint detection device 10 may further include:

The processing module 16 is configured to determine the gray values of the three primary colors of RGB in the light signals emitted to different areas of the fingerprint detection area according to at least one of the following: the response coefficient of the optical sensor to the light signals of different colors, and the difference The actual image distance of the light signal of the color in different areas of the optical sensor, the modulation transfer function MTF of the light signal of the three primary colors of the optical sensor, and the attenuation coefficient of the brightness of the light signal of different colors with the gray value.

For the specific process, reference may be made to the relevant description in the foregoing embodiment, and for the sake of brevity, it is not repeated here.

In a specific embodiment, the processing module 16 may be specifically a microprocessor (MCU) configured in the fingerprint detection device 10, or may be an application processor of an electronic device applied by the fingerprint detection device 10 or other applications. Processor or controller.

Optionally, in some embodiments, as shown in FIG. 17, the fingerprint detection device 10 may further include:

The light source driving module 15 is configured to drive the excitation light source 11 to emit corresponding light signals according to the color and gray value of the light signals in each area of the fingerprint detection area 230 determined by the processing module 16 The fingerprint detection area 230 displays a corresponding target pattern, such as the aforementioned mixed color spot.

For example, in an embodiment, the light source driving module 15 may drive the excitation light source 11 to respectively emit the first light signal 121 and the first light signal 121 in the center detection area and the edge detection area of the fingerprint detection area 230. Two optical signals 122, so that the display screen 20 displays a mixed color pattern including the first pattern 111 and the second pattern 112 in the fingerprint detection area 230.

In a specific embodiment, when the excitation light source 11 adopts the self-luminous display unit of the display screen 20, the light source driving module 15 may be specifically a display driving module or a display driving module of an electronic device applied by the fingerprint detection device. driver. In other embodiments, if the excitation light source of the fingerprint detection device 10 adopts the external light source 14 as shown in FIG. 3, the light source driving module 15 may specifically be a light source driver for driving the external light source 14. .

Optionally, in some embodiments, the processing module 16 may also display the target pattern (such as the above-mentioned mixed color spot) in the fingerprint detection area 230 of the display screen 120 according to the user detected by the optical sensor 12 Fingerprint information for follow-up operations such as fingerprint recognition. Wherein, the user's finger may press on the target pattern (such as the above-mentioned mixed color spot) to perform fingerprint input, and the light signal corresponding to the target pattern is reflected on the user's finger and forms a reflected light signal, and the reflected light The signal is used as fingerprint detection light, and after passing through the display screen 120, it is converged by the optical component 13 or guided to the optical sensor 12. Therefore, the optical sensor 12 optically images the fingerprint detection light to obtain the The fingerprint information of the user's finger is provided to the processing module 16 for fingerprint identification and subsequent user identity authentication and other operations. That is, the fingerprint detection device 10 of the embodiment of the present application can also be used for subsequent fingerprint recognition and other operations.

It should be understood that in other alternative embodiments, the processing module 16 may also be integrated with the function of the light source driving module 15, that is, the processing module 16 may also be used to control the color of the light signal emitted by the excitation light source 11. , Gray value and other optical parameters. Under this application scenario, the light source driving module 15 can be omitted.

Above, the device embodiment of the present application is described in detail with reference to Figs. 2 to 17. The method embodiment of the present application is described in detail below with reference to Fig. 18. It should be understood that the method embodiment and the device embodiment correspond to each other, and similar descriptions can be Refer to the device embodiment.

FIG. 18 is a schematic flowchart of a fingerprint detection method according to an embodiment of the present application. It should be understood that the fingerprint detection method 400 can be applied to the fingerprint detection apparatus 10 shown in FIG. 3 or 4, or the electronic device shown in FIG. 19 in. As shown in FIG. 18, the fingerprint detection method 400 may include the following content:

S410: When the user's finger presses the target pattern displayed in the fingerprint detection area of the display screen of the electronic device, detecting the reflected light signal formed by the target light signal corresponding to the target pattern reflected on the user's finger, wherein the target pattern It includes a first pattern and a second pattern. The first pattern is closer to the center of the fingerprint detection area than the second pattern, and the dispersion degree of the first optical signal corresponding to the first pattern is greater than that of the second pattern. The dispersion intensity of the second optical signal corresponding to the pattern;

S420: Acquire fingerprint information of the user's finger according to the reflected light signal.

Optionally, in some embodiments, the target pattern is a light spot including a plurality of patterns, and the degree of dispersion of the optical signal corresponding to the plurality of patterns is in the order from the center of the fingerprint detection area to the farthest. Decrease sequentially.

Optionally, in some embodiments, the multiple patterns are blue light spots, cyan light spots, green light spots, and yellow light spots in the order from near to far from the center of the fingerprint detection area.

Optionally, in some embodiments, the gray values of the three primary colors of red, green, and blue in the optical signals corresponding to the multiple patterns are different.

Optionally, in some embodiments, the plurality of patterns include the first pattern and the second pattern, and the gray value of the blue color in the first pattern is greater than that of the blue color in the second pattern. The gray value of green in the first pattern is smaller than the gray value of green in the second pattern.

Optionally, in some embodiments, the method 400 further includes:

The gray values of the three primary colors of RGB in the light signals emitted to different areas of the fingerprint detection area are determined to form the target pattern in the fingerprint detection area.

Optionally, in some embodiments, the determining the gray values of the three primary colors of red, green, and blue in the light signals emitted to different areas of the fingerprint detection area includes:

According to at least one of the following, determine the gray values of the three primary colors of RGB in the light signals emitted to the different areas of the fingerprint detection area: the response coefficient of the optical sensor to the light signals of different colors, and the light signals of different colors at all The actual image distances of different areas of the optical sensor, the modulation transfer function MTF of the optical sensor for the light signals of the three primary colors, and the attenuation coefficient of the brightness of the light signals of different colors with the gray value.

Optionally, in some embodiments, the target pattern is formed by a target light signal emitted by a light source in the fingerprint detection area, wherein the light source includes at least one of a red light source, a green light source, and a blue light source; Methods also include:

By controlling the gray values of the red, green, and blue RGB primary colors of the first light signal and the second light signal emitted by at least one of the red light source, the green light source, and the blue light source, so that The dispersion degree of the first optical signal is greater than the dispersion intensity of the second optical signal.

Optionally, in some embodiments, the wavelength of the first optical signal is smaller than the wavelength of the second optical signal.

Optionally, in some embodiments, the actual focal length of the first optical signal is smaller than the actual focal length of the second optical signal.

It should be understood that, in the method embodiment of the present application, the size of the sequence number of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not correspond to the difference in the embodiment of the present application. The implementation process constitutes any limitation.

An embodiment of the present application also provides an electronic device 800. As shown in FIG. 19, the electronic device 800 may include a display screen 820 and a fingerprint detection device 810. The fingerprint detection device 810 may be the fingerprint detection device in the foregoing embodiment. 10, and set under the display 820. As an optional embodiment, the display screen 820 has a self-luminous display unit, and the self-luminous display unit can be used as an excitation light source for the fingerprint detection device 10 to perform fingerprint detection. In addition, the fingerprint detection device 810 can be used to execute the content in the method embodiment shown in FIG. 18.

It should be understood that the processor or processing module of the embodiment of the present application may be an integrated circuit chip with signal processing capability. In the implementation process, the steps of the foregoing method embodiments can be completed by hardware integrated logic circuits in the processor or instructions in the form of software. The above-mentioned processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a ready-made programmable gate array (Field Programmable Gate Array, FPGA) or other Programming logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps, and logical block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor or the like. The steps of the method disclosed in combination with the embodiments of the present application may be directly embodied as being executed and completed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the field such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

It can be understood that the electronic device of the embodiment of the present application may further include a memory, and the memory may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. Among them, the non-volatile memory can be Read-Only Memory (ROM), Programmable Read-Only Memory (Programmable ROM, PROM), Erasable Programmable Read-Only Memory (Erasable PROM, EPROM), and Erase programmable read-only memory (Electrically EPROM, EEPROM) or flash memory. The volatile memory may be a random access memory (Random Access Memory, RAM), which is used as an external cache. By way of exemplary but not restrictive description, many forms of RAM are available, such as static random access memory (Static RAM, SRAM), dynamic random access memory (Dynamic RAM, DRAM), synchronous dynamic random access memory (Synchronous DRAM, SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (Double Data Rate SDRAM, DDR SDRAM), Enhanced Synchronous Dynamic Random Access Memory (Enhanced SDRAM, ESDRAM), Synchronous Link Dynamic Random Access Memory (Synchlink DRAM, SLDRAM) ) And Direct Rambus RAM (DR RAM). It should be noted that the memories of the systems and methods described herein are intended to include, but are not limited to, these and any other suitable types of memories.

The embodiment of the present application also proposes a computer-readable storage medium that stores one or more programs, and the one or more programs include instructions. When the instructions are included in a portable electronic device that includes multiple application programs When executed, the portable electronic device can be made to execute the method of the embodiment shown in FIG. 13.

The embodiment of the present application also proposes a computer program, the computer program includes instructions, when the computer program is executed by the computer, the computer can execute the method of the embodiment shown in FIG. 18.

An embodiment of the present application also provides a chip that includes an input and output interface, at least one processor, at least one memory, and a bus. The at least one memory is used to store instructions, and the at least one processor is used to call the at least one memory. To execute the method of the embodiment shown in FIG. 18.

A person of ordinary skill in the art may be aware that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and conciseness of description, the specific working process of the above-described system, device, and unit can refer to the corresponding process in the foregoing method embodiment, which is not repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, device, and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components may be combined or It can be integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

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

If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solution of the present application essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , Including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program code .

The above are only specific implementations of this application, but the protection scope of this application is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in this application. Should be covered within the scope of protection of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims (25)

1. A fingerprint detection method, characterized in that it comprises:

   When the user's finger presses the target pattern displayed in the fingerprint detection area of the display screen of the electronic device, the target light signal corresponding to the target pattern is detected as a reflected light signal formed by the reflection of the user's finger, wherein the target pattern includes the first A pattern and a second pattern, the first pattern is closer to the center of the fingerprint detection area than the second pattern, and the dispersion degree of the first optical signal corresponding to the first pattern is greater than that of the second pattern The dispersion intensity of the corresponding second optical signal;

   Obtaining fingerprint information of the user's finger according to the reflected light signal.
2. The method according to claim 1, wherein the target pattern is a light spot including a plurality of patterns, and the light spots corresponding to the plurality of patterns are in the order from near to far from the center of the fingerprint detection area. The dispersion degree of the signal decreases successively.
3. The method according to claim 2, characterized in that, in the order from nearer to farthest from the center of the fingerprint detection area, the plurality of patterns are blue light spot, cyan light spot, green light spot and yellow light spot in sequence.
4. The method according to claim 2 or 3, wherein the gray values of the three primary colors of red, green, and blue in the optical signals corresponding to the plurality of patterns are different.
5. The method according to claim 4, wherein the gray value of blue in the first pattern is greater than the gray value of blue in the second pattern, and the gray value of green in the first pattern The degree value is smaller than the gray value of green in the second pattern.
6. The method according to any one of claims 1 to 5, wherein the method further comprises:

   The gray values of the three primary colors of RGB in the light signals emitted to different areas of the fingerprint detection area are determined to form the target pattern in the fingerprint detection area.
7. The method according to claim 6, wherein the determining the gray values of the three primary colors of red, green, and blue in the light signals emitted to different areas of the fingerprint detection area comprises:

   According to at least one of the following, determine the gray values of the three primary colors of RGB in the light signals emitted to the different areas of the fingerprint detection area: the response coefficient of the optical sensor to the light signals of different colors, and the light signals of different colors at all The actual image distances of different areas of the optical sensor, the modulation transfer function MTF of the optical sensor for the light signals of the three primary colors, and the attenuation coefficient of the brightness of the light signals of different colors with the gray value.
8. The method according to any one of claims 1 to 7, wherein the target pattern is formed by a target light signal emitted by a light source in the fingerprint detection area, wherein the light source includes a red light source, a green light source, and a blue light source. At least one of the color light sources; the method further includes:

   By controlling the gray values of the RGB three primary colors of the first light signal and the second light signal emitted by at least one of the red light source, the green light source, and the blue light source, so that the first The dispersion degree of an optical signal is greater than the dispersion intensity of the second optical signal.
9. The method according to any one of claims 1 to 8, wherein the wavelength of the first optical signal is smaller than the wavelength of the second optical signal.
10. The method according to any one of claims 1 to 9, wherein the actual focal length of the first optical signal is smaller than the actual focal length of the second optical signal.
11. A fingerprint detection device, which is characterized by comprising an optical component and an optical sensor, the optical component is used to guide or converge fingerprint detection signals to the optical sensor, and the optical sensor is used to detect fingerprints based on the fingerprint detection signal The corresponding fingerprint information;

    Wherein, the fingerprint detection signal is a reflected light signal formed by the reflection of the optical signal corresponding to the target pattern formed in the fingerprint detection area of the display screen on the user's finger, and the target pattern includes a first pattern and a second pattern. The first pattern is closer to the center of the fingerprint detection area than the second pattern, and the dispersion degree of the first optical signal corresponding to the first pattern is greater than the dispersion intensity of the second optical signal corresponding to the second pattern .
12. The fingerprint detection device according to claim 11, wherein the target pattern is a light spot that includes a plurality of patterns, and the plurality of patterns correspond to the center of the fingerprint detection area in an order from near to far. The degree of dispersion of the optical signal gradually decreases.
13. The fingerprint detection device according to claim 12, wherein the plurality of patterns are blue light spot, cyan light spot, green light spot and yellow light spot in order from the center of the fingerprint detection area from near to far. .
14. The fingerprint detection device according to claim 12 or 13, wherein the gray values of the three primary colors of red, green, and blue in the optical signals corresponding to the plurality of patterns are different.
15. The fingerprint detection device according to claim 14, wherein the gray value of blue in the first pattern is greater than the gray value of blue in the second pattern, and the green in the first pattern The gray value of is smaller than the gray value of green in the second pattern.
16. The fingerprint detection device according to any one of claims 11 to 15, wherein the target pattern is formed by a target light signal emitted by a light source in the fingerprint detection area, wherein the light source includes a red light source and a green light source. And at least one of the blue light sources.
17. The fingerprint detection device of claim 16, wherein the fingerprint detection device further comprises:

    The light source driving module is used to drive the light source to emit the first light signal and the second light signal in the center detection area and the edge detection area of the fingerprint detection area, so that the The fingerprint detection area respectively displays the first pattern and the second pattern.
18. The fingerprint detection device according to claim 17, wherein the light source driving module is specifically configured to:

    By controlling the gray values of the RGB three primary colors of the first light signal and the second light signal emitted by at least one of the red light source, the green light source, and the blue light source, so that the first The dispersion degree of an optical signal is greater than the dispersion intensity of the second optical signal.
19. The fingerprint detection device according to any one of claims 16 to 18, wherein the light source is a partial self-luminous display unit of the display screen in the fingerprint detection area, and the red light source, the The green light source and the blue light source are respectively a red display unit, a green display unit and a blue display unit of the display screen.
20. The fingerprint detection device according to claim 19, wherein the light source driving module is a display driving module or a display driver for driving the display screen for screen display.
21. The fingerprint detection device according to any one of claims 16 to 18, wherein the light source is an external light source, and the external light source is arranged below the display screen.
22. The fingerprint detection device according to any one of claims 11 to 21, wherein the fingerprint detection device further comprises:

    The processing module is used to determine the gray values of the three primary colors of RGB in the light signals emitted to different areas of the fingerprint detection area, so as to form the target pattern in the fingerprint detection area.
23. The fingerprint detection device according to claim 22, wherein the processing module is specifically configured to:

    According to at least one of the following, determine the gray values of the three primary colors of RGB in the light signals emitted to the different areas of the fingerprint detection area: the response coefficient of the optical sensor to the light signals of different colors, and the light signals of different colors at all The actual image distances of different areas of the optical sensor, the modulation transfer function MTF of the optical sensor for the light signals of the three primary colors, and the attenuation coefficient of the brightness of the light signals of different colors with the gray value.
24. The fingerprint detection device according to any one of claims 11 to 23, wherein the optical component includes one or more lenses, and the refractive index of the first optical signal in the lens is greater than that of the first optical signal. The refractive index of two optical signals in the lens.
25. An electronic device, comprising a display screen and a fingerprint detection device arranged below the display screen, wherein the fingerprint detection device is the fingerprint detection device according to any one of claims 11 to 24.

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