Light source group, image receiver, image acquisition device and electronic equipment

Abstract

The utility model provides a light source group, an image receiver, an image acquisition device and electronic equipment, and relates to the technical field of biological recognition, the light source group comprises at least two light sources, each light source is used for emitting polarized light with the polarization degree not equal to 0, and the polarized light emitted by the light source group has at least two polarization directions; the polarized light in at least two polarization directions is reflected by the target object and then carries polarization information corresponding to the contour surface of the target object to sequentially enter the image sensor. The polarized light emitted by each light source in the light source group is optimized, so that the structure of the light source group is simplified, when the light source group is applied to three-dimensional imaging, target object recognition or anti-counterfeiting recognition and other schemes, the schemes can be simplified, and accurate face contour reconstruction and recognition precision improvement are realized with a relatively simple scheme and relatively low cost.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 2024112594822, filed on September 9, 2024, entitled "An Image Acquisition Device, Electronic Device and Face Recognition Method", and to Chinese Patent Application No. 2024222080638, filed on September 9, 2024, entitled "An Image Acquisition Device and Electronic Device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of biometric technology, and more specifically, to a light source assembly, an image receiver, an image acquisition device, and an electronic device. Background Technology

[0004] With the development of portable terminal devices, the application of biometric technology is becoming increasingly widespread and in-depth. Taking electronic devices as an example, fingerprint recognition and facial recognition are increasingly used in device screen wake-up and identity authentication steps in various programs, improving device security and the flexibility of usage.

[0005] Currently, the main solutions for facial recognition include binocular vision, time-of-flight, and structured light. Binocular vision's reconstruction accuracy is directly proportional to the camera baseline length, limiting its application. Time-of-flight cameras are relatively expensive and limited by temporal resolution, resulting in low 3D imaging accuracy. While structured light offers high imaging accuracy, its slow response time and low frame rate, along with decreasing accuracy with increasing imaging distance, have led to the gradual development of polarization-based 3D imaging technology for facial recognition. However, its implementation is typically complex, resulting in high costs. Utility Model Content

[0006] The purpose of this application is to address the shortcomings of the prior art by providing a light source assembly, an image receiver, an image acquisition device, and an electronic device.

[0007] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0008] In one aspect of this application, a light source group is provided, including at least two light sources, each light source being used to emit polarized light with a polarization degree not equal to 0, and the polarized light emitted by the light source group having at least two polarization directions, wherein the polarized light with at least two polarization directions, after being reflected by the target object, carries polarization information corresponding to the contour surface of the target object and is sequentially incident on an image sensor.

[0009] Optionally, the at least one light source satisfies the following condition:

[0010] The light source comprises a light emitting element, and the light emitting element is configured to emit the polarized light emitted by the light source.

[0011] Alternatively, the light source comprises a light emitting element and a polarizing element, and the light emitted by the light emitting element is modulated by the polarizing element to form the polarized light emitted by the light source.

[0012] Optionally, the light emitting element is a laser, and a diffusion element is further arranged on the light emitting side of the laser, and the diffusion element is configured to expand the light emitting angle of the laser.

[0013] Optionally, when the light source comprises a light emitting element and a polarizing element, and the light emitting element is a laser, the polarizing element is located between the laser and the diffusion element.

[0014] Optionally, when the light source comprises a light emitting element and a polarizing element, and the light emitting element is a laser, the light source is a packaged light source, the packaged light source further comprises a packaging substrate and a support structure, the laser is fixed to the packaging substrate, the support structure is fixed to the packaging substrate and located beside the laser, the polarizing element and the diffusion element are separate components, and the polarizing element and the diffusion element are respectively fixed to the support structure, wherein the polarizing element is located between the laser and the diffusion element, or the diffusion element is located between the laser and the polarizing element.

[0015] Optionally, when the light source comprises a light emitting element and a polarizing element, and the light emitting element is a laser, the light source is a packaged light source, the packaged light source further comprises a substrate, a packaging substrate and a support structure, the laser is fixed to the packaging substrate, the support structure is fixed to the packaging substrate and located beside the laser, the polarizing element is a polarizing unit on one side surface of the substrate, the diffusion element is a diffusion unit on the other side surface of the substrate, and the substrate is fixed to the support structure, wherein the polarizing unit is located between the laser and the diffusion unit, or the diffusion unit is located between the laser and the polarizing unit.

[0016] Optionally, the degree of polarization of the polarized light emitted by the at least one light source is greater than 0.1.

[0017] Optionally, the maximum polarization directions of the polarized light emitted by the at least two light sources are different.

[0018] Optionally, the light emitting wave bands of the at least two light sources are the same.

[0019] Optionally, the light emitting wave band of the at least one light source is 940 nm.

[0020] Optionally, the at least two light sources are distributed on the same side or opposite sides of the image sensor.

[0021] Optionally, the polarized light emitted by the light source group has at least two polarized directions of polarized light forming a first included angle, or any two polarized directions of polarized light forming a first included angle, and the first included angle is in the range of [45°, 135°].

[0022] Optionally, the first included angle is in the range of [45°, 90°) and / or (90°, 135°].

[0023] In another aspect of the embodiment of the present application, an image receiver is provided, which comprises an image sensor and a polarized device, the image sensor comprises an array of light sensing units, and the polarized device is located on the light receiving side of the array of light sensing units, the polarized direction of the polarized device forms a second included angle with one of the polarized directions of the polarized light emitted by the light source group, the light source group comprises at least two light sources, each of which is used to emit polarized light with a polarization degree not equal to 0, and the polarized light emitted by the light source group has at least two polarized directions, and the at least two polarized directions of polarized light carry polarized information corresponding to the profile of the target object in sequence after being reflected by the target object and then incident on the image sensor.

[0024] Optionally, the target angle is 5°, 10°, 15°, 20°, 25° or 30°.

[0025] Optionally, the light source group comprises two light sources, and the polarized directions of the polarized light emitted by the two light sources are perpendicular to each other.

[0026] Optionally, the polarized direction of the polarized device is the same as one of the polarized directions of the polarized light emitted by the light source group.

[0027] The polarized light emitted by the light source group has at least two polarized directions of polarized light forming a first included angle, or any two polarized directions of polarized light forming a first included angle, and the first included angle is in the range of [45°, 90°) and (90°, 135°].

[0028] Optionally, the image receiver further comprises a narrow bandpass filter, and the narrow bandpass filter is located on the light receiving side of the array of light sensing units, and the bandpass wavelength range of the narrow bandpass filter covers the light emitting wavelength range of the light source group.

[0029] Optionally, when the light emitting wavelength range of the light source group is 940 nm, the bandpass wavelength range of the narrow bandpass filter is 940 nm±10 nm.

[0030] Optionally, the polarized device is separate from the image sensor, or the polarized device is integrated inside the image sensor.

[0031] Optionally, the polarized directions of the polarized light emitted by the two light sources are perpendicular to each other, and the polarized direction of the polarized device is perpendicular to the polarized direction of the polarized light emitted by one of the two light sources.

[0032] Optionally, the polarization directions of the polarized light emitted by the two light sources are vertical and horizontal respectively, and the polarization direction of the polarization device is vertical or horizontal.

[0033] Optionally, the polarization directions of the polarized light emitted by the two light sources are vertical (0-degree polarization) and horizontal (90-degree polarization) respectively, and the polarization direction of the polarization device is vertical (0-degree polarization) or horizontal (90-degree polarization).

[0034] In another aspect of the embodiments of the present application, an image acquisition device is provided, comprising an out-light device and a receiving device arranged along a light path, wherein the out-light device is any one of the light source groups described above, and / or the receiving device is any one of the image receivers described above.

[0035] In another aspect of the embodiments of the present application, an electronic device is provided, comprising a device main body and any one of the image acquisition devices described above, wherein the image acquisition device is arranged on the device main body.

[0036] Optionally, the device main body comprises a display screen, and the image acquisition device is arranged below the display screen.

[0037] The beneficial effects of the present application include:

[0038] The present application provides a light source group, an image receiver, an image acquisition device and an electronic device, the light source group comprising at least two light sources, each light source being configured to emit polarized light with a polarization degree not equal to 0, and the polarized light emitted by the light source group having at least two polarization directions, the polarized light of the at least two polarization directions carrying polarization information corresponding to the profile of the target object in sequence after being reflected by the target object and being incident on an image sensor. By optimizing the polarized light emitted by each light source in the light source group, the structure of the light source group is simplified, and when it is applied to a scheme of three-dimensional imaging, target object identification or anti-counterfeiting identification, etc., the scheme can be simplified, and accurate reconstruction of a human face profile can be achieved with a relatively simple scheme and at a relatively low cost, thereby improving the identification accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0040] Figure 1 Structure schematic diagram of an image acquisition device provided by the embodiments of the present application;

[0041] Figure 2 Schematic diagram of polarization state change of the same polarized light on surfaces of different materials;

[0042] Figure 3 A schematic diagram of the polarization state change of the same polarized light with different incident angles for the same white paper;

[0043] Figure 4 A structure schematic diagram of an image acquisition device provided by an embodiment of the present application;

[0044] Figure 5 A structure schematic diagram of an image acquisition device provided by an embodiment of the present application;

[0045] Figure 6 A structure schematic diagram of a light source provided by an embodiment of the present application;

[0046] Figure 7 A structure schematic diagram of a packaged light source provided by an embodiment of the present application;

[0047] Figure 8 A structure schematic diagram of a packaged light source provided by an embodiment of the present application;

[0048] Figure 9 A distribution schematic diagram of three image acquisition devices provided by an embodiment of the present application;

[0049] Figure 10 A structure schematic diagram of an image acquisition device provided by an embodiment of the present application;

[0050] Figure 11 A structure schematic diagram of an electronic device provided by an embodiment of the present application.

[0051] Icon: 100-face; 200-first light source; 210-first light emitting element; 220-first polarizing element; 230-diffusion element; 300-second light source; 310-second light emitting element; 320-second polarizing element; 400-image sensor; 410-photosensitive unit array; 420-lens assembly; 500-packaged light source; 510-laser; 520-packaged board; 530-supporting structure; 541-diffusion unit; 542-polarization unit; 10-image acquisition device; 21-middle frame; 22-display screen. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments of the present application. It should be noted that, in the case of no conflict, each feature in the embodiments of the present application can be combined with each other, and the combined embodiment is still within the protection scope of the present application.

[0053] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0054] In the description of the present application, it should also be noted that unless otherwise explicitly specified and limited, the terms "set", "mount", "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0055] It should be understood that the target object in the present application can be Figure 1 The face 100 in the middle, the local part (such as the cheek, the nose, the eye) in the face 100, of course, is not limited to this, and can also be other objects with three-dimensional size or living body attribute, such as fingers, palms, etc. For the convenience of understanding, the face 100 is taken as an example for description in the following, and those skilled in the art should be able to clearly understand the changed scheme by referring to the following examples when the target object changes.

[0056] In an aspect of the present application, a light source group is provided, which can be applied to three-dimensional imaging, target object recognition or anti-counterfeiting identification and the like. By reasonably setting the light source group, it can directly emit polarized light meeting the requirements of three-dimensional imaging, target object recognition or anti-counterfeiting identification and the like when it has an appropriate number of light sources, simplifying the structure of the light source side in the three-dimensional imaging, target object recognition or anti-counterfeiting identification and the like, and cooperating with the receiving side, the three-dimensional imaging, target object recognition or anti-counterfeiting identification and the like can also be simplified.

[0057] In order to better understand the light source group, the following will be described in combination with the scene of image information collection and the image sensor of the receiving side.

[0058] Please refer to Figure 1 , which shows a light source group and an image sensor, that is, an image collection device. The light source group can emit polarized light towards the face 100, and the image sensor can receive the polarized light after it is reflected by the face 100, so as to collect the face image information, which is convenient for face recognition.

[0059] The light source group includes at least two light sources, each of which can emit polarized light. Of course, the number of light sources included in the light source group can be reasonably set according to actual needs, such as the light source group including two light sources, and the two light sources are used to respectively emit polarized light (for the convenience of description, the following are respectively referred to as the first light source 200 and the second light source 300, and correspondingly, the first light source 200 emits the first polarized light, and the second light source 300 emits the second polarized light). Based on this setting of the light source group, the number of required light sources can be optimized, so that the image acquisition device only includes two light sources, which helps to simplify the image acquisition device and facilitate its miniaturization. At the same time, it is also convenient for the image acquisition device to form two images according to the polarized light it receives, which can also simplify the number of images formed by the image acquisition device and reduce the data processing amount of the image acquisition device. Similarly, the light source group can also include three, four, five or other numbers of light sources. It should be understood that when the number of light sources is more than two, the working mode and principle of the light source group are similar to those of two light sources. In addition, when the number of light sources is large, the number of polarization directions included in the polarized light is larger, but the volume of the light source group may also increase, so reasonable selection can be made according to needs.

[0060] More specifically, when the number of light sources in the light source group is more than two, the following multiple cases exist: for example, when the number of polarization directions of the polarized light emitted by the light source group is equal to the number of light sources in the light source group, it means that the polarization directions of the polarized light emitted by any two light sources are different; for another example, when the number of polarization directions of the polarized light emitted by the light source group is less than the number of light sources in the light source group, it means that the light source group includes a first number of light sources and a second number of light sources, the first number is equal to the number of polarization directions of the polarized light emitted by the light source group, and the polarization direction of the polarized light emitted by the second number of light sources repeats one or more polarization directions of the polarized light emitted by the first number of light sources. In this way, the number of polarized light with the same polarization direction can be increased, so that it has a higher light intensity.

[0061] After optimization, the image acquisition device also needs to ensure the accuracy of the face image information it collects, so that the polarized light emitted by each of the at least two light sources satisfies the following conditions: the degree of polarization of the polarized light emitted by each light source is not equal to 0, and the polarized light emitted by the light source group has at least two polarization directions, that is, the polarized light emitted by each of the two light sources included in the light source group satisfies the following conditions: the degree of polarization of the first polarized light and the second polarized light is not equal to 0, and the polarization direction of the first polarized light and the second polarized light is different (that is, the polarized light emitted by the light source group has two different polarization directions). This helps the image acquisition device to more accurately realize the collection of face image information and facilitate accurate face recognition.

[0062] Specifically, it should be first understood that polarized light has the following characteristics: when the polarized light is transmitted to the surface of the target object and reflected by the target object, the polarization state of each light ray in the polarized light changes, and the change amount of the polarization state of each light ray is related to the material of the surface of the target object and the incident angle (spatial position) of each point in the profile surface of the target object, such as Figure 2 The figure shows the change of the polarization state of the same polarized light on different material surfaces. When the same polarized light is vertically incident on different material surfaces, by rotating the polarizer by 360 degrees to receive the reflected polarized light, it can be seen that the corresponding change of the polarization state is different when the material of the surface of the target object is different; for example Figure 3 The figure shows the change of the polarization state of the same polarized light on different material surfaces. When the same polarized light is vertically incident on different material surfaces, by rotating the polarizer by 360 degrees to receive the reflected polarized light, it can be seen that the corresponding change of the polarization state is different when the material of the surface of the target object is different; for example

[0063] Back to Figure 1 The image acquisition device shown in the figure, the first light source 200 and the second light source 300 respectively emit polarized light with different polarization degrees to the face 100, which facilitates the use of the characteristics of the aforementioned polarized light, wherein based on the difference of the spatial position of each point in the profile surface of the face 100 (the incident angle of the polarized light at different points is different) and the surface material of the face 100, the polarized light reflected by the face 100 will carry the polarization information corresponding to the profile surface of the target object, that is, the first polarized light will carry the polarization information corresponding to the profile surface of the target object after being reflected by the face 100, and the second polarized light will also carry the polarization information corresponding to the profile surface of the target object after being reflected by the face 100, and the two are incident on the image sensor 400 in time sequence, which facilitates the image sensor 400 to generate two polarization images (i.e. face image information) according to the incident order of the two. Since the polarization directions of the first polarized light and the second polarized light are different, the information of the face 100 in the depth direction (such as profile information or living body information) can be obtained by analyzing the difference between the two polarization images, and based on this, the profile surface of the face can also be reconstructed more accurately, which is helpful for face recognition with high precision. Of course, when the number of polarization directions of the polarized light emitted by the light source group is greater than 2, more polarized light with different polarization directions will be irradiated to the face in time sequence, and the image sensor 400 will also generate a corresponding number of polarization images (i.e. face image information) according to the incident order.

[0064] It should be understood that the face image information collected by the image collection device can be used to realize face recognition, including face matching and / or anti-counterfeiting identification. The face matching refers to whether the face to be verified and the correct face pre-recorded in the database are the same person (generally judged by calculating the similarity), and the correct face is also called a face template or a database image. The anti-counterfeiting identification refers to whether the face to be verified is a real face or a fake object such as a photo, a video, a face silicone mold, and the like.

[0065] Therefore, the image collection device simplifies the three-dimensional imaging, target object recognition, or anti-counterfeiting identification scheme from the aspects of software and hardware, so that the image collection device can accurately reconstruct the face contour with a relatively simple scheme and at a relatively low cost, and improve the recognition accuracy.

[0066] When the first light source 200 and the second light source 300 emit polarized light, the first polarized light and the second polarized light can reach the face 100 in time sequence and cannot irradiate the face 100 at the same time, which facilitates the separation of the first polarized light and the second polarized light in the time dimension, and facilitates that the two polarized images formed by the image sensor 400 correspond to the first polarized light and the second polarized light one by one. For example, the first light source 200 emits the first polarized light first, delays for a certain time, then the first light source 200 is turned off, and then the second light source 300 emits the second polarized light. For another example, the first light source 200 and the second light source 300 are turned on at the same time, but are not turned off at the same time, wherein the optical paths of the first polarized light and the second polarized light transmitted to the face 100 are different, so that the two polarized lights can also be separated in the time dimension, and the mixing of the two polarized lights to cause unfavorable recognition conditions can be avoided. When the number of polarized directions of the polarized light emitted by the light source group is further increased, for example, greater than 2, the polarized light of different polarized directions should also be separated in the time dimension (the separation mode of any two polarized directions of polarized light can be set according to the above-mentioned modes), so as to avoid the mixing to cause unfavorable recognition conditions.

[0067] When the light sources of the light source group emit polarized light, at least one light source satisfies the following conditions: the light source includes a light emitting element, and the light emitting element is used to emit the polarized light emitted by the light source; or the light source includes a light emitting element and a polarizing element, and the light emitted by the light emitting element is modulated by the polarizing element to form the polarized light emitted by the light source.

[0068] For example, when two light sources of the light source group emit polarized light, a plurality of schemes can be used:

[0069] In some possible implementation manners, the first light source 200 comprises a light emitting element (referred to as a first light emitting element 210 for the purpose of distinguishing from the second light source 300), and the first light emitting element 210 is capable of directly emitting the first polarized light. Alternatively, the first light source 200 comprises the first light emitting element 210 and a polarizing element (referred to as a first polarizing element 220 for the purpose of distinguishing from the second light source 300), and the first polarizing element 220 is located on the light emitting side of the first light emitting element 210. The light emitted by the first light emitting element 210 is modulated by the first polarizing element 220 to form the first polarized light.

[0070] In some possible implementation manners, the second light source 300 comprises a light emitting element (referred to as a second light emitting element 310 for the purpose of distinguishing from the first light source 200), and the second light emitting element 310 is capable of directly emitting the second polarized light. Alternatively, the second light source 300 comprises the second light emitting element 310 and a polarizing element (referred to as a second polarizing element 320 for the purpose of distinguishing from the first light source 200), and the second polarizing element 320 is located on the light emitting side of the second light emitting element 310. The light emitted by the second light emitting element 310 is modulated by the second polarizing element 320 to form the second polarized light.

[0071] Therefore, by combining the two schemes of the first light source 200 and the second light source 300, four different schemes can be formed, and two of them will be described below in combination with the accompanying drawings:

[0072] Scheme One

[0073] Please refer to Figure 4 The first light source 200 comprises the first light emitting element 210, and the first light emitting element 210 is capable of directly emitting the first polarized light. The second light source 300 comprises the second light emitting element 310, and the second light emitting element 310 is capable of directly emitting the second polarized light. If the degree of polarization of the polarized light emitted by the first light emitting element 210 and / or the second light emitting element 310 itself is greater than a target threshold value (for example, 0.1 or 0.2), no additional polarizing element is needed.

[0074] Scheme Two

[0075] Please refer to Figure 5The first light source 200 comprises a first light emitting element 210 and a first polarizing element 220. The light (natural light or non-first polarized light) emitted by the first light emitting element 210 is modulated by the first polarizing element 220 to form first polarized light. The second light source 300 comprises a second light emitting element 310 and a second polarizing element 320. The light (natural light or non-second polarized light) emitted by the second light emitting element 310 is modulated by the second polarizing element 320 to form second polarized light. If the polarization degree of the polarized light emitted by the first light emitting element 210 and / or the second light emitting element 310 is less than or equal to a target threshold value (for example, 0.1 or 0.2), an additional polarizing element is needed to make the polarization degree of the polarized light emitted by the light source greater than the target threshold value.

[0076] In some possible implementations, the aforementioned first polarizing element 220 and / or the second polarizing element 320 is a polarizing sheet, such as a linear polarizing sheet. In this way, the first polarized light and the second polarized light can both be linear polarized light. In addition, when the first light emitting element 210 included in the first light source 200 directly emits first polarized light and / or the second light emitting element 310 included in the second light source 300 directly emits second polarized light, the first polarized light and the second polarized light can both be linear polarized light.

[0077] In some possible implementations, the aforementioned first light emitting element 210 and / or the second light emitting element 310 comprises, but is not limited to, an LED element, a laser, and the like. The laser can be a vertical-cavity surface-emitting laser (VCSEL) or an edge-emitting semiconductor laser, and the like.

[0078] When the light emitting types of the first light emitting element 210 and / or the second light emitting element 310 are different, the light emitting characteristics thereof are also different. For example, when the first light emitting element 210 and / or the second light emitting element 310 is a laser, the light emitting angle thereof is usually small due to the good directivity of the laser. In order to make the light beam emitted by the light source group better cover the target object, a diffusion element 230, such as a diffusion plate, can be additionally arranged on the light emitting side of the laser to expand the light emitting angle of the laser by the diffusion element 230.

[0079] When the first light source 200 comprises the first light emitting element 210 (being a laser 510), the first polarizing element 220 and the diffusion element 230, the first polarizing element 220 can be arranged between the laser and the diffusion element 230, or the diffusion element 230 can be arranged between the laser and the first polarizing element 220. Similarly, when the second light source 300 comprises the second light emitting element 310 (being a laser), the second polarizing element 320 and the diffusion element 230, the second polarizing element 320 can be arranged between the laser and the diffusion element 230, or the diffusion element 230 can be arranged between the laser and the second polarizing element 320.

[0080] Please refer to Figure 6 When the first polarizing element 220 has a requirement on the incident angle of light, the laser, the first polarizing element 220 and the diffusion element 230 can be arranged in sequence along the light path, so that the light emitted by the laser (small light emitting angle) is first polarized by the first polarizing element 220, and then diffused by the diffusion element 230 (to enlarge the light emitting angle), so as to meet the requirement that the incident angle of light cannot be too large for the first polarizing element 220. For example, when the first polarizing element 220 is a metal grating, it requires that the incident angle of light cannot be too large, otherwise the modulation effect on the incident light will be affected, therefore, the small-angle light emitted by the laser can be first modulated by the first polarizing element 220, and then diffused by the diffusion element 230. Similarly, when the second polarizing element 320 also has a requirement on the incident angle of light, the laser, the second polarizing element 320 and the diffusion element 230 can also be arranged in sequence along the light path.

[0081] At least one light source in the light source group can be a packaged light source, for example, the first light source 200 can be a packaged light source. The structure of the packaged light source can be various, for the convenience of understanding, the following two examples are given:

[0082] Example one

[0083] When the first light source 200 comprises the first light emitting element 210 and other elements (the first polarizing element 220 and / or the diffusion element 230), the first light source 200 can be a packaged light source. For example Figure 7As shown, the first light source 200 is a packaged light source 500, which comprises the first light emitting element 210 (a laser 510), the first polarizing element 220, the diffusion element 230, a packaging substrate 520 and a support structure 530. The laser 510 is fixed to the packaging substrate 520, and the support structure 530 is fixed to the packaging substrate 520 and located beside the laser 510. The first polarizing element 220 and the diffusion element 230 are separate components, and the first polarizing element 220 and the diffusion element 230 are respectively fixed to the support structure 530. The first polarizing element 220 is located between the laser 510 and the diffusion element 230. More specifically, the support structure 530 can be a multi-stage stepped structure, and the stepped surface of each stage can be fixed with a component, such as Figure 7 As shown, the support structure 530 comprises at least two stepped surfaces, wherein the first polarizing element 220 is lapped and fixed to the stepped surface of one stage, and the diffusion element 230 is lapped and fixed to the stepped surface of another stage.

[0084] Of course, in some other embodiments of the packaged light source 500, the difference from the above-mentioned scheme is that the diffusion element 230 can also be located between the laser 510 and the first polarizing element 220. Figure 7

[0085] Example II

[0086] When the first light source 200 comprises the first light emitting element 210 and other components (the first polarizing element 220 and / or the diffusion element 230), the first light source 200 can be a packaged light source. For example, Figure 8 As shown, the first light source 200 is a packaged light source 500, which comprises the first light emitting element 210 (a laser 510), the first polarizing element 220, the diffusion element 230, a substrate, a packaging substrate 520 and a support structure 530. The first polarizing element 220 is a polarizing unit 542 on one side surface of the substrate, and the diffusion element 230 is a diffusion unit 541 on the other side surface of the substrate. Therefore, the first polarizing element 220 and the diffusion element 230 are integrated components integrated on the same substrate, which is helpful for miniaturization of the packaged light source 500. The laser 510 is fixed to the packaging substrate 520, and the support structure 530 is fixed to the packaging substrate 520 and located beside the laser 510. The substrate is fixed to the support structure 530, the diffusion unit 541 is located on the upper surface of the substrate, and the polarizing unit 542 is located on the lower surface of the substrate, i.e. the structure that the first polarizing element 220 is located between the laser 510 and the diffusion element 230. More specifically, the support structure 530 can be a multi-stage stepped structure, and the stepped surface of each stage can be fixed with a component, such as Figure 8 As shown, the support structure 530 comprises at least one stepped surface, wherein the substrate is lapped and fixed to the stepped surface of one stage. ​

[0087] Of course, in some other embodiments in which the first light source 200 is a packaged light source, the difference from the scheme shown in FIG. 2A is that the diffusing unit 541 and the polarizing unit 542 can be exchanged in order, i.e., the diffusing unit 541 is located on the lower surface of the substrate, and the polarizing unit 542 is located on the upper surface of the substrate. Figure 8

[0088] The second light source 300 can also be a packaged light source, and the structural form of the packaged light source can also be various. More specific examples can be understood with reference to the examples of the first light source 200 described above, and the difference between the two is that the packaged light source formed by the second light source 300 includes the second light-emitting element 310 and the second polarizing element 320.

[0089] As described above, the light beams emitted by the light sources in the light source group are polarized light, so the degree of polarization of the light sources is not zero. For example, the light beams emitted by the first light source 200 and the second light source 300 are polarized light, so the degrees of polarization of the two light sources are not zero. Among them, the degree of polarization of the polarized light can be represented by P, and P = (I max - I min ) / (I max + I min ), I max is the luminous intensity of the polarized light in the maximum polarization direction, and I min is the luminous intensity of the polarized light in the minimum polarization direction. The polarized light in this formula can be the first polarized light emitted by the first light source 200, or the second polarized light emitted by the second light source 300.

[0090] As also described above, the information (such as contour information or living body information) of the face 100 in the depth direction needs to be obtained by analyzing the difference between two (or more) polarized images, so in order to facilitate the construction of the difference between any two polarized images, the maximum polarization directions of the light beams emitted by the two light sources described above are different.

[0091] In some possible embodiments, the degree of polarization of the polarized light emitted by at least one light source in the light source group is greater than 0.1, such as the degree of polarization of the polarized light emitted by the first light source 200 and / or the second light source 300 is greater than 0.1, so as to better improve the accuracy of acquisition and identification.

[0092] Optionally, at least two light sources are distributed on the same side or opposite sides of the image sensor (the number of light sources distributed on the opposite sides is not required to be equal or unequal). Please refer to Figure 1 、 Figure 4 、 Figure 5 ​In the setting of the positions of the light sources and the image sensor 400, both of the light sources can be located at the sides of the image sensor 400, so that the light source group and the image sensor 400 can be conveniently integrated in the same device body. In the specific setting, the following examples can be adopted:

[0093] One of them: as shown in (a) of Figure 1 , Figure 4 , Figure 5 , Figure 9 (a) or Figure 10 , the first light source 200 and the second light source 300 are located at the opposite sides of the image sensor 400, more specifically, they can be located at the left and right opposite sides as shown in (a) of Figure 9 , or at the upper and lower opposite sides.

[0094] Another of them: as shown in (b) of Figure 9 , the first light source 200 and the second light source 300 are distributed at the adjacent sides of the image sensor 400.

[0095] Still another of them: as shown in (c) of Figure 9 , the first light source 200 and the second light source 300 are distributed at the same side of the image sensor 400.

[0096] In some possible implementations, the light-emitting wave bands of the at least two light sources in the light source group are the same or different, for example, the light-emitting wave bands of the first light source 200 and the second light source 300 can be the same or different.

[0097] In some possible implementations, the polarized light emitted by the light source group has at least two polarization directions, so that for any two different polarized light with different polarization directions: the polarization directions of the two polarized light form a first included angle. Specifically, the polarization directions of the at least two polarized light form the first included angle, or the polarization directions of any two polarized light form the first included angle.

[0098] In some possible implementations, the first included angle ranges from [45°, 135°], in other words, the first included angle ranges from 45° to 135°, i.e. 45°≤ the first included angle≤ 135°. For example, the first included angle ranges from [45°, 90°) and (90°, 135°], in other words, 45°≤ the first included angle < 90°, and / or 90° < the first included angle≤ 135°, more specifically, the first included angle can also be 50°, 60°, 70°, 80°, 100°, 110° or 120°, etc. in the above range.

[0099] In some possible implementations, the light source can be an infrared light source, so that the sensitivity of the human eye can be reduced. For example, the light-emitting wave band of the light source is 940 nm.

[0100] In another aspect of the embodiments, an image receiver is provided, which includes an image sensor and a polarizing device. The image sensor includes an array of light sensing units. The polarizing device is located on the light receiving side of the array of light sensing units, that is, the polarized light reflected by the target object enters the array of light sensing units through the polarizing device. The polarization direction of the polarizing device and the light source group have the following relationship: the polarization direction of the polarizing device and one of the polarization directions of the polarized light emitted by the light source group form a second included angle less than or equal to a target angle. In other words, the light source group can emit polarized light with at least two polarization directions, and among all the polarization directions, there is one polarization direction that forms a second included angle less than or equal to the target angle with the polarization direction of the polarizing device. The light source group can be any of the above light source groups or a light source group other than the above. When it is not any of the above light source groups, it should meet the following conditions: the light source group includes at least two light sources, each of which is used to emit polarized light with a polarization degree not equal to 0, and the polarized light emitted by the light source group has at least two polarization directions. The polarized light with at least two polarization directions carries the polarization information corresponding to the profile of the target object in sequence after being reflected by the target object and entering the image sensor.

[0101] For example, in some possible embodiments, when the light source group can emit polarized light with at least two polarization directions, the polarizing device (which can be a polaroid, a polarizing film or a metal wire grid, for example) has a second included angle less than or equal to the target angle with one of the polarization directions, and has a third included angle greater than the target angle with the other polarization direction. In this way, the image receiver can receive more information from some polarized light and weaken the information received from other polarized light, thereby forming the expected differentiation of different polarization information.

[0102] In some possible embodiments, the target angle is 5°, 10°, 15°, 20°, 25° or 30°. For example, the second included angle less than or equal to the target angle satisfies 0° < the second included angle ≤ 5°, 0° < the second included angle ≤ 10°, 0° < the second included angle ≤ 15°, 0° < the second included angle ≤ 20°, 0° < the second included angle ≤ 25° or 0° < the second included angle ≤ 30°.

[0103] In some possible embodiments, the polarization direction of the polarizing device is the same as one of the polarization directions of the polarized light emitted by the light source group. In this case, the second included angle is equal to 0°.

[0104] In some possible implementation manners, the light source group includes two light sources, and the polarization directions of the polarized light emitted by the two light sources are perpendicular to each other. For example, the polarization directions of the polarized light emitted by the two light sources are the vertical direction and the horizontal direction respectively, and the polarization direction of the polarizing device is the vertical direction or the horizontal direction. For example, the vertical direction polarization is defined as 0-degree polarization, and the horizontal direction polarization is 90-degree polarization. In this way, the polarization directions of the polarized light emitted by the two light sources are maximally different in terms of the polarization angle.

[0105] On this basis, the polarizing device is further used to maximize the difference between the information (for example, polarization information) contained in the two images obtained by the light-receiving unit array during the process of receiving the polarized light: when the polarization direction of the polarized light emitted by one of the light sources is the same as the polarization direction of the polarizing device, the information contained in the image obtained by the light-receiving unit array 410 is the most; and when the polarization direction of the polarized light emitted by the other light source is perpendicular to the polarization direction of the polarizing device, the information contained in the image obtained by the light-receiving unit array 410 is the least, and the information difference between the two polarized images obtained by the image sensor is the largest, which is beneficial to the identification of the target object.

[0106] It should be understood that there can be different implementation manners: for example, the polarization direction of the polarized light emitted by the first light source is the vertical direction, and the polarization direction of the polarized light emitted by the second light source is the horizontal direction; or for example, the polarization direction of the polarized light emitted by the first light source is the horizontal direction, and the polarization direction of the polarized light emitted by the second light source is the vertical direction.

[0107] In some possible implementation manners, the polarization directions of at least two of the polarized light emitted by the light source group form a first included angle, or the polarization directions of any two of the polarized light emitted by the light source group form a first included angle, and the first included angle is in the range of [45°, 90°) and (90°, 135°]. In other words, 45°≤ the first included angle < 90°, and / or 90° < the first included angle ≤ 135°, and more specifically, the first included angle can also be 50°, 60°, 70°, 80°, 100°, 110° or 120°, etc. in the above range.

[0108] In some possible implementation manners, the image acquisition device further includes a narrow-band pass filter, the narrow-band pass filter is located on the light-receiving side of the image sensor 400, and the passband of the narrow-band pass filter covers the light-emitting wavelength range of all the light sources in the light source group, for example, the light-emitting wavelength range of the first light source and the second light source, that is, the first polarized light and the second polarized light can smoothly pass through the narrow-band pass filter after being reflected by the face 100, and then enter the image sensor 400. By arranging the narrow-band pass filter, stray light can be further filtered out, so that interference light does not enter the image sensor 400 to generate a large amount of noise.

[0109] In some possible implementations, the first light source 200 and the second light source 300 can be infrared light sources, thereby reducing the sensitivity of the human eye. Correspondingly, the bandpass band of the narrowband pass filter should include the emission band of the infrared light source. For example, if the emission band of the first light source 200 and / or the second light source 300 is 940nm, and the bandpass band of the narrowband pass filter is 940nm±10nm, the combined use of the two can effectively filter out interfering stray light generated by sunlight.

[0110] In some possible implementations, an optical path guiding structure, such as a lens assembly 420, is also provided on the light receiving side of the image sensor 400. Figure 10 (As shown) or a microlens array, to facilitate modulation of the first and second polarized light after reflection from the face 100 through the optical path guiding structure, thereby improving image quality. When the light receiving side of the image sensor 400 simultaneously has an optical path guiding structure and a narrowband pass filter, the narrowband pass filter can be located between the optical path guiding structure and the image sensor 400, or the optical path guiding structure can be located between the narrowband pass filter and the image sensor 400, or the narrowband pass filter can be placed within the optical path guiding structure, for example... Figure 10 As shown, the optical path guiding structure is the lens assembly 420. The narrow bandpass filter can be located on the light-incident side or the light-outcident side of the lens assembly 420, or the narrow bandpass filter can be located between multiple optical elements in the lens assembly 420.

[0111] In some possible implementations, the image acquisition device also includes a polarization device. The image sensor 400 includes a photosensitive unit array 410, and the polarization device is located on the light receiving side of the photosensitive unit array 410. Thus, after the first polarized light and the second polarized light are reflected by the face 100, they are first modulated into single linearly polarized light by the polarization device, and then received and imaged by the photosensitive unit array 410. By utilizing the characteristic that each point in the face 100 has a different degree of change in the polarization state of the light, the polarization information carried by the light can be obtained by comprehensively analyzing each polarized image, and the degree of change in the polarization state of the light can be obtained by using the polarization information. Then, the normal vector of that position in the face 100 can be determined. By combining this with the position of each receiving pixel in the photosensitive unit array 410, the contour surface of the target object can be reconstructed more accurately, so that the reconstructed contour surface is closer to the actual contour surface of the target object.

[0112] In some possible implementations, the polarization device is separate from the image sensor; or, the polarization device is integrated inside the image sensor.

[0113] Specifically: The image sensor includes a lens assembly 420 and a narrowband pass filter. There are several possible examples regarding the placement of the polarizing device and the narrowband pass filter:

[0114] Example 1

[0115] The polarizing device is located on the side of the lens assembly 420 away from the image sensor, and the narrow-band filter is located between the lens assembly 420 and the image sensor. Therefore, the polarized light is first modulated by the polarizing device, then guided by the lens assembly 420 to the narrow-band filter, and finally enters the image sensor after filtering. In this example, the polarizing device has a micro-nano grating on the surface of the side of the polarizing device close to the lens assembly 420, so as to provide protection for the micro-nano grating. The polarizing device should have a certain gap with the lens assembly 420, so as to avoid damage to the micro-nano grating on the surface of the polarizing device by the lens assembly 420. More specifically, the polarizing device can be located in the lens barrel (mounting the lens assembly) or attached to the top end of the lens barrel.

[0116] In this example, the narrow-band filter and the polarizing device should be separate parts, that is, the narrow-band filter and the polarizing device are two independent elements.

[0117] Example Two

[0118] The polarizing device is located between the narrow-band filter and the image sensor, which can make the polarized light first filtered by the narrow-band filter to improve the signal-to-noise ratio of the light, and then polarized by the polarizing device, which helps to improve the quality of the polarized image. In other words, the stray light other than the light-emitting waveband can be filtered out by the narrow-band filter first, and then polarized by the polarizing device, which is more pure and beneficial to identification.

[0119] In this example, the narrow-band filter and the polarizing device can be separate parts or integrated parts. Specifically, the narrow-band filter and the polarizing device are two independent elements, wherein the narrow-band filter is arranged closer to the lens assembly, and the polarizing device is arranged closer to the image sensor. The polarizing device and the image sensor can be connected in a bridging or surface-pasting manner. For example, the polarizing device and the image sensor are connected in a bridging manner through a bridge structure, and specifically, the bridge structure can be a support column or a support ring, and the periphery of the polarizing device is connected to the image sensor through the bridge structure. In this way, the bridge structure can be used to provide a certain gap between the polarizing device and the image sensor, and the gap can accommodate the micro-nano grating on the polarizing device to avoid damage caused by contact with the surface of the image sensor. For another example, the polarizing device and the image sensor can be connected in a surface-pasting manner. Specifically, the polarizing device also has a protective layer covering the micro-nano grating, which can provide protection for the micro-nano grating through the protective layer (which can be a silicon dioxide layer), and then the protective layer is bonded to the image sensor through an adhesive layer.

[0120] Of course, the narrow-band optical filter and the polarizing device can also be integrated, that is, the narrow-band optical filter is a filter, the narrow-band optical filter and the polarizing device share the same carrier, and the two are no longer separately provided with carriers, but are distributed on opposite surfaces of the carrier.

[0121] Example Three

[0122] The narrow-band optical filter is located between the polarizing device and the image sensor (in other words, the narrow-band optical filter is located between the lens assembly and the narrow-band optical filter), so that the polarized light first passes through the polarizing device and then is filtered by the narrow-band optical filter.

[0123] In this example, the narrow-band optical filter and the polarizing device can also be separate or integrated. The difference from Example Two is that the positions of the narrow-band optical filter and the polarizing device are different.

[0124] In still another aspect of the embodiments of the present application, an image acquisition device is provided, which comprises an out-light device and a receiving device arranged along an optical path, wherein the out-light device is any one of the light source groups described above, and / or the receiving device is any one of the image receivers described above.

[0125] In another aspect of the embodiments of the present application, an electronic device is provided, which comprises a device main body and the image acquisition device 10 described above, and the image acquisition device 10 is arranged in the device main body. The image acquisition device 10 described above can better acquire information of a target object, and cooperate with a controller in the device main body to reconstruct a profile surface of the target object, which helps to improve the recognition accuracy.

[0126] The electronic device can be specifically a mobile phone, a tablet computer, a television, a notebook computer, a smart home device (for example, a smart air conditioner, a smart refrigerator, a smart sound box, a smart electric lamp, or a smart curtain, etc.), a wearable electronic device, a vehicle-mounted device (which can also be referred to as an in-vehicle infotainment), a virtual reality device, etc., and the embodiments of the present application do not make any limitation on this.

[0127] For example Figure 11 As shown, a mobile phone is shown, which comprises a device main body and the image acquisition device 10 described above, and the device main body comprises a back plate, a middle frame 21, a main board, a battery, and a display screen 22, wherein the back plate and the display screen 22 are respectively mounted to opposite sides of the middle frame 21 so as to enclose an internal space, the main board and the battery can be located in the internal space, the battery is used to supply power to the main board, the image acquisition device 10, and the display screen 22, the display screen 22 is provided with an opening, and the opening position is aligned with the positions of the two light sources and the image sensor in the image acquisition device 10, so that the polarized light emitted thereby can smoothly pass through the display screen 22 to propagate to the profile surface of the target object and receive the light reflected by the target object.

[0128] In still another aspect of the embodiments of the present application, a face recognition method is provided, which comprises:

[0129] S10: controlling the second light source to be off and the first light source to emit polarized light, and generating a first polarized image according to the polarized light incident on the image sensor;

[0130] S20: controlling the first light source to be off and the second light source to emit polarized light, and generating a second polarized image according to the polarized light incident on the image sensor;

[0131] S30: performing face recognition according to the first polarized image and the second polarized image, and obtaining a face recognition result, wherein the face recognition includes face matching and / or anti-counterfeiting identification.

[0132] When the user enables the face recognition function, the correct face image information needs to be recorded as the base image first. When recording, the first light source 200 and the second light source 300 respectively emit polarized light with a polarization degree not equal to 0 towards the correct face 100. The polarized light reflected by the correct face carries the polarization information corresponding to the outline of the target object, and the two polarized lights enter the image sensor 400 in time sequence. Thus, the image sensor 400 can generate two base polarized images according to the incident sequence of the two polarized lights, thereby forming the base image.

[0133] When the base image is recorded and the user needs to perform face recognition in the normal use process, the image acquisition device 10 is started, the first light source 200 and the second light source 300 respectively emit polarized light with a polarization degree not equal to 0 towards the face to be verified, and the polarized light enters the image sensor 400 in time sequence. Thus, the image sensor 400 can generate two polarized images according to the incident sequence of the two polarized lights (the polarized images are to be verified, and thus are called to-be-verified polarized images). By analyzing the two to-be-verified polarized images and the base image, the face recognition result can be obtained.

[0134] When the face recognition includes face matching verification, the face recognition result contains the result of whether the face matches (whether it passes) or not. Similarly, when the face recognition includes anti-counterfeiting verification, the face recognition result also contains the result of whether it is a real face or a photo, a video, a face silicone model, or other counterfeit objects. It can be understood that the sequence of S10 and S20 is not limited.

[0135] Optionally, S30 can specifically be: performing two-dimensional face matching verification according to the first polarized image formed first, and obtaining a two-dimensional face matching result; if the two-dimensional face matching result is not passed, it is concluded that the face recognition result is not matched, and if the two-dimensional face matching result is passed, it is concluded that the face recognition result is matched, and then further performing anti-counterfeiting identification according to the first polarized image formed first and the second polarized image formed later.

[0136] Specifically, two-dimensional face matching verification is performed according to the first polarization image formed first, and a two-dimensional face matching result is obtained. In this way, when the two-dimensional face matching result is not passed, it is directly concluded that the face recognition result is not matched, i.e., the subsequent anti-counterfeiting identification is terminated, which helps to save data processing amount.

[0137] Further, if the two-dimensional face matching result is passed, it is concluded that the face recognition result is matched, a to-be-verified depth image is formed according to the code value difference of the same pixel position between the first polarization image formed first and the second polarization image formed later, and then the to-be-verified depth image is compared with a base library depth image, so as to perform anti-counterfeiting identification. The base library depth image is formed by the code value difference of the same pixel position between the two base polarization images formed in the aforementioned registration stage for the correct face.

[0138] Optionally, the aforementioned face recognition method can be implemented based on a specific electronic device, such as an electronic device at least including a device main body and an image acquisition device, and the image acquisition device at least includes the aforementioned first light source, the second light source, the polarization device, and the image sensor with the photosensitive unit array 410, wherein the polarization directions of the polarization lights emitted by the first light source and the second light source are perpendicular to each other (which can be understood with reference to the foregoing related description), and the polarization direction of the polarization device is perpendicular to the polarization direction of the polarization light emitted by the first light source.

[0139] Therefore, S30 performs face recognition according to the first polarization image and the second polarization image, and obtains a face recognition result, and the face recognition includes face matching and / or anti-counterfeiting identification, which includes:

[0140] S31: Two-dimensional face matching verification is performed according to the first polarization image, and a two-dimensional face matching result is obtained.

[0141] S32: If the two-dimensional face matching result is not passed, the face recognition fails; if the two-dimensional face matching result is passed, anti-counterfeiting identification is performed according to the first polarization image and the second polarization image, and an anti-counterfeiting identification result is obtained.

[0142] If the anti-counterfeiting result is a real face, the face recognition succeeds; if the anti-counterfeiting result is a counterfeit, the face recognition fails. S31 and S32 can be executed after S20, or S31 can be executed after S10, if the two-dimensional face matching result is passed, S20 and S32 are executed again; if the two-dimensional face matching result is not passed, S20 is not executed again.

[0143] The first polarization image is obtained by using the first light source, the polarization device and the array of light sensing units. At this time, the first polarization image contains the least information because the polarization direction of the first light source is perpendicular to the polarization direction of the polarization device. The second polarization image is obtained by using the second light source, the polarization device and the array of light sensing units. At this time, the second polarization image contains the most information because the polarization direction of the second light source is the same as the polarization direction of the polarization device. The information difference between the two polarization images is the largest, which is beneficial to the identification of the target object.

[0144] Thus, the image recognition, i.e., two-dimensional face matching verification, can be performed by using the first polarization image and the base image, and the two-dimensional face matching result is obtained. The polarization direction of the first light source is perpendicular to the polarization direction of the polarization device, i.e., the polarization direction of the light emitting end is perpendicular to the polarization direction of the light receiving end, which can reduce the light spot problem caused by the reflection of the attack material (i.e., the fake object) or the face to the greatest extent, and can ensure the clarity of the first polarization image, thereby facilitating the face matching verification.

[0145] As described above, the two-dimensional face matching result includes two results of pass and fail. The subsequent anti-counterfeiting identification can perform different actions according to the two-dimensional face matching result. For example, if the two-dimensional face matching result is fail, the face recognition directly fails, and the anti-counterfeiting identification is not performed. If the two-dimensional face matching result is pass, the anti-counterfeiting identification is performed according to the first polarization image and the second polarization image, and the anti-counterfeiting identification result is obtained.

[0146] Alternatively, the face matching and the anti-counterfeiting identification can also be performed simultaneously. For example, S30 can specifically be: forming a depth image (to-be-verified depth image) according to the code value difference of the first polarization image and the second polarization image at the same pixel position, performing face recognition according to the depth image, and obtaining a face recognition result.

[0147] Firstly, when the base image is recorded, the base depth image can be formed by the code value difference of the two base polarization images formed by the correct face in the recording stage.

[0148] Then, when the face recognition is performed, the to-be-verified depth image and the base depth image can be compared, so that the face matching and the anti-counterfeiting identification can be performed simultaneously.

[0149] Of course, the face recognition method described above can be applied to the electronic device described above.

[0150] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A group of light sources, characterized in that The light source set comprises at least two light sources, each of the light sources is configured to emit polarized light with a degree of polarization unequal to 0, and the light source set emits polarized light with at least two polarization directions, and the polarized light with the at least two polarization directions sequentially enters an image sensor after being reflected by a target object and carrying polarization information corresponding to a profile of the target object.

2. The light source set according to claim 1, wherein At least one of the light sources satisfies the following condition: The light source comprises a light emitting element configured to emit the polarized light emitted by the light source. Or, the light source comprises a light emitting element and a polarizing element, and the light emitting element emits light which is modulated by the polarizing element to form the polarized light emitted by the light source.

3. The light source set of claim 2, wherein The light emitting element is a laser, and a diffusion element is further arranged on a light emitting side of the laser, and the diffusion element is configured to expand a light emitting angle of the laser.

4. The light source set of claim 3, wherein When the light source comprises the light emitting element and the polarizing element, and the light emitting element is the laser, the polarizing element is located between the laser and the diffusion element.

5. The light source set according to claim 3, wherein When the light source comprises the light emitting element and the polarizing element, and the light emitting element is the laser, the light source is a packaged light source, the packaged light source further comprises a packaging substrate and a support structure, the laser is fixed to the packaging substrate, the support structure is fixed to the packaging substrate and located beside the laser, the polarizing element and the diffusion element are separate components, and the polarizing element and the diffusion element are respectively fixed to the support structure, wherein the polarizing element is located between the laser and the diffusion element, or the diffusion element is located between the laser and the polarizing element.

6. The light source set of claim 3, wherein When the light source comprises the light emitting element and the polarizing element, and the light emitting element is the laser, the light source is a packaged light source, the packaged light source further comprises a substrate, a packaging substrate and a support structure, the laser is fixed to the packaging substrate, the support structure is fixed to the packaging substrate and located beside the laser, the polarizing element is a polarizing unit on one side surface of the substrate, the diffusion element is a diffusion unit on the other side surface of the substrate, and the substrate is fixed to the support structure, wherein the polarizing unit is located between the laser and the diffusion unit, or the diffusion unit is located between the laser and the polarizing unit.

7. The set of light sources according to any one of the claims 1 to 6, characterized in that, The degree of polarization of the polarized light emitted by at least one of the light sources is greater than 0.

1.

8. The set of light sources according to any one of claims 1 to 6, characterized in that The maximum polarization directions of the polarized light emitted by at least two of the light sources are different.

9. The set of light sources according to any one of claims 1 to 6, characterized in that The light emitting wave bands of at least two of the light sources are the same.

10. The set of light sources according to any one of claims 1 to 6, characterized in that The light emitting wave band of at least one of the light sources is 940 nm.

11. The set of light sources according to any one of claims 1 to 6, characterized in that The at least two light sources are distributed on the same side or opposite sides of the image sensor.

12. The set of light sources according to any one of claims 1 to 6, characterized in that Among the polarized light emitted by the light source set, the polarization directions of at least two of the polarized light form a first included angle, or the polarization directions of any two of the polarized light form a first included angle, and the first included angle ranges from 45° to 135°.

13. The light source set of claim 12, wherein The first included angle ranges from 45° to 90° and / or from 90° to 135°.

14. An image receiver, characterized by The image sensor comprises an array of light sensing units, and a polarizing device is located on the light receiving side of the array of light sensing units, a polarization direction of the polarizing device forms a second included angle less than or equal to a target angle with one polarization direction of polarized light emitted by a light source group, the light source group comprises at least two light sources, each of the light sources is used to emit polarized light with a polarization degree not equal to 0, and the light source group emits polarized light with at least two polarization directions, and the polarized light with at least two polarization directions sequentially enters the image sensor after being reflected by a target object and carrying polarization information corresponding to a profile of the target object.

15. The image receiver of claim 14, wherein, The target angle is 5°, 10°, 15°, 20°, 25° or 30°.

16. The image receiver according to claim 14 or 15, characterized in that The light source group comprises two light sources, and the polarization directions of the polarized light emitted by the two light sources are perpendicular to each other.

17. The image receiver of claim 14 or 15, wherein The polarization direction of the polarizing device is the same as one polarization direction of the polarized light emitted by the light source group. Among the polarized light emitted by the light source group, at least two polarization directions of the polarized light form a first included angle, or, any two polarization directions of the polarized light form a first included angle, and the first included angle ranges from [45°, 90°) and / or (90°, 135°].

18. The image receiver of claim 14 or 15, wherein, The image receiver further comprises a narrow bandpass filter, and the narrow bandpass filter is located on the light receiving side of the array of light sensing units, and a bandpass wavelength range of the narrow bandpass filter covers an emission wavelength range of the light source group.

19. The image receiver of claim 18, wherein, When the emission wavelength range of the light source group is 940 nm, the bandpass wavelength range of the narrow bandpass filter is 940 nm±10 nm.

20. The image receiver of claim 14 or 15, wherein, The polarizing device is separate from the image sensor, or the polarizing device is integrated inside the image sensor.

21. An image acquisition device, characterized in that The image receiver comprises an image sensor and a polarizing device, the image sensor comprises an array of light sensing units, the polarizing device is located on the light receiving side of the array of light sensing units, and a polarization direction of the polarizing device forms a second included angle less than or equal to a target angle with one polarization direction of polarized light emitted by a light source group, the light source group comprises at least two light sources, each of the light sources is used to emit polarized light with a polarization degree not equal to 0, and the light source group emits polarized light with at least two polarization directions, and the polarized light with at least two polarization directions sequentially enters the image sensor after being reflected by a target object and carrying polarization information corresponding to a profile of the target object.

22. An electronic device, comprising: The image acquisition device is arranged on the device body.

Images