Optical acquisition device and electronic equipment

Abstract

The utility model provides an optical acquisition device and electronic equipment, and relates to the technical field of biological recognition, a display screen can emit circularly polarized light for display in a visible light wave band, and an infrared light source is arranged in the optical acquisition device, so that light which can be received by a photoelectric sensor and carries biological characteristic information can be effectively increased; in this way, the biological characteristic information of the target object can be collected more comprehensively, and the recognition accuracy can be improved conveniently. Or a filter film is arranged in the optical acquisition device, and the cut-off wave band of the filter film comprises the wavelength of the circularly polarized light, so that the light which is received by the photoelectric sensor and does not carry the biological characteristic information is reduced through the filter film, and the signal-to-noise ratio is improved.

Description

Technical Field

[0001] The present application relates to the technical field of biometric information recognition, and in particular, to an optical acquisition device and an electronic device. Background Art

[0002] With the development of science and technology, electronic devices with display functions have penetrated into every corner of daily life. In order to optimize the safety and convenience of user use, fingerprint modules are gradually integrated under the display panels of electronic devices. They receive, record and analyze light carrying fingerprint features to confirm and identify the target object to which the fingerprint features belong. Various functions have been derived from this, which not only enriches the user experience, but also increases the time users use electronic devices.

[0003] After using electronic devices for a long time, it is easy for users' eyes to feel uncomfortable, so the industry has introduced circularly polarized eye protection screens to alleviate this problem. However, the principle of circularly polarized eye protection screens is to use a circular polarizer to convert the linearly polarized light originally emitted from the screen into circularly polarized light. Since circularly polarized light is closer to natural light, it can protect the eyes after being received by the user's eyes. However, during the research and development process, it was found that due to the half-wave loss of circularly polarized light after being reflected by the finger, its polarization state changes, resulting in the circularly polarized light being difficult to pass through the circular polarizer after being reflected by the finger and being received by the fingerprint module under the screen, which in turn leads to poor fingerprint recognition effect. Utility Model Content

[0004] The purpose of the present application is to provide an optical collection device and an electronic device to address the deficiencies in the above-mentioned prior art.

[0005] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0006] According to one aspect of an embodiment of the present application, an optical collection device is provided, which is configured under a display screen. The display screen can emit circularly polarized light for display in the visible light band. The optical collection device includes an infrared light source and a photoelectric sensor. A first light beam emitted by the infrared light source is reflected by a target object above the display screen, passes through the display screen, and is incident on the photoelectric sensor.

[0007] Optionally, a filter film is arranged between the photoelectric sensor and the display screen, and the passband of the filter film includes the light-emitting band of the infrared light source.

[0008] Optionally, the bandpass band of the filter film includes λ1, and the luminous band of the infrared light source is λ 10 ,λ1=λ 10 ±10nm.

[0009] Optionally, the bandpass band of the filter film also includes a visible light band.

[0010] Optionally, the light emission wavelength range of the infrared light source is from 780 nm to 1000 nm.

[0011] Optionally, the optical collection device includes a first circuit board, and the infrared light source and the photoelectric sensor are both arranged on the first circuit board;

[0012] Alternatively, the optical collection device includes a second circuit board and a third circuit board that are spaced apart from each other, the infrared light source is disposed on the second circuit board, and the photoelectric sensor is disposed on the third circuit board.

[0013] Optionally, the infrared light source is located beside the photoelectric sensor.

[0014] Optionally, a filter film is arranged between the photoelectric sensor and the display screen, and the cutoff band of the filter film includes the wavelength of circularly polarized light.

[0015] Optionally, the cutoff band of the filter film includes at least one of 500nm, 550nm, and 590nm.

[0016] Optionally, a shading structure is further provided on the receiving side of the photoelectric sensor, the shading structure at least being used to prevent the second light emitted by the infrared light source from entering the photoelectric sensor, wherein the light emitted by the infrared light source is reflected by the lower surface of the display screen to form the second light.

[0017] Optionally, in the recording mode, the infrared light source is turned on and the collection area of ​​the display screen is turned off, or the infrared light source and the collection area of ​​the display screen are turned on at the same time.

[0018] Optionally, in the identification mode, the infrared light source is off and the collection area of ​​the display screen is on, or the infrared light source and the collection area of ​​the display screen are on at the same time, or the infrared light source is on and the collection area of ​​the display screen is off.

[0019] In another aspect of the embodiments of the present application, a fingerprint collection method is provided, the method comprising:

[0020] In the recording mode, the infrared light source is controlled to light up and the fingerprint collection area of ​​the display screen is turned off, or the infrared light source and the fingerprint collection area of ​​the display screen are controlled to light up at the same time, and the fingerprint base database image is collected using any of the above optical collection devices;

[0021] In the recognition mode, the infrared light source is controlled to be off and the fingerprint collection area of ​​the display screen is lit, or the infrared light source and the fingerprint collection area of ​​the display screen are controlled to be lit at the same time, or the infrared light source is controlled to be lit and the fingerprint collection area of ​​the display screen is off, and the fingerprint image to be recognized is collected using any of the above optical collection devices.

[0022] According to another aspect of an embodiment of the present application, an optical collection device is provided, which is used to be configured under a display screen, and the display screen can emit circularly polarized light for display in the visible light band. The optical collection device includes a photoelectric sensor and a filter film, and the filter film is located between the photoelectric sensor and the display screen. The cutoff band of the filter film includes the wavelength of the circularly polarized light.

[0023] Optionally, the cutoff band of the filter film includes at least one of 500nm, 550nm, and 590nm.

[0024] According to another aspect of the embodiments of the present application, an electronic device is provided, including a display screen and any one of the above-mentioned optical collection devices, wherein the display screen includes a light-emitting module and a circular polarizer, the circular polarizer is located above the light-emitting module, and the optical collection device is located below the light-emitting module.

[0025] The beneficial effects of this application include:

[0026] The present application provides an optical acquisition device and an electronic device, wherein the optical acquisition device is configured under a display screen, and the display screen can emit circularly polarized light for display in the visible light band. The optical acquisition device includes an infrared light source and a photoelectric sensor. After the first light emitted by the infrared light source is incident on the display screen, the display screen does not modulate the polarization state of the first light, so the first light can be smoothly emitted from the display screen and then reach the target object. Subsequently, the first light is reflected by the target object, thereby carrying the biometric information of the target object back to the display screen. The display screen also does not modulate the polarization state of the first light, so the first light will not be blocked by the display screen, but can smoothly pass through the display screen and emit from the bottom of the display screen, and then be received by the photoelectric sensor, effectively increasing the light carrying biometric information that can be received by the photoelectric sensor, so that the biometric information of the target object can be more comprehensively collected, which is convenient for improving the accuracy of recognition.

[0027] The present application provides an optical acquisition device and an electronic device. The optical acquisition device is used to be configured under a display screen. The display screen can emit circularly polarized light for display in the visible light band. The optical acquisition device includes a photoelectric sensor and a filter film. The filter film is located between the photoelectric sensor and the display screen. The cutoff band of the filter film includes the wavelength of the circularly polarized light. Among the visible light emitted by the display screen, the light modulated into circularly polarized light and emitted from the display screen will produce a change in polarization state due to the incident target object, so it is difficult to pass through the display screen and be received by the photoelectric sensor. However, the light consistent with the circularly polarized light band in the visible light also includes light that does not carry biometric information. This part of the light may be reflected before it is emitted from the display screen and then propagates toward the bottom of the display screen. The cutoff band of the filter film blocks this part of the light that does not carry the biometric information, thereby reducing the light that does not carry the biometric information received by the photoelectric sensor, thereby improving the signal-to-noise ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A schematic diagram of the structure of a circular polarized eye protection screen provided by the prior art;

[0030] Figure 2 One of the structural schematic diagrams of an electronic device provided in an embodiment of the present application;

[0031] Figure 3 A second structural diagram of an electronic device provided in an embodiment of the present application;

[0032] Figure 4 A third structural diagram of an electronic device provided in an embodiment of the present application;

[0033] Figure 5 A fourth structural diagram of an electronic device provided in an embodiment of the present application;

[0034] Figure 6 A fifth structural diagram of an electronic device provided in an embodiment of the present application;

[0035] Figure 7 The sixth structural diagram of an electronic device provided in an embodiment of the present application.

[0036] Icons: 14-finger; 100-display screen; 101-display light; 102-non-circularly polarized light; 103-invalid light; 110-light-emitting module; 120-circular polarizer; 121-second 1 / 4 wave plate; 122-first linear polarizer; 123-first 1 / 4 wave plate; 210-infrared light source; 211-first light; 212-second light; 220-photoelectric sensor; 230-filter film; 240-shading structure; 250-lens assembly. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. It should be noted that, in the absence of conflict, the various features in the embodiments of the present application can be combined with each other, and the combined embodiments are still within the scope of protection of the present application.

[0038] In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the application is usually placed when in use. They are only for the convenience of describing this application and simplifying the description, and therefore cannot be understood as limiting this application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0039] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] Figure 1 A schematic diagram of the structure of a circular polarized eye protection screen provided by the prior art. Figure 1 , the circular polarized eye protection screen includes a light emitting module 11, a linear polarizer 12 and a quarter wave plate 13 in sequence, and the absolute value of the angle between the polarization direction of the linear polarizer 12 and the fast axis of the quarter wave plate 13 is 45 degrees. Among them, when the circular polarized eye protection screen displays the picture, the natural light emitted by the light emitting module 11 is emitted through the linear polarizer 12 and the quarter wave plate 13 in sequence and received by the human eye. In this process, the natural light becomes linear polarized light after passing through the linear polarizer 12, and the linear polarized light becomes circular polarized light after passing through the quarter wave plate 13. Since circular polarized light is closer to natural light than linear polarized light, it can alleviate the discomfort of the user's eyes during use.

[0041] Figure 1 Although the circularly polarized eye protection screen shown can alleviate the discomfort of the user's eyes during use, it will block the circularly polarized light reflected by the finger 14, thereby affecting the reception of this part of light by the fingerprint module under the screen. The main reason is that a part of the circularly polarized light emitted by the 1 / 4 wave plate 13 will be incident on the finger 14. After this part of the circularly polarized light is reflected by the finger 14, a half-wave loss will occur, thereby causing the rotation direction of this part of the circularly polarized light to change, such as Figure 1In the figure, the circularly polarized light emitted from the 1 / 4 wave plate 13 is right-handed circularly polarized light before entering the finger 14. After being reflected by the finger 14, half-wave loss occurs, and the reflected light becomes left-handed circularly polarized light. The left-handed circularly polarized light becomes linearly polarized light after passing through the 1 / 4 wave plate 13. However, the polarization direction of the linear polarized light at this time is perpendicular to the polarization direction of the linear polarizer 12. Therefore, the linear polarized light is blocked by the linear polarizer 12, resulting in the circularly polarized light being difficult to be received by the fingerprint module under the screen after being reflected by the finger 14, which in turn leads to poor fingerprint recognition effect.

[0042] Based on the problems existing in the circular polarized eye protection screen, the present application provides an optical collection device that can improve the above problems. For ease of understanding, it is applied to electronic devices for demonstration. Figure 2 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 2 , showing an optical collection device and a display screen 100, and the optical collection device is located below the display screen 100. Specifically, the display screen 100 has a display side and a non-display side opposite to the display side, corresponding to Figure 2 In the embodiment, the upper side of the display screen 100 can be used as the display side, and the lower side of the display screen 100 can be used as the non-display side. The optical collection device is located on the non-display side of the display screen 100 to realize the function of collecting information under the screen.

[0043] The display screen 100 displays images on the display side by emitting light. To facilitate human eye perception, the light emission band of the display screen 100 is generally in the visible light band. When the display screen 100 displays images, in order to reduce the discomfort of users during long-term use, it is necessary to make the light emitted by the display screen 100 include circularly polarized light. Therefore, a polarization structure (such as a polarization structure shown in the subsequent embodiments: circular polarizer 120) that can convert at least part of the visible light emitted by the display screen 100 into circularly polarized light should be provided in the display screen 100. Figure 2 In the embodiment, the display screen 100 emits a display light 101 in the visible light band, and the display light 101 is emitted from the display surface in the form of circularly polarized light after being converted by the polarization structure.

[0044] Please refer to Figure 2 The optical collection device includes an infrared light source 210 and a photoelectric sensor 220 . The infrared light source 210 and the photoelectric sensor 220 are both located below the display screen 100 , that is, located on the side of the non-display surface of the display screen 100 .

[0045] The infrared light source 210 can emit a first light ray 211 in an infrared band (including near infrared, mid-infrared and / or far infrared bands). Specifically, the positional relationship between the light emitting direction of the infrared light source 210 and the display screen 100 can be at least in the following forms: In one possible arrangement, the light emitting direction of the infrared light source 210 is toward the display screen 100, so that the first light ray 211 propagates toward the display screen 100 after being emitted from the infrared light source 210 and then enters the display screen 100; In another possible arrangement, the light emitting direction of the infrared light source 210 is not toward the display screen 100, but a light guiding structure is arranged on the light emitting side of the infrared light source 210, and the first light ray 211 propagates toward the display screen 100 after being emitted from the infrared light source 210 and guided by the light guiding structure and enters the display screen 100. It should be understood that the light emitting direction of the infrared light source 210 refers to the propagation direction of the central light in the light beam emitted by the infrared light source 210.

[0046] For the purpose of eye protection, the polarization structure in the display screen 100 needs to modulate at least part of the visible light emitted by the display screen 100 into circularly polarized light, so the modulation band of the polarization structure (including only the band modulated into circularly polarized light) is usually in the visible light band. Based on this, after the first light 211 in the infrared band is incident on the display screen 100, the polarization structure does not modulate the polarization state of the first light 211, so the first light 211 can smoothly pass through the polarization structure and be emitted from the display screen 100, and then reach the target object. Subsequently, the first light 211 is reflected by the target object, thereby carrying the biometric information of the target object back to the display screen 100. The polarization structure also does not modulate the polarization state of the first light 211, so the first light 211 is not blocked by the polarization structure, but can smoothly pass through the display screen 100 and be emitted from the bottom of the display screen 100, and then be received by the photoelectric sensor 220, so as to generate a captured image through the photoelectric conversion of the photoelectric sensor 220 and in combination with data processing, etc. In this way, the light carrying the biometric information that can be received by the photoelectric sensor 220 is effectively increased, thereby improving the imaging quality. In other words, it is possible to more comprehensively collect the biometric information of the target object, thereby facilitating the improvement of the recognition accuracy.

[0047] The target objects in the present application include but are not limited to fingers 14, palms, human eyes, human faces, etc. Correspondingly, the biometric information may be fingerprint feature information, palm print feature information, finger vein feature information, iris feature information, human face feature information, etc. depending on the target object.

[0048] For ease of understanding, the visible light emitted by the display screen 100 is described as follows: when the modulation band (including only the band modulated into circularly polarized light) of the polarization structure in the display screen 100 does not completely cover the light emission band of the display screen 100, among the visible light emitted by the display screen 100, only the light within the modulation band will be modulated by the polarization structure into circularly polarized light for emission, while the light outside the modulation band will not be modulated by the polarization structure or will be modulated by the polarization structure into non-circularly polarized light 102 (e.g., elliptically polarized light, linearly polarized light, etc.). Therefore, at least part of the light outside the modulation band can pass through the display screen 100 to reach the target object, and after being reflected by the target object, it carries the biometric information of the target object and passes through the display screen 100 to be received by the photoelectric sensor 220 below the display screen 100. For ease of description, among the visible light emitted by the display screen 100, the light outside the modulation band is called non-circularly polarized light 102.

[0049] For example, the modulation band usually covers the band that the human eye is more sensitive to. For example, when the light-emitting band of the display screen 100 includes red, green and blue bands, the modulation band generally covers the green light band that the human eye is more sensitive to. Therefore, the green light band is usually modulated into circularly polarized light and emitted from the display screen 100. After being reflected by the target object and returning to the display screen 100, it will be blocked. However, part of the red and blue band light is outside the modulation band, so it may be modulated into elliptically polarized light or linearly polarized light and emitted from the display screen 100. After being reflected by the target object, this part of the light can carry the target's biometric information through the display screen 100 and be received by the photoelectric sensor 220 under the display screen 100.

[0050] When the biometric information recognition function of an electronic device is used for the first time, it is usually divided into two stages. The first stage is: in this stage, the electronic device usually works in the input mode, and the biometric information of the correct target object is first input (for the convenience of description, it is referred to as the input stage in the following). The biometric information is also the collected biological image. In this stage, the input biological image is directly stored as a base image or stored as a base image after splicing and other processing. The second stage is: in this stage, the electronic device usually works in the recognition mode, obtains the biometric information (that is, the biological image) of the target to be identified, and compares and analyzes it with the base image stored in the input stage to verify whether the target to be identified is the correct target (also for the convenience of description, it is referred to as the recognition stage in the following), that is, whether the target to be identified and the correct target are the same person or the same finger of the same person, etc.; the second stage can also include: anti-counterfeiting recognition, that is, judging whether the target to be identified is a counterfeit such as a photo, video, fingerprint silicone mold, etc. through the biometric information (biological image) of the target to be identified. Based on this, in order to better understand the technical solution of the present application, the following will introduce the input stage and the recognition stage respectively:

[0051] Entry stage

[0052] In order to ensure the normal use of the functions in the subsequent recognition stage, the correct biometric information of the target object needs to be entered when it is used for the first time. During the recording process, in order to improve the accuracy of subsequent recognition, it is necessary to light up the infrared light source 210 during the recording stage, so that the polarization modulation of the display screen during recording has no effect on the infrared light emitted by the infrared light source, so the image quality obtained is good, especially the center quality of the image is high, which increases the area of ​​the recorded base image. The recording methods include:

[0053] One of the recording methods: During the recording process, the collection area of ​​the display screen is turned off (i.e., no light is emitted), and the infrared light source is turned on, so that the infrared light source 210 emits a first light ray 211, and the first light ray 211 passes through the display screen 100 to reach the correct target object, and then carries the biometric information of the correct target object back to the display screen 100 and passes through the display screen 100 and is then received by the photoelectric sensor 220, thereby obtaining and storing the biometric information of the correct target object.

[0054] The second way of recording: during the recording process, the infrared light source is turned on, so that the infrared light source 210 emits the first light 211, and the display screen 100 also emits visible light (usually only the collection area of ​​the display screen 100 is turned on, so the visible light emitted by the display screen comes from the collection area of ​​the display screen 100). In this way, for the first light 211, after being emitted from the infrared light source 210, the first light 211 passes through the display screen 100 to reach the correct target object, and then carries the biometric information of the correct target object back to the display screen 100 and passes through the display screen 100 to be received by the photoelectric sensor 220. For the visible light emitted by the display screen 100, part of the visible light (non-circularly polarized light 102) that is not modulated into circularly polarized light will pass through the display screen 100 to reach the correct target object, and then carries the biometric information of the correct target object back to the display screen 100 and passes through the display screen 100 to be received by the photoelectric sensor 220. Thus, the biometric information of the correct target object is obtained and stored through the light emitted by the infrared light source 210 and the display screen 100.

[0055] Identification Phase

[0056] After completing the biometric information entry, when the target object to be identified contacts the display screen 100, it is necessary to obtain the biometric information (i.e., biometric image) of the target object to be identified through an optical acquisition device, and compare and analyze it with the base library image stored in the entry stage to verify whether the target object to be identified is the correct target object and determine whether it is a counterfeit, thereby performing anti-counterfeiting identification. The identification methods include:

[0057] One of the identification methods: During the identification process, the infrared light source 210 is turned off (no light is emitted), and the display screen 100 emits visible light (usually only the collection area of ​​the display screen 100 is illuminated, so the visible light emitted by the display screen comes from the collection area of ​​the display screen 100), and part of the visible light that is not modulated into circularly polarized light (non-circularly polarized light 102) will pass through the display screen 100 to reach the target object to be identified, and then carry the biometric information of the target object to be identified back to the display screen 100 and pass through the display screen 100 to be received by the photoelectric sensor 220. Finally, the biometric information of the target object to be identified is compared and analyzed with the biometric information stored in the recording stage to verify whether the target object to be identified is the correct target object. Since more comprehensive biometric information is obtained in the recording stage, even if the infrared light source 210 is not turned on in the identification stage, the accuracy of identification can be improved.

[0058] The second identification method: During the identification process, the collection area of ​​the display screen is turned off (i.e., no light is emitted), and the infrared light source is turned on, so that the infrared light source 210 emits a first light ray 211, and the first light ray 211 passes through the display screen 100 to reach the target object to be identified, and then returns to the display screen 100 with the biometric information of the target object to be identified and passes through the display screen 100 to be received by the photoelectric sensor 220, and finally the biometric information of the target object to be identified is compared and analyzed with the biometric information stored in the input stage to verify whether the target object to be identified is the correct target object. Since more comprehensive biometric information is obtained in the input stage, and the infrared light source 210 is also turned on in the identification stage, the accuracy of identification can be effectively improved.

[0059] The third identification method: During the identification process, the infrared light source 210 emits a first light ray 211, and the display screen 100 also emits visible light (usually only the collection area of ​​the display screen 100 is lit, so the visible light emitted by the display screen comes from the collection area of ​​the display screen 100). In this way, for the first light ray 211, after being emitted from the infrared light source 210, the first light ray 211 passes through the display screen 100 to reach the target object to be identified, and then returns to the display screen 100 with the biometric information of the target object to be identified and passes through the display screen 100 to be received by the photoelectric sensor 220. For the visible light emitted by the display screen 100, part of the visible light (non-circularly polarized light 102) that is not modulated into circularly polarized light will pass through the display screen 100 to reach the target object to be identified, and then returns to the display screen 100 with the biometric information of the target object to be identified and passes through the display screen 100 to be received by the photoelectric sensor 220. Finally, the biometric information of the target object to be identified is compared and analyzed with the biometric information stored in the input stage to verify whether the target object to be identified is the correct target object. Since more comprehensive biometric information is obtained during the input stage, and the display screen 100 and the infrared light source 210 are also turned on during the recognition stage, the recognition accuracy can be improved.

[0060] By applying the aforementioned optical acquisition device to the display screen 100 with eye protection function, the recognition accuracy is improved. On this basis, in order to further improve the signal-to-noise ratio, the proportion of light (signal) carrying biometric information in the light received by the photoelectric sensor 220 is increased, and the proportion of light (noise) not carrying biometric information is reduced, such as Figure 3 As shown, a filter film 230 may be provided between the photoelectric sensor 220 and the display screen 100. The filter film 230 has a passband and a cutoff band, the passband refers to a high light transmittance band of the filter film 230, and the cutoff band refers to a low light transmittance band of the filter film 230, for example, the transmittance of the cutoff band is less than 2%.

[0061] Please continue to refer to Figure 3 The passband of the filter film 230 may include the emission band of the infrared light source 210. In this way, after the first light 211 carrying the biometric information is emitted from the bottom of the display screen 100, it can smoothly pass through the filter film 230 and then be received by the photoelectric sensor 220. Correspondingly, by reasonably setting the cutoff band, noise can be reduced. It should be understood that the emission band of the infrared light source 210 can be a range value or a point value.

[0062] Specifically, when setting the bandpass wavelength of the filter film 230, the bandpass wavelength of the filter film 230 may include λ1, and the wavelength of the infrared light source 210 may be λ 10 ,λ1=λ 10±10nm. For example, when the light-emitting band of the infrared light source 210 is 850nm, the bandpass band of the filter film 230 should include 850nm±10nm. For another example, when the light-emitting band of the infrared light source 210 is 940nm, the bandpass band of the filter film 230 should include 940nm±10nm.

[0063] In some possible implementations, the light emission wavelength range of the infrared light source 210 is from 780 nm to 1000 nm.

[0064] In some possible implementations, when the collection area of ​​the display screen 100 needs to be illuminated during the recording or recognition stage, the passband of the filter film 230 also includes the visible light band, so that when part of the visible light (non-circularly polarized light 102) that is not modulated into circularly polarized light needs to be used, the part of the visible light (non-circularly polarized light 102) that is not modulated into circularly polarized light can be emitted from the bottom of the display screen 100 and can also pass through the filter film 230 smoothly and then be received by the photoelectric sensor 220. For example, the passband of the filter film 230 also includes 400nm-630nm.

[0065] In some possible embodiments, when the bandpass band of the filter film 230 includes the visible light band and the light emitting band of the infrared light source 210, the filter film 230 is a dual-bandpass design. For example, the bandpass band of the filter film 230 includes 400nm-630nm and 850nm±10nm; for another example, the bandpass band of the filter film 230 includes 400nm-630nm and 940nm±10nm.

[0066] In some possible embodiments, the optical collection device includes a first circuit board, and the infrared light source 210 and the photoelectric sensor 220 are both arranged on the first circuit board. In other words, the infrared light source 210 and the photoelectric sensor 220 are integrated into a whole, so that the infrared light source 210 and the photoelectric sensor 220 can be led out through the first circuit board for final connection to the mainboard of the electronic device.

[0067] In some possible embodiments, the optical collection device includes a second circuit board and a third circuit board spaced apart from each other, the infrared light source 210 is arranged on the second circuit board, and the photoelectric sensor 220 is arranged on the third circuit board, that is, the infrared light source 210 and the photoelectric sensor 220 are arranged separately. At this time, the infrared light source 210 needs to be led out through the second circuit board, and the photoelectric sensor 220 needs to be led out through the third circuit board, so as to be finally connected to the mainboard of the electronic device.

[0068] In some possible implementations, the infrared light source 210 is located beside the photoelectric sensor 220. Specifically, when there are two or more infrared light sources 210, they may be evenly distributed around the photoelectric sensor 220.

[0069] In some possible implementations, such as Figure 3 As shown, a filter film 230 is arranged between the photoelectric sensor 220 and the display screen 100, and the cutoff band of the filter film 230 includes the wavelength of circularly polarized light. In other words, the cutoff band of the filter film 230 includes the modulation band of the polarization structure in the display screen 100 (only includes the band modulated into circularly polarized light).

[0070] Based on the above explanations and descriptions of the visible light emitted by the display screen 100, it can be known that among the visible light emitted by the display screen 100, although the light modulated into circularly polarized light will be reflected by the target object after being emitted from the display screen 100 and then return to the display screen 100 with biometric information, the light in the modulation band and carrying biometric information in the visible light is difficult to pass through the display screen 100 and be received by the photoelectric sensor 220 because the polarization structure in the display screen 100 will block it. However, the visible light also includes light in the modulation band but does not carry biometric information (referred to as invalid light 103 for ease of understanding). For example, part of the light in the modulation band of the visible light may be reflected and propagated toward the bottom of the display screen 100 before being emitted from the display screen 100 due to the shielding of the metal wires in the touch layer inside the display screen 100 during the propagation process. Because this part of the light does not carry biometric information, when it is received by the photoelectric sensor 220, it will cause more noise.

[0071] When the cutoff band of the filter film 230 includes the modulation band of the polarization structure in the display screen 100, the light in the visible light that is in the modulation band but does not carry biometric information will be blocked when it passes through the display screen 100 and reaches the filter film 230, thereby reducing the light (noise) that does not carry biometric information received by the photoelectric sensor 220, thereby improving the signal-to-noise ratio.

[0072] In some possible implementations, the cutoff wavelength band of the filter film 230 includes at least one of 500 nm, 550 nm, and 590 nm.

[0073] In some possible implementations, such as Figure 6 As shown, a lens assembly 250 is further disposed between the display screen 100 and the photoelectric sensor 220. Specifically, the lens assembly 250 may include at least one imaging lens. In addition, a lens barrel is further disposed around the imaging lens to fix the imaging lens.

[0074] In some possible implementations, such as Figure 4As shown, a light shielding structure 240 is also provided on the receiving side of the photoelectric sensor 220. The light shielding structure 240 has a light channel, and the side wall of the light channel is a light shielding wall, so that the first light 211 and / or part of the visible light that is not modulated into circularly polarized light (non-circularly polarized light 102) can enter through an opening at one end of the light channel and be emitted from an opening at the other end to be smoothly received by the photoelectric sensor 220. As shown in FIG. Figure 4 As shown, the light shielding structure 240 can be disposed above the photoelectric sensor 220, and the lower end opening of the light shielding structure 240 can be fixed to the bracket or the upper end of the lens barrel of the lens assembly 250. In addition, the inner diameter of the light channel from one end opening to the other end opening can be constant or change, and when the inner diameter of the light channel changes (gradually increases or gradually decreases), it can be a linear change or a nonlinear change.

[0075] like Figure 4 As shown, by providing the light shielding structure 240, it is possible to at least prevent the second light 212 emitted by the infrared light source 210 from entering the photoelectric sensor 220, wherein the light emitted by the infrared light source 210 is reflected by the lower surface of the display screen 100 to form the second light 212. And / or, the light shielding structure 240 can also prevent the light from directly entering the photoelectric sensor 220 without passing through the display screen 100.

[0076] In different embodiments, the filter film 230 may cover the surface of the photoelectric sensor 220. For example, the photoelectric sensor 220 includes a photoelectric sensor unit array. In this case, other optical film layers may be provided between the photoelectric sensor unit array and the filter film 230. For example, a light shielding layer with openings, a collimator layer, a transparent medium layer and / or a microlens layer may be provided between the photoelectric sensor unit array and the filter film 230. Of course, the filter film 230 may also be located inside the photoelectric sensor 220. For example, the filter film 230 may also be provided between any other optical film layers, or between the photoelectric sensor unit array and other optical film layers. In addition, the filter film 230 may also be provided between the display screen 100 and the lens assembly 250, between the lens assembly 250 and the photoelectric sensor 220, or inside the lens assembly 250. Of course, the filter film 230 may also be attached to the surface of the imaging lens in the lens assembly 250.

[0077] In different implementations, the filter film 230 may be a separate film layer structure, or the filter film 230 may be disposed on a substrate (eg, glass) to form a filter.

[0078] Another aspect of the present application provides an electronic device, such as Figure 6As shown, it includes a display screen 100 and any of the above-mentioned optical collection devices, the optical collection device includes an infrared light source 210, the display screen 100 includes a light-emitting module 110 and a circular polarizer 120, the circular polarizer 120 is located above the light-emitting module 110, and the optical collection device is located below the light-emitting module 110.

[0079] In some possible implementations, such as Figure 6 As shown, the circular polarizer 120 includes a first linear polarizer 122 and a first quarter wave plate 123 which are sequentially arranged along the light emitting direction of the light emitting module 110. Figure 6 As shown, after the light emitting module 110 emits light in the modulation band, the light is generally natural light, which is adjusted to linear polarized light after passing through the first linear polarizer 122 , and then adjusted to circular polarized light after passing through the first 1 / 4 wave plate 123 , and then emitted from the display screen 100 .

[0080] In some possible embodiments, the circular polarizer 120 also includes a 1 / 2 wave plate, which is located on the side of the first 1 / 4 wave plate 123 away from the first linear polarizer 122, and through the coordinated use of the 1 / 2 wave plate and the first 1 / 4 wave plate 123, a wide-band compensation effect can be achieved, that is, the modulation band (only including the band modulated into circularly polarized light) of the circular polarizer 120 in the display screen 100 is expanded to a range band.

[0081] In some possible implementations, such as Figure 6 As shown, the circular polarizer 120 further includes a second quarter wave plate 121, which is located between the first linear polarizer 122 and the light emitting module 110. The cooperation between the second quarter wave plate 121 and the first linear polarizer 122 can prevent ambient light from being reflected by the display screen 100 and entering the user's eyes.

[0082] In another aspect of the embodiments of the present application, a fingerprint collection method is provided, the method comprising:

[0083] S10: In the recording mode, the infrared light source is controlled to light up and the fingerprint collection area of ​​the display screen is turned off, or the infrared light source and the fingerprint collection area of ​​the display screen are controlled to light up at the same time, and the fingerprint base database image is collected using any of the above optical collection devices.

[0084] S20: In the recognition mode, the infrared light source is controlled to be turned off and the fingerprint collection area of ​​the display screen is turned on, or the infrared light source and the fingerprint collection area of ​​the display screen are controlled to be turned on at the same time, or the infrared light source is controlled to be turned on and the fingerprint collection area of ​​the display screen is turned off, and the fingerprint image to be recognized is collected using any of the above optical collection devices.

[0085] Combined with the above description of the biometric information recognition function of the first use of the electronic device, it can be known that there are generally two stages, namely the first stage and the second stage, and the first stage corresponds to the input mode and the second stage corresponds to the recognition mode.

[0086] By lighting up the infrared light source in the recording mode so that the infrared light it emits can participate in the process of acquiring biological images, it is possible to obtain images of better quality, especially the center of the image, which increases the area of ​​the recorded base image. On this basis, in the recording mode, the acquisition area of ​​the display screen can be selectively extinguished or lit.

[0087] In the recognition mode, one or all of the infrared light source and the display screen's collection area can be selectively lit up. This can improve the recognition accuracy based on the high-quality database images stored in the entry mode.

[0088] Another aspect of the present application provides an optical collection device, such as Figure 5 As shown, it is used to be arranged under the display screen 100, and the display screen 100 can emit circularly polarized light for display in the visible light band. The optical collection device includes a photoelectric sensor 220 and a filter film 230. The filter film 230 is located between the photoelectric sensor 220 and the display screen 100. The cutoff band of the filter film 230 includes the wavelength of the circularly polarized light. In other words, the cutoff band of the filter film 230 includes the modulation band of the polarization structure in the display screen 100 (including only the band modulated into circularly polarized light). In this embodiment, the optical collection device may not be provided with an infrared light source 210.

[0089] Based on the above explanations and descriptions of the visible light emitted by the display screen 100, it can be known that among the visible light emitted by the display screen 100, although the light modulated into circularly polarized light will be reflected by the target object after being emitted from the display screen 100 and then return to the display screen 100 with biometric information, the light in the modulation band and carrying biometric information in the visible light is difficult to pass through the display screen 100 and be received by the photoelectric sensor 220 because the polarization structure in the display screen 100 will block it. However, the visible light also includes light in the modulation band but does not carry biometric information (referred to as invalid light 103 for ease of understanding). For example, part of the light in the modulation band of the visible light may be reflected and propagated toward the bottom of the display screen 100 before being emitted from the display screen 100 due to the shielding of the metal wires in the touch layer inside the display screen 100 during the propagation process. Because this part of the light does not carry biometric information, when it is received by the photoelectric sensor 220, it will cause more noise.

[0090] When the cutoff band of the filter film 230 includes the modulation band of the polarization structure in the display screen 100, the light in the visible light that is in the modulation band but does not carry biometric information will be blocked when it passes through the display screen 100 and reaches the filter film 230, thereby reducing the light (noise) that does not carry biometric information received by the photoelectric sensor 220, thereby improving the signal-to-noise ratio.

[0091] In some possible implementations, the cutoff wavelength band of the filter film 230 includes at least one of 500 nm, 550 nm, and 590 nm.

[0092] In some possible implementations, according to the above description, the optical collection device may selectively have a light shielding structure 240, a lens assembly 250, etc. When setting the filter film 230, it may also be reasonably set by referring to the above-mentioned various setting methods of the filter film 230.

[0093] In some possible implementations, the display screen 100 may be an organic light emitting diode (OLED) display screen 100 or a liquid crystal display screen 100 (LCD), etc., which is not limited in the present application.

[0094] Another aspect of the present application provides an electronic device, such as Figure 7 As shown, it includes a display screen 100 and any of the above-mentioned optical collection devices, the optical collection device does not include the infrared light source 210, the display screen 100 includes a light-emitting module 110 and a circular polarizer 120, the circular polarizer 120 is located above the light-emitting module 110, and the optical collection device is located below the light-emitting module 110.

[0095] In some possible implementations, such as Figure 7 As shown, the circular polarizer 120 includes a first linear polarizer 122 and a first quarter wave plate 123 which are sequentially arranged along the light emitting direction of the light emitting module 110. Figure 7 As shown, after the light emitting module 110 emits light in the modulation band, the light is generally natural light, which is adjusted to linear polarized light after passing through the first linear polarizer 122 , and then adjusted to circular polarized light after passing through the first 1 / 4 wave plate 123 , and then emitted from the display screen 100 .

[0096] In some possible embodiments, the circular polarizer 120 also includes a 1 / 2 wave plate, which is located on the side of the first 1 / 4 wave plate 123 away from the first linear polarizer 122, and through the coordinated use of the 1 / 2 wave plate and the first 1 / 4 wave plate 123, a wide-band compensation effect can be achieved, that is, the modulation band (only including the band modulated into circularly polarized light) of the circular polarizer 120 in the display screen 100 is expanded to a range band.

[0097] In some possible implementations, such as Figure 7 As shown, the circular polarizer 120 further includes a second quarter wave plate 121, which is located between the first linear polarizer 122 and the light emitting module 110. The cooperation between the second quarter wave plate 121 and the first linear polarizer 122 can prevent ambient light from being reflected by the display screen 100 and entering the user's eyes.

[0098] In some possible implementations, the display screen 100 may be an organic light emitting diode (OLED) display screen 100 or a liquid crystal display screen 100 (LCD), etc., which is not limited in the present application.

[0099] A fingerprint recognition method can be preset in the electronic device provided in the present application, and the fingerprint recognition method generally includes the steps of acquiring, preprocessing, feature extraction, feature matching, etc. of the fingerprint image. Some or all of the above steps can be implemented by a traditional computer vision (CV) algorithm, or by a deep learning algorithm based on artificial intelligence (AI). Fingerprint recognition technology can be applied to portable or mobile terminals such as smart phones, tablet computers, and gaming devices, as well as other electronic devices such as smart door locks, cars, and bank ATMs, for fingerprint unlocking, fingerprint payment, fingerprint attendance, identity authentication, etc.

[0100] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. 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. An optical collection device, characterized in that: It is used to be configured under a display screen, and the display screen can emit circularly polarized light for display in the visible light band. The optical collection device includes an infrared light source and a photoelectric sensor. The first light emitted by the infrared light source is reflected by a target object above the display screen, passes through the display screen, and is incident on the photoelectric sensor.

2. The optical collection device according to claim 1, characterized in that: A filter film is arranged between the photoelectric sensor and the display screen, and the bandpass band of the filter film includes the light-emitting band of the infrared light source.

3. The optical collection device according to claim 2, characterized in that: The bandpass wavelength of the filter film includes λ1, and the emission wavelength of the infrared light source is λ 10 ,λ1=λ 10 ±10nm.

4. The optical collection device according to claim 2 or 3, characterized in that: The bandpass band of the filter film also includes a visible light band.

5. The optical collection device according to any one of claims 1 to 3, characterized in that: The light emission wavelength range of the infrared light source is from 780nm to 1000nm.

6. The optical collection device according to any one of claims 1 to 3, characterized in that: The optical collection device comprises a first circuit board, and the infrared light source and the photoelectric sensor are both arranged on the first circuit board; Alternatively, the optical collection device comprises a second circuit board and a third circuit board which are spaced apart from each other, the infrared light source is arranged on the second circuit board, and the photoelectric sensor is arranged on the third circuit board.

7. The optical collection device according to claim 6, characterized in that: The infrared light source is located beside the photoelectric sensor.

8. The optical collection device according to any one of claims 1 to 3, characterized in that: A filter film is arranged between the photoelectric sensor and the display screen, and a cutoff wavelength band of the filter film includes the wavelength of the circularly polarized light.

9. The optical collection device according to claim 8, characterized in that: The cut-off wavelength band of the filter film includes at least one of 500nm, 550nm, and 590nm.

10. The optical collection device according to any one of claims 1 to 3, characterized in that: A shading structure is also provided on the receiving side of the photoelectric sensor, and the shading structure is at least used to prevent the second light emitted by the infrared light source from entering the photoelectric sensor, wherein the light emitted by the infrared light source is reflected by the lower surface of the display screen to form the second light.

11. The optical collection device according to any one of claims 1 to 3, characterized in that: In the recording mode, the infrared light source is on and the collection area of ​​the display screen is off, or the infrared light source and the collection area of ​​the display screen are on at the same time; In the identification mode, the infrared light source is off and the collection area of ​​the display screen is on, or the infrared light source and the collection area of ​​the display screen are on at the same time, or the infrared light source is on and the collection area of ​​the display screen is off.

12. An optical collection device, characterized in that: It is used to be configured under a display screen, and the display screen can emit circularly polarized light for display in the visible light band. The optical collection device includes a photoelectric sensor and a filter film, and the filter film is located between the photoelectric sensor and the display screen. The cutoff band of the filter film includes the wavelength of the circularly polarized light.

13. The optical collection device according to claim 12, characterized in that: The cut-off wavelength band of the filter film includes at least one of 500nm, 550nm, and 590nm.

14. An electronic device, characterized in that: It comprises a display screen and the optical collection device according to any one of claims 1 to 11 or claims 12 to 13, wherein the display screen comprises a light-emitting module and a circular polarizer, wherein the circular polarizer is located above the light-emitting module, and the optical collection device is located below the light-emitting module.

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