Fingerprint detection device and electronic device

Abstract

The present application provides a fingerprint detection device that can improve the recognition effect of fingerprint detection. The fingerprint detection device is used to be arranged below the display screen of an electronic device, and is characterized in that it includes: a microlens array, including a plurality of microlenses; at least two light-blocking layers, arranged below the microlens array, each of the at least two light-blocking layers including at least one first small hole corresponding to each microlens in the microlens array; a pixel unit array, arranged below the at least two light-blocking layers, wherein the bottom light-blocking layer of the at least two light-blocking layers is a metal layer, and the first small holes in the bottom light-blocking layer correspond one-to-one to the pixel units; a filter layer, arranged between the bottom light-blocking layer and the upper light-blocking layer of the bottom light-blocking layer; and a lateral light-blocking layer, arranged on the upper surface of the non-opening area of ​​the bottom light-blocking layer and located below the filter layer.

Description

Technical Field

[0001] The present application relates to the field of optical fingerprint technology, and more specifically, to a fingerprint detection device and an electronic device. Background Art

[0002] At present, under-screen optical fingerprint detection devices have been mass-produced in electronic products such as smartphones and have been well received by users. However, when the external ambient light is strong, this part of the light will become leakage light and enter the pixel unit of the fingerprint detection device. This part of the leakage light may cause the pixel unit to be overexposed, making it impossible to form an image.

[0003] Therefore, how to improve the recognition effect of the fingerprint detection device in strong light scenes and enhance the user experience is an issue that needs to be addressed urgently. Summary of the invention

[0004] The embodiments of the present application provide a fingerprint detection device and an electronic device, which can improve the quality of fingerprint imaging in strong light scenes and further improve the recognition effect of the fingerprint detection device.

[0005] In a first aspect, a fingerprint detection device is provided.

[0006] Used to be arranged under the display screen of an electronic device, characterized by comprising:

[0007] A microlens array comprising a plurality of microlenses;

[0008] At least two light-blocking layers are disposed below the microlens array, each of the at least two light-blocking layers comprising at least one first pinhole corresponding to each microlens in the microlens array;

[0009] A pixel unit array is arranged below the at least two light-blocking layers, the pixel unit array includes at least one pixel unit corresponding to each of the microlenses, the pixel unit is used to receive the light signal converged by the corresponding microlens and guided through the first small holes in the at least two light-blocking layers, wherein the bottom light-blocking layer in the at least two light-blocking layers is a metal layer, and the first small holes in the bottom light-blocking layer correspond to the pixel units one by one;

[0010] A light filter layer is arranged between the bottom light-blocking layer and a light-blocking layer above the bottom light-blocking layer;

[0011] A lateral light-blocking layer is arranged on the upper surface of the non-opening area of ​​the underlying light-blocking layer and is located below the filter layer. The height of the lateral light-blocking layer is greater than or equal to 90% of the distance between the underlying light-blocking layer and the filter layer. The lateral light-blocking layer includes at least one second small hole corresponding to each microlens, and the size of the second small hole is greater than the size of the first small hole in the underlying light-blocking layer.

[0012] In a possible implementation manner, each of the microlenses corresponds to a plurality of pixel units, and the second small holes correspond to the microlenses one-to-one, or the second small holes correspond to the pixel units one-to-one.

[0013] In a possible implementation manner, each of the microlenses corresponds to a pixel unit and a first small hole in each of the light blocking layers, and the second small holes correspond to the pixel units one by one.

[0014] In a possible implementation manner, the lateral light blocking layer is located on the lower surface of the filter layer.

[0015] In a possible implementation manner, the metal layer is an internal circuit layer of the pixel unit.

[0016] In a possible implementation manner, the lateral light-blocking layer is a film layer formed of black nickel or black chromium.

[0017] In a possible implementation, the lateral light-blocking layer is a film layer formed of metal, or a stacked structure formed of metal and oxide.

[0018] In a possible implementation manner, the top light-blocking layer of the at least two light-blocking layers includes a first small hole corresponding to each of the microlenses.

[0019] In a possible implementation, the fingerprint detection device further includes a first transparent medium layer located between the microlens array and a top light-blocking layer of the at least two light-blocking layers, and in a first small hole in the top light-blocking layer.

[0020] In a possible implementation, the at least two light-blocking layers are two light-blocking layers, and the fingerprint detection device further includes a second transparent medium layer, which is located between the filter layer and the top light-blocking layer of the at least two light-blocking layers.

[0021] In a possible implementation, the size of the second small hole is not smaller than the size of the first small hole in other light-blocking layers except the bottom light-blocking layer in the at least two light-blocking layers, and the size of the first small hole in the at least two light-blocking layers decreases from top to bottom.

[0022] In a possible implementation manner, except for the top light-blocking layer and the bottom light-blocking layer in the at least two light-blocking layers, the first small holes in other light-blocking layers correspond one-to-one to the pixel units.

[0023] In a possible implementation manner, the lateral light-blocking layer is a film layer formed by electroplating or chemical plating.

[0024] In one possible implementation, the lateral light-blocking layer is a film layer formed by sputtering or evaporation, and the material of the film layer is tungsten, chromium or nickel; or the lateral light-blocking layer is a stacked structure formed by sputtering or evaporation, the metal in the stacked structure is chromium or titanium, and the oxide in the stacked structure is silicon dioxide or titanium dioxide.

[0025] In a possible implementation manner, the thickness of the lateral light-blocking layer is 1 to 3 um.

[0026] In a possible implementation manner, the second small hole is in a rounded rectangle or a circle.

[0027] In a second aspect, an electronic device is provided, including a display screen and a fingerprint detection device as in any possible implementation manner of the first aspect.

[0028] Wherein, the fingerprint detection device is arranged below the display screen.

[0029] In the fingerprint detection device provided in the embodiment of the present application, since a lateral light-blocking layer is provided to block light leakage, the imaging quality can be improved and the effect of fingerprint detection can be improved, especially in a strong light scene with strong external ambient light, which can greatly improve the recognition effect of the fingerprint detection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The present invention is a structural schematic diagram of a fingerprint detection device.

[0031] Figure 2 yes Figure 1 Top view of the .

[0032] Figure 3 It is a schematic diagram of ambient light at a large angle entering the fingerprint detection device.

[0033] Figure 4 is a schematic diagram of a fingerprint detection device according to an embodiment of the present application.

[0034] Figure 5 is a schematic diagram of another fingerprint detection device according to an embodiment of the present application.

[0035] Figure 6 yes Figure 4 Top view of the .

[0036] Figure 7 yes Figure 5 Top view of the .

[0037] Figure 8 It is an optical simulation diagram of the reflectivity of the lateral light-blocking layer at various wavelengths according to an embodiment of the present application.

[0038] Fig. 9 It is a schematic diagram comparing the total amount of light entering a fingerprint detection device with and without a lateral light-blocking layer according to an embodiment of the present application.

[0039] Fig.10 3 is a schematic diagram comparing the amount of light entering the corresponding microlens with and without a lateral light blocking layer in the fingerprint detection device according to an embodiment of the present application.

[0040] Fig.11 is a schematic diagram of an electronic device according to an embodiment of the present application.

[0041] Fig.12 It is a specific process flow chart of a method for preparing a fingerprint detection device according to an embodiment of the present application.

[0042] Fig.13 It is a specific process flow chart of another method for preparing a fingerprint detection device according to an embodiment of the present application. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0044] It should be understood that the embodiments of the present application can be applied to optical fingerprint systems, including but not limited to optical fingerprint recognition systems and products based on optical fingerprint imaging. The embodiments of the present application are only described using the optical fingerprint system as an example, but should not constitute any limitation to the embodiments of the present application. The embodiments of the present application are also applicable to other systems that use optical imaging technology, etc.

[0045] As a common application scenario, the optical fingerprint system provided in the embodiment of the present application can be applied to smart phones, tablet computers and other mobile terminals or other electronic devices with display screens; more specifically, in the above electronic devices, the fingerprint recognition device can be specifically an optical fingerprint device, which can be set in a partial area or the entire area below the display screen, thereby forming an under-display optical fingerprint system. Alternatively, the fingerprint recognition device can also be partially or fully integrated into the display screen of the electronic device, thereby forming an in-display optical fingerprint system.

[0046] Figure 1This is a schematic diagram of a fingerprint detection device according to an embodiment of the present application. The fingerprint detection device 10 can be used to be arranged below a display screen of an electronic device, and includes a microlens array, at least two light-blocking layers, a pixel unit array, and a filter layer.

[0047] A microlens array 100, wherein the microlens array 100 includes a plurality of microlenses, for example, a microlens 101 and a microlens 102. For the sake of simplicity, only two microlenses are shown in the embodiment of the present application. It can be understood that the microlens array 100 may include M×N microlenses;

[0048] At least two light blocking layers 110 are disposed below the microlens array 100. Figure 1 Only two light-blocking layers are shown: light-blocking layer 111 and light-blocking layer 112. It can be understood that more than two light-blocking layers can be designed according to actual conditions, and the embodiments of the present application are not limited thereto. The light-blocking layer 111 includes a first small hole 1111 and a second small hole 1112, and the light-blocking layer 112 includes a first small hole 1121, a first small hole 1122, a first small hole 1123, and a first small hole 1124. The first small hole in the light-blocking layer is used to form a light-guiding channel with a microlens to guide light signals for fingerprint recognition. Each of the at least two light-blocking layers 110 includes at least one first pinhole corresponding to each microlens in the microlens array 100, for example, the microlens 101 corresponds to the first pinhole 1111 in the light-blocking layer 111, and the microlens 101 corresponds to multiple first pinholes in the light-blocking layer 112, such as the first pinhole 1121 and the first pinhole 1122. Optionally, the microlens 101 can correspond to 4, 9, 16, etc. first pinholes in the light-blocking layer 112.

[0049] For reference Figure 2 , Figure 2 for Figure 1 The top view of the fingerprint detection device 10 shown in FIG. 1 shows only four microlenses, namely, microlens 101, microlens 102, microlens 103 and microlens 104. It can be understood that Figure 1 for Figure 2 The cross-sectional view along the diagonal direction is the line connecting the centers of microlens 101 and microlens 102. Figure 1 Only the light path sections corresponding to the microlens 101 and the microlens 102 can be seen. Some first small holes in the light blocking layer 112 are shown, including the first small hole 1121, the first small hole 1122, the first small hole 1123, the first small hole 1124, the first small hole 1125, the first small hole 1126, the first small hole 1127 and the first small hole 1128. Figure 2The microlens 101 corresponds to the four first pinholes in the light blocking layer 112, namely, the first pinhole 1121, the first pinhole 1122, the first pinhole 1125 and the first pinhole 1126, and the microlens 102 corresponds to the four first pinholes in the light blocking layer 112, namely, the first pinhole 1123, the first pinhole 1124, the first pinhole 1127 and the first pinhole 1128. Since the optical path structure corresponding to each microlens is the same, the microlens 101 is taken as an example for description below.

[0050] Optionally, the microlens 101 may also correspond to a plurality of first small holes ( Figure 2 The light blocking layer 111 is not shown in the figure, for example, 4, 9, 16, etc.

[0051] Optionally, the number of first pinholes in the light blocking layer 111 corresponding to the microlens 101 can be equal to the number of first pinholes in the light blocking layer 112 corresponding to the microlens 101, and the diameter of the first pinholes in the light blocking layer 111 can be larger than the diameter of the first pinholes in the light blocking layer 112 to guide the light signal with a larger field of view and improve the fingerprint recognition effect.

[0052] Continue to refer Figure 1 , a pixel unit array 120 is disposed below at least two light blocking layers 110, and the pixel unit array 120 includes at least one pixel unit corresponding to each microlens 101, such as Figure 1 The microlens 101 corresponds to the pixel unit 121 and the pixel unit 122, and the microlens 102 corresponds to the pixel unit 123 and the pixel unit 124. The pixel unit is used to receive the light signal that is converged by the corresponding microlens and guided through the first pinholes in at least two light-blocking layers. For example, the pixel unit 122 is used to receive the light signal 1011 that is converged by the corresponding microlens 101 and guided through the first pinhole 1111 in the light-blocking layer 111 and the first pinhole 1122 in the light-blocking layer 112, and the pixel unit 121 is used to receive the light signal 1011 that is converged by the corresponding microlens 101 and guided through the first pinhole 1111 in the light-blocking layer 111 and the first pinhole 1121 in the light-blocking layer 112. Figure 1 (not shown) wherein the bottom light-blocking layer of the at least two light-blocking layers 110, that is, the first small holes in the light-blocking layer 112 correspond to the pixel units one by one. Figure 2 , the first small holes 1121 to the first small holes 1128 in the light blocking layer 112 correspond to the pixel units 121 to the pixel units 128 respectively. For example, the microlens 101 corresponds to the pixel units 121, 122, 125 and 126, and the microlens 102 corresponds to the pixel units 123, 124, 127 and 128, that is, one microlens corresponds to four pixel units. It can be understood that according to actual conditions, one microlens can also correspond to 9, 16, etc. pixel units.

[0053] Continue to refer Figure 1 The filter layer 130 is arranged above the bottom light-blocking layer, for example, between the bottom light-blocking layer and the upper light-blocking layer 111 of the bottom light-blocking layer. The filter layer 130 is used to filter out non-target light signals and transmit target light signals, such as the infrared filter layer, which is used to filter out infrared light, and the wavelength band of the filtered light signal is about 600-1100nm. Figure 1 An example of two light-blocking layers is shown in FIG. 1 , and therefore, the filter layer 130 can be disposed between the two light-blocking layers.

[0054] Continue to refer Figure 1 , after the light signal 1012 is converged by the microlens 102, it passes through the first small hole 1112 and the first small hole 1122 to reach the pixel unit 122. The pixel unit 122 should receive the light signal converged or guided by its corresponding microlens 101, but at this time, the pixel unit 122 receives the light signal 1012 guided by the non-corresponding microlens, that is, the microlens 102 adjacent to the microlens 101, and this part of the light signal is unnecessary, which is called leakage light. This part of the leakage light will affect the effect of fingerprint imaging. In other words, the pixel unit needs to receive the light signal guided by the corresponding microlens, or the light signal at a specific angle. For example, the pixel unit 122 receives the light signal guided by the light guide channel in a specific direction formed by the microlens 101, the first small hole 1111 and the first small hole 1122, and the light signal guided by the non-corresponding microlens will reduce the contrast of the fingerprint image and affect the overall fingerprint imaging effect. Therefore, this part of the light signal needs to be filtered out to improve the fingerprint recognition effect.

[0055] Similarly, when there are gaps between the microlenses in the microlens array 100, part of the light signal can enter the pixel unit through the gaps between the microlenses. Since this part of the light signal is not guided by the corresponding microlens, it is also considered as light leakage, which will affect the fingerprint imaging effect. Figure 1 In the figure, the leaked light signal 1013 enters the fingerprint detection device through the gap between the microlenses and passes through the first small hole 1112 and the first small hole 1122 in turn to reach the pixel unit 122. Specifically, when the large-angle light signal guided by other positions other than the corresponding microlenses is incident on the infrared filter layer, the cutoff spectral curve of the infrared filter layer will be blue-shifted, resulting in a decrease in its filtering performance for infrared light, which increases the component of the incident light signal that passes through, especially the infrared light transmittance. When the underlying light-blocking layer is the metal layer of the pixel unit, that is, the internal circuit layer of the pixel unit, the light signal will be continuously reflected between the metal layer and the infrared filter layer, eventually causing a portion of the leaked light to enter the non-corresponding pixel unit through the small holes in the underlying light-blocking layer, affecting the fingerprint imaging. For example Figure 1In the figure, after the optical signals 1012 and 1013 enter the fingerprint detection device, they are continuously reflected between the filter layer 130 and the bottom light blocking layer 112 (metal layer), and then enter the pixel unit 122 through the first small hole 1122. Since the area of ​​the small holes on the metal layer accounts for a very small proportion of the total area of ​​the metal layer, generally not exceeding 10%, the main way for the leakage light to enter the pixel unit is to receive the leakage light signal that is continuously reflected between the metal layer and the infrared filter layer.

[0056] Under normal circumstances, the influence of light leakage can be eliminated by filtering and noise reduction. Even if the light leakage enters the pixel unit after multiple reflections, it will not affect the final imaging effect. There are two main reasons for this:

[0057] 1. These light signals that are reflected multiple times and enter the pixel unit have no angle selectivity, so they appear as disordered and messy background noise in the final image. As long as they are not overexposed, they can be filtered out by the post-processing algorithm.

[0058] 2. Because the fingerprint recognition area on the display screen is pressed by a finger, the light will be greatly weakened. Generally, the light passing through the finger is weak, and the light energy after multiple reflections is very small. It will not affect the image quality within the light sensitivity of the pixel unit (equivalent to the range).

[0059] However, when the external light is strong, the energy of the strong light after passing through the finger is still large, and the strong light at oblique incidence will bypass the fingertip and enter the surface of the fingerprint detection device, for example Figure 3 As shown, when a finger is pressed on the display screen for fingerprint detection, the energy of the light signal 1014 after passing through the finger is still large enough to enter the fingerprint detection device 10, and the large-angle light signal 1015 bypasses the fingertip and also enters the fingerprint detection device 10. Even if a filter layer is used, the influence of light leakage cannot be effectively eliminated. These light leakages will greatly affect the imaging of the pixel unit. When the energy of the leakage light exceeds the photosensitivity of the pixel unit, overexposure will occur, and fingerprint detection cannot be performed.

[0060] In order to improve the recognition effect of the fingerprint detection device in a strong light scene and improve the user experience, the present application provides a fingerprint detection device, which is used to be arranged under the display screen of an electronic device, and is characterized by comprising:

[0061] A microlens array comprising a plurality of microlenses;

[0062] At least two light-blocking layers are disposed below the microlens array, each of the at least two light-blocking layers comprising at least one first pinhole corresponding to each microlens in the microlens array;

[0063] A pixel unit array is arranged below the at least two light-blocking layers, the pixel unit array includes at least one pixel unit corresponding to each of the microlenses, the pixel unit is used to receive the light signal converged by the corresponding microlens and guided through the first small holes in the at least two light-blocking layers, wherein the bottom light-blocking layer in the at least two light-blocking layers is a metal layer, and the first small holes in the bottom light-blocking layer correspond to the pixel units one by one;

[0064] A light filter layer is arranged between the bottom light-blocking layer and a light-blocking layer above the bottom light-blocking layer;

[0065] A lateral light-blocking layer is arranged on the upper surface of the non-opening area of ​​the underlying light-blocking layer and is located below the filter layer. The height of the lateral light-blocking layer is greater than or equal to 90% of the distance between the underlying light-blocking layer and the filter layer. The lateral light-blocking layer includes at least one second small hole corresponding to each microlens, and the size of the second small hole is greater than the size of the first small hole in the underlying light-blocking layer.

[0066] like Figure 4 As shown, the fingerprint detection device 20 includes:

[0067] The microlens array 100 includes a plurality of microlenses, for example, a microlens 101 and a microlens 102. For simplicity, the present embodiment only shows two microlenses. It can be understood that the microlens array 100 may include M×N microlenses.

[0068] At least two light blocking layers 110 are disposed below the microlens array 100. Figure 4 Only two light-blocking layers are shown: light-blocking layer 111 and light-blocking layer 112. It can be understood that more than two light-blocking layers can be designed according to actual conditions, and the embodiments of the present application are not limited thereto. The light-blocking layer 111 includes a first small hole 1111 and a first small hole 1112, and the light-blocking layer 112 includes a first small hole 1121, a first small hole 1122, a first small hole 1123, and a first small hole 1124. The first small hole in the light-blocking layer is used to form a light-guiding channel with a microlens to guide the light signal for fingerprint recognition.

[0069] Each of the at least two light-blocking layers 110 includes at least one first pinhole corresponding to each microlens in the microlens array 100, for example, the microlens 101 corresponds to the first pinhole 1111 in the light-blocking layer 111, and the microlens 101 corresponds to a plurality of first pinholes in the light-blocking layer 112, for example, the first pinhole 1121 and the first pinhole 1122. The optional microlens 101 may correspond to 4, 9, 16, etc. first pinholes in the light-blocking layer 112. Figure 2 , Figure 2 It can also be Figure 4The top view of the fingerprint detection device 20 shown in FIG. 1 shows only four micro lenses for illustration, micro lenses 101 to 104, which can be understood as follows: Figure 4 for Figure 2 The cross-sectional view along the diagonal direction is the line connecting the centers of microlens 101 and microlens 102. Figure 4 Only the light path sections corresponding to the microlens 101 and the microlens 102 can be seen. Also shown are some first small holes in the light blocking layer 112, namely, the first small holes 1121 to the first small holes 1128. Figure 2 The medium microlens 101 corresponds to four first small holes in the light blocking layer 112 , namely, a first small hole 1121 , a first small hole 1122 , a first small hole 1125 and a first small hole 1126 .

[0070] Optionally, the microlens 101 may also correspond to a plurality of first small holes in the light blocking layer 111 , for example, 4, 9, 16, etc.

[0071] Optionally, the number of first pinholes in the light blocking layer 111 corresponding to the microlens 101 can be equal to the number of first pinholes in the light blocking layer 112 corresponding to the microlens 101, and the diameter of the first pinholes in the light blocking layer 111 can be larger than the diameter of the first pinholes in the light blocking layer 112 to guide the light signal with a larger field of view and improve the fingerprint recognition effect.

[0072] Continue to refer Figure 4 , a pixel unit array 120 is disposed below at least two light blocking layers 110, and the pixel unit array 120 includes at least one pixel unit corresponding to each microlens 101, such as Figure 4 The microlens 101 corresponds to pixel unit 121 and pixel unit 122, and the microlens 102 corresponds to pixel unit 123 and pixel unit 124. The pixel unit is used to receive the light signal that is converged by the corresponding microlens and guided through the first pinhole in at least two light-blocking layers. For example, the pixel unit 122 is used to receive the light signal 1011 that is converged by the corresponding microlens 101 and guided through the first pinhole 1111 in the light-blocking layer 111 and the first pinhole 1122 in the light-blocking layer 112, and the pixel unit 121 is used to receive the light signal that is converged by the corresponding microlens 101 and guided through the first pinhole 1111 in the light-blocking layer 111 and the first pinhole 1121 in the light-blocking layer 112 (4 is not shown in the figure). Among them, the bottom light-blocking layer in the at least two light-blocking layers 110, that is, the first pinhole in the light-blocking layer 112 corresponds to the pixel unit one by one. Refer to Figure 2, the first small holes 1121 to the first small holes 1128 in the light blocking layer 112 correspond to the pixel units 121 to the pixel units 128 respectively. Among them, the microlens 101 corresponds to the pixel units 121, 122, 125 and 126, and the microlens 102 corresponds to the pixel units 123, 124, 127 and 128, that is, one microlens corresponds to 4 pixel units. It can be understood that according to actual conditions, one microlens can also correspond to 9, 16 or other numbers of pixel units, that is, each microlens corresponds to multiple pixel units.

[0073] Figure 4 The case in which each microlens corresponds to a plurality of pixel units is given in the figure. Of course, each microlens may correspond to one pixel unit and one first small hole in each of the at least two light blocking layers.

[0074] As an optional embodiment, the microlens may correspond to a first opening in each of the at least two light blocking layers 110 and correspond to a pixel unit in the pixel array 120 .

[0075] See also Figure 5 , the microlens 101 corresponds to the first pinhole 1111 in the light blocking layer 111, the first pinhole 1129 in the light blocking layer 112, and the pixel unit 1291 in the pixel unit array 120; the microlens 102 corresponds to the first pinhole 1112 in the light blocking layer 111, the first pinhole 1130 in the light blocking layer 112, and the pixel unit 1292 in the pixel unit array 120. That is, the microlens, the first pinhole, and the pixel unit are in one-to-one correspondence. Figure 5 The optical path shown in the figure can guide an optical signal in a specific direction, such as an optical signal in a vertical direction or an optical signal in an inclined direction. The direction of the optical signal takes the plane where the pixel unit array is located as a reference plane.

[0076] Continue to refer Figure 4 The filter layer 130 is arranged above the bottom light-blocking layer, for example, between the bottom light-blocking layer and the upper light-blocking layer 111 of the bottom light-blocking layer. The filter layer 130 is used to filter out non-target light signals and transmit target light signals, such as the infrared filter layer, which is used to filter out infrared light, and the wavelength band of the filtered light signal is about 600-1100nm. Figure 4 An example of two light-blocking layers is shown in FIG. 1 , and therefore, the filter layer 130 can be disposed between the two light-blocking layers.

[0077] The lateral light blocking layer 140 is arranged on the upper surface of the non-perforated area of ​​the bottom light blocking layer and is located below the filter layer 130. The height of the lateral light blocking layer 140 is greater than or equal to 90% of the distance between the bottom light blocking layer and the filter layer 130. That is, when the distance between the bottom light blocking layer and the filter layer 130 is H, the height of the lateral light blocking layer is greater than or equal to 0.9H, or the distance between the upper surface of the lateral light blocking layer 140 and the lower surface of the filter layer 130 is less than or equal to 0.1H. When there is a gap between the lateral light blocking layer and the filter layer, a transparent medium layer can be arranged in the gap. By arranging the lateral light blocking layer 140, it is possible to effectively block the leakage light guided by the gap between non-corresponding microlenses or microlenses, for example Figure 4 The optical signal 1012 guided by the non-corresponding microlens 102 and the optical signal 1013 entering the fingerprint detection device 20 through the gap between the microlenses are blocked by the lateral light blocking layer 140, so that they will not be Figure 1 or Figure 3 The light also enters the pixel unit 122 through multiple reflections, so the setting of the lateral light blocking layer can improve the effect of fingerprint imaging, thereby improving the accuracy of fingerprint recognition.

[0078] As an optional embodiment, the lateral light blocking layer is located on the lower surface of the filter layer. That is to say, the lateral light blocking layer 140 adopts a closed design and is arranged between the upper surface of the non-opening area of ​​the bottom light blocking layer 112 and the lower surface of the filter layer 130, that is, the height of the lateral light blocking layer 140 is equal to the distance between the bottom light blocking layer 112 and the filter layer 130. When the distance between the bottom light blocking layer 112 and the filter layer 130 is H, the height of the lateral light blocking layer is equal to H. Through the closed lateral light blocking layer design, light leakage can be completely blocked, and the fingerprint imaging effect can be greatly improved.

[0079] In addition, the lateral light blocking layer 140 includes at least one second small hole corresponding to each of the micro lenses, Figure 2 , Figure 4 and Figure 6 ,in Figure 6 for Figure 4 A top view of Figure 2 The difference is Figure 6 A portion of the second small hole of the lateral light blocking layer 140 is shown, and for the sake of simplicity, Figure 6The relevant figure marks of the pixel unit have been deleted. Microlenses 101 to 104 correspond to the second pinhole 1401, the second pinhole 1402, the second pinhole 1403, and the second pinhole 1404 in the lateral light blocking layer 140, respectively; taking microlens 101 as an example, microlens 101 corresponds to one second pinhole 1401 in the lateral light blocking layer 140, corresponds to four first pinholes in the light blocking layer 112, and corresponds to four pixel units in the pixel unit array 120. That is to say, one second pinhole in the lateral light blocking layer corresponds to four first pinholes in the bottom light blocking layer. Since the pixel units correspond one-to-one to the first pinholes in the bottom light blocking layer, at this time, one second pinhole in the lateral light blocking layer corresponds to four pixel units in the pixel unit array 120 ( Figure 6 No reference numerals are added, see Figure 2 ).

[0080] Optionally, each microlens corresponds not only to 4 pixel units, but also to a plurality of pixel units of other numbers, each microlens corresponds to a plurality of pixel units, and the second small holes correspond to the microlenses one-to-one.

[0081] Optionally, each microlens corresponds to a plurality of pixel units, and the second small holes correspond to the pixel units one-to-one.

[0082] Optionally, except for the bottom light-blocking layer, the other light-blocking layers of the at least two light-blocking layers include a first small hole corresponding to each microlens.

[0083] Optionally, each of the at least two light-blocking layers includes a plurality of first small holes corresponding to each microlens.

[0084] Optionally, the top light-blocking layer of the at least two light-blocking layers includes a first small hole corresponding to each microlens.

[0085] Optionally, in the at least two light-blocking layers, except for the top light-blocking layer and the bottom light-blocking layer, the other light-blocking layers include a plurality of first small holes corresponding to each microlens, that is, the first small holes in the other light-blocking layers correspond one-to-one to the pixel units.

[0086] Optionally, the shape of the second small hole in the lateral light blocking layer 140 can be as follows: Figure 6 As shown in the rounded rectangle, setting the second opening into a rounded rectangle can block light leakage to the greatest extent, while also ensuring the amount of light entering the pixel unit, thereby ensuring the effect of fingerprint imaging.

[0087] Optionally, the second small hole may be in a circular, elliptical or other shapes. The second small hole is in a circular or elliptical shape, and the manufacturing process is simple, and the manufacturing cost can be well controlled.

[0088] As an optional embodiment, each microlens corresponds to a pixel unit, and a first small hole and a second small hole in each light blocking layer correspond to the pixel units one by one.

[0089] Figure 7 for Figure 5 , and shows a microlens, a portion of the first small hole in the light blocking layer 112, a portion of the second small hole in the lateral light blocking layer, and a pixel unit. Figure 5 for Figure 7 The cross-sectional view along the diagonal line is the line connecting the centers of microlens 101 and microlens 102. Figure 5 Only the optical path portion corresponding to microlens 101 and microlens 102 can be seen. Figure 7 It is shown that the microlens 101, the microlens 102, the microlens 103 and the microlens 104 correspond to the first pinhole 1129, the first pinhole 1130, the first pinhole 1131 and the first pinhole 1132 in the light blocking layer 112 respectively; the microlenses 101 to 104 correspond to the second pinhole 1401, the second pinhole 1402, the second pinhole 1403 and the second pinhole 1404 in the lateral light blocking layer 140 respectively; and the microlenses 101 to 104 correspond to the pixel unit 1291, the pixel unit 1292, the pixel unit 1293 and the pixel unit 1294 in the pixel unit array 120 respectively. That is, the microlens 101 corresponds to one second pinhole 1401 in the lateral light blocking layer 140, one first pinhole 1129 in the light blocking layer 112, and one pixel unit 1291 in the pixel unit array. That is, one second small hole 1401 in the lateral light-blocking layer corresponds to one first small hole 1129 in the bottom light-blocking layer, and corresponds to one pixel unit 1291 in the pixel unit array. Figure 5 Each microlens corresponds to a first small hole in the light blocking layer 111 , for example, the microlens 101 corresponds to the first small hole 1111 in the light blocking layer 111 .

[0090] The shape of the second small hole in the embodiment of the present application can also be a rounded rectangle, a circle, an ellipse or other shapes. Setting the second opening to a rounded rectangle can block light leakage to the greatest extent, while also ensuring the amount of light entering the pixel unit and ensuring the effect of fingerprint imaging. The circular or elliptical shape has a simple manufacturing process and can well control the manufacturing cost.

[0091] As an optional embodiment, the size of the second small hole is larger than the size of the first small hole in the bottom light-blocking layer. Therefore, when the lateral light-blocking layer blocks light leakage, it will not block the light signal guided by the corresponding microlens, thereby improving the fingerprint recognition effect.

[0092] Optionally, the sizes of the first small holes in at least two light-blocking layers decrease from top to bottom.

[0093] The optional second small hole has a size no smaller than that of the first small hole of the other light-blocking layers except the bottom light-blocking layer in the at least two light-blocking layers. In this way, the second small hole will not block the light signal guided by the light-blocking layer on the upper layer, and can block the light leakage signal, thereby improving the fingerprint imaging effect.

[0094] Optionally, the bottom light-blocking layer is a metal layer, and the metal layer is the internal circuit layer of the pixel unit. This can improve the integration of the fingerprint detection device by reusing the internal circuit layer of the pixel unit as the bottom light-blocking layer. When the internal circuit layer is used as the bottom light-blocking layer, it can be closer to the pixel unit, thereby achieving better light-shielding effect and avoiding crosstalk between optical signals of different microlenses.

[0095] Optionally, the lateral light-blocking layer is a film layer formed by black nickel or black chromium. The bottom light-blocking layer can be used as a seed layer, and the lateral light-blocking layer is prepared by electroplating or chemical plating. The material of the bottom light-blocking layer is an aluminum-copper alloy (Al-Cu), and the proportion of copper Cu is between 0.05-0.5%. That is to say, the lateral light-blocking layer is a film layer formed by electroplating or chemical plating. Among them, black nickel or black chromium is a low-reflection metal that can effectively block light leakage.

[0096] Optionally, the lateral light-blocking layer is a film layer formed by a metal (such as tungsten, chromium, nickel, etc.), or a laminated structure formed by a metal and an oxide (a combination of one or more metals such as chromium Cr, titanium Ti, etc., and inorganic oxides such as silicon dioxide SiO2, titanium dioxide TiO2, etc.). The lateral light-blocking layer can be deposited and prepared by sputtering, evaporation, or cross-mixing. In other words, the lateral light-blocking layer is a film layer formed by sputtering or evaporation, and the material of the film layer is tungsten, chromium, or nickel, etc.; or the lateral light-blocking layer is a laminated structure formed by sputtering or evaporation, and the metal in the laminated structure is chromium or titanium, etc., and the oxide in the laminated structure is silicon dioxide or titanium dioxide, etc. Similarly, tungsten, chromium, nickel, etc. are low-reflection metals that can effectively block light leakage. Oxides such as silicon dioxide or titanium dioxide can enhance the connectivity of the laminated structure.

[0097] In order to ensure the thickness of the overall fingerprint detection device, the thickness of the lateral light blocking layer, or the thickness of the coating layer, film layer or laminated structure may be 1 to 3 um.

[0098] Optionally, the lateral width of the lateral light-blocking layer is 0.5-5 um. The lateral width here refers to the lateral width of the non-opening area except the opening area of ​​the lateral light-blocking layer.

[0099] Optionally, the fingerprint detection device in the embodiment of the present application may further include a passivation layer, which is located inside the second small hole. The passivation layer is a transparent layer that can guide the light signal of the corresponding microlens to enter the corresponding pixel unit through the first small hole. In addition, the passivation layer also protects the underlying light-blocking layer. It is understandable that Figure 4 or Figure 5 In the figure, the passivation layer, metal layer and pixel array are the internal structure of the fingerprint chip, or the internal structure of the wafer. The lateral light blocking layer is further prepared by patterning the passivation layer using a photolithography process. Using the thickness of the passivation layer to prepare the lateral light blocking layer can improve the integration of the fingerprint detection device. For details, please refer to the following Fig.12 , Fig.13 The corresponding content.

[0100] Optionally, the transmittance of the lateral light-blocking layer to visible light is lower than 1%, and the reflectivity at different angles is lower than 10%, for example, 2% to 10%, thereby greatly eliminating or improving the light leakage problem.

[0101] Figure 8 As shown, taking a lateral light-blocking layer of a material as an example, when its thickness is 1um, at different reflection angles, specifically 15 degrees, 45 degrees and 60 degrees, the average reflectivity of each wavelength spectrum is 4% to 10%, and the transmittance is less than 0.1%. The horizontal axis is the wavelength of the light signal, and the vertical axis is the reflectivity of the lateral light-blocking layer to the light signal.

[0102] As an optional embodiment, the fingerprint detection device further includes a first transparent medium layer, which is located between the microlens array and the top light-blocking layer of the at least two light-blocking layers, and in the first small hole in the top light-blocking layer. It can be understood that the first transparent medium layer can flatten the top light-blocking layer and connect the microlens array. The first transparent medium layer can also be called a flat layer. When there are gaps between the microlenses, the leakage light actually enters the fingerprint detection device from the first transparent medium layer or the flat layer between the microlenses. Figure 4 or Figure 5 The fingerprint detection device 20 or 30 further includes a first transparent medium layer 151 , which is located between the microlens array 100 and a top light-blocking layer 111 of at least two light-blocking layers 110 , and in a first small hole in the top light-blocking layer 111 .

[0103] Optionally, the fingerprint detection device further includes a second transparent medium layer, which is used to connect the light filter layer and the upper light blocking layer of the bottom light blocking layer, so that the light filter layer and the upper light blocking layer of the bottom light blocking layer are more closely connected, thereby ensuring the connection reliability of the fingerprint detection device. Figure 4 or Figure 5The fingerprint detection device 20 or 30 further includes a second transparent medium layer 152 for connecting the filter layer 130 and the light blocking layer 111. Figure 4 , Figure 5 The two embodiments provide only two light-blocking layers. Therefore, when the at least two light-blocking layers are two light-blocking layers, the second transparent medium layer is located between the filter layer and the top light-blocking layer.

[0104] In order to more clearly demonstrate the effect of setting a lateral light-blocking layer in the fingerprint detection device, the following is a comparison of the fingerprint detection device under 10w Lux strong light based on the sunlight spectrum. Figure 1 and Figure 4 The simulation results are shown in Table 1. Figure 4 With the lateral light-blocking layer, the total amount of strong light entering is Figure 1 That is, when no lateral light-blocking layer is added, the amount of light entering the flat layer is reduced by 24%, the amount of light entering the non-corresponding microlens is reduced by 35%, and the amount of light entering the corresponding microlens is increased by 1%, which is almost unchanged. The simulation results to a certain extent illustrate that adding a closed lateral light-blocking layer between the bottom light-blocking layer 112 and the filter layer 130 can effectively eliminate the reflection of light entering from the non-corresponding microlens and the flat layer between the filter layer and the bottom light-blocking layer, thereby reducing the probability of light leakage entering the pixel unit.

[0105] Table 1

[0106] No lateral light blocking layer With lateral light blocking layer Change Total light intake 6510.29 4944.53 -24％ Light intake of flat layer 1212.35 884.35 -27％ Corresponding microlens 1673.88 1694.9 1％ Non-corresponding microlenses 3624.06 2365.28 -35％

[0107] Fig. 9 The figure shows the total amount of light entering when there is or is not a lateral light-blocking layer. The horizontal axis is the wavelength of the optical signal, the vertical axis is the amount of light entering, the solid line represents the total amount of light entering when there is no lateral light-blocking layer, and the dotted line represents the total amount of light entering when there is a lateral light-blocking layer. It can be seen that after adding the lateral light-blocking layer, the total amount of light entering from the external strong light is significantly reduced.

[0108] Fig.10 A schematic diagram of the amount of light entering the corresponding microlens when there is or is not a lateral light-blocking layer is shown, wherein the horizontal axis is the wavelength of the light signal, the vertical axis is the amount of light entering, the solid line represents the amount of light entering the corresponding microlens when there is a lateral light-blocking layer, and the dotted line represents the amount of light entering the corresponding microlens when there is no lateral light-blocking layer. It can be seen that the two curves almost overlap, and whether or not the lateral light-blocking layer is added has almost no effect on the amount of light entering the corresponding microlens. The light signal guided by the corresponding microlens is exactly the light signal required for fingerprint detection. Combined with Table 1, it can be seen that adding a lateral light-blocking layer will greatly reduce the leakage light signal guided by the non-corresponding microlens and the flat layer. Therefore, in the embodiment of the present application, adding a lateral light-blocking layer can reduce the impact of light leakage on fingerprint imaging and improve the effect of fingerprint detection.

[0109] The present application also provides an electronic device, comprising: a display screen and the aforementioned fingerprint detection device; wherein the fingerprint detection device is arranged below the display screen.

[0110] See also Fig.11 The electronic device 40 includes a display screen 410 and a fingerprint detection device 420, and the fingerprint detection device 420 is disposed below the display screen 410. The fingerprint detection device 420 may be the aforementioned fingerprint detection device 20 or 30, and is located in the display area of ​​the display screen 410.

[0111] As an optional embodiment, the display screen 410 may be a display screen with a self-luminous display unit, such as an organic light-emitting diode (OLED) display screen or a micro-light-emitting diode (Micro-LED) display screen. Taking the OLED display screen as an example, the fingerprint detection device 420 may use the display unit (i.e., OLED light source) of the OLED display screen 410 as an excitation light source for fingerprint detection.

[0112] In other embodiments, the fingerprint detection device 420 may also use a built-in light source or an external light source to provide an optical signal for fingerprint detection. In this case, the fingerprint detection device 420 may be applicable to a non-self-luminous display screen, such as a liquid crystal display screen or other passive light-emitting display screens.

[0113] It should be understood that, in a specific implementation, the electronic device 40 further includes a transparent protective cover plate, which may be a glass cover plate or a sapphire cover plate, which is located above the display screen 410 and covers the front of the electronic device 40. Because, in the embodiment of the present application, the so-called finger pressing on the display screen 410 actually refers to pressing the cover plate above the display screen 410 or the surface of the protective layer covering the cover plate.

[0114] The present application also provides a method for preparing a fingerprint detection device, comprising:

[0115] S101, defining the shape of a second small hole of the lateral light blocking layer in the passivation layer above the metal layer of the pixel unit, removing the passivation layer outside the shape of the second small hole until the metal layer is exposed, wherein the size of the second small hole is larger than the size of the first small hole of the metal layer;

[0116] The specific process flow chart of the preparation method of the fingerprint detection device of the embodiment of the present application can be found in Fig.12 .

[0117] Optionally, a photolithography process is used to define the second small hole of the lateral light-blocking layer, that is, the passivation layer of the second small hole shape is retained, and the passivation layer except the second small hole is removed. Specifically, only the protective layer is covered on the top of the second small hole shape, and the other areas except the second small hole shape are not covered with the protective layer. The dry etching process can be used to dry-etch the area not covered with the protective layer. Under the premise of ensuring a certain amount of over-etching, the passivation layer not covered by the protective layer will be completely etched until the metal layer is exposed, and the area covered with the protective layer, that is, the area of ​​the second small hole shape, will not be damaged. Finally, the remaining protective layer is removed by the Strip stripping process. The protective layer can be a PR glue layer.

[0118] S102, performing electroplating or chemical plating on the exposed metal layer to form the lateral light blocking layer, wherein the exposed metal layer is a seed layer.

[0119] Since the passivation layer has formed specific patterned grooves before the electroplating or chemical plating process, as described above, only the passivation layer corresponding to the shape of the second small hole is retained, and the passivation layer of other parts is removed. The plating layer or film layer will be graphically grown in the area except the second small hole with the exposed metal layer as the substrate. The thickness of the plating layer is controlled by setting the time or power of the electroplating or chemical plating so that the thickness of the lateral light-blocking layer is less than the thickness of the passivation layer. Optionally, the thickness of the lateral light-blocking layer is greater than or equal to 90% of the thickness of the passivation layer, or the difference between the thickness of the lateral light-blocking layer and the thickness of the passivation layer is less than or equal to 10%. When the thickness of the lateral light-blocking layer is equal to the thickness of the passivation layer, it can completely block light leakage and improve the quality of fingerprint imaging.

[0120] Optionally, the material of the plating layer or film layer used for electroplating or chemical plating is black nickel or black chromium, which is a low-reflective metal and can effectively block light leakage.

[0121] Optionally, the metal layer is a bottom light-blocking layer of the fingerprint detection device, and the material of the bottom light-blocking layer is an aluminum-copper alloy (Al-Cu), and the proportion of copper Cu is between 0.05-0.5%.

[0122] Optionally, the transmittance of the lateral light-blocking layer to visible light is lower than 1%, and the reflectivity at different angles is lower than 10%, for example, 2% to 10%, thereby greatly eliminating or improving the light leakage problem.

[0123] In order to ensure the thickness of the overall fingerprint detection device, the thickness of the lateral light blocking layer, or the thickness of the coating layer and the film layer can be 1 to 3 um. Further, other optical path stacks can be processed on top. For example, a filter layer can be made on the lateral light blocking layer, that is, the coating layer and the second small hole.

[0124] Optionally, the first small holes in the metal layer correspond to the pixel units one by one, and the first small holes are used to guide the light signal to the pixel units to achieve fingerprint detection.

[0125] This application also provides another method for preparing a fingerprint detection device, including:

[0126] S201, defining the shape of a second small hole of the lateral light blocking layer in the passivation layer above the metal layer of the pixel unit, removing the passivation layer outside the shape of the second small hole until the metal layer is exposed, wherein the size of the second small hole is larger than the size of the first small hole of the metal layer;

[0127] This step can be referred to as S101, and will not be described in detail here. Fig.13 .

[0128] S202 , depositing the exposed metal layer to form the lateral light blocking layer.

[0129] The lateral light-blocking layer can be prepared by deposition by sputtering, evaporation or cross-mixing. After deposition, there is also a deposited material (film layer or laminated structure) above the second small hole shape. The uneven deposited material after deposition needs to be ground and flattened to remove the deposited material above the second small hole shape to form a lateral light-blocking layer.

[0130] Optionally, the lateral light-blocking layer is a film layer formed of metal (such as tungsten, chromium, nickel, etc.), or a stacked structure formed of metal and oxide (a combination of one or more metals such as chromium Cr, titanium Ti, etc., and inorganic oxides such as SiO2, TiO2, etc.).

[0131] In order to ensure the thickness of the overall fingerprint detection device, the thickness of the lateral light blocking layer, or the thickness of the film layer or the laminated structure can be 1-3um. Further, other optical path laminates can be processed on top. For example, a filter layer can also be made on the lateral light blocking layer and the second small hole shape.

[0132] The preparation method of the fingerprint detection device in the embodiment of the present application can be applied to Figures 4 to 10 The fingerprint detection device described in the related embodiments can be combined with each other, and the same components or structures, as well as the parameters of the components, etc. are not repeated here.

[0133] It can be understood that the fingerprint detection device of the embodiment of the present application may also include a memory, and the memory may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DR RAM).

[0134] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A fingerprint detection device, used to be arranged under the display screen of an electronic device, characterized in that: include: A microlens array comprising a plurality of microlenses; At least two light-blocking layers are disposed below the microlens array, each of the at least two light-blocking layers comprising at least one first pinhole corresponding to each microlens in the microlens array; A pixel unit array is arranged below the at least two light-blocking layers, the pixel unit array includes at least one pixel unit corresponding to each of the microlenses, the pixel unit is used to receive the light signal converged by the corresponding microlens and guided through the first small holes in the at least two light-blocking layers, wherein the bottom light-blocking layer in the at least two light-blocking layers is a metal layer, and the first small holes in the bottom light-blocking layer correspond to the pixel units one by one; A light filter layer is arranged between the bottom light-blocking layer and a light-blocking layer above the bottom light-blocking layer; A lateral light-blocking layer is arranged on the upper surface of the non-opening area of ​​the underlying light-blocking layer and is located below the filter layer. The height of the lateral light-blocking layer is equal to the distance between the underlying light-blocking layer and the filter layer. The lateral light-blocking layer includes at least one second small hole corresponding to each microlens, and the size of the second small hole is larger than the size of the first small hole in the underlying light-blocking layer.

2. The fingerprint detection device according to claim 1, characterized in that: Each of the microlenses corresponds to a plurality of pixel units, and the second small holes correspond to the microlenses one-to-one, or the second small holes correspond to the pixel units one-to-one.

3. The fingerprint detection device according to claim 1, characterized in that: Each of the microlenses corresponds to a pixel unit and a first small hole in each of the light-blocking layers, and the second small holes correspond to the pixel units one by one.

4. The fingerprint detection device according to claim 1, characterized in that: The lateral light blocking layer is located on the lower surface of the filter layer.

5. The fingerprint detection device according to claim 1, characterized in that: The metal layer is an internal circuit layer of the pixel unit.

6. The fingerprint detection device according to claim 5, characterized in that: The lateral light blocking layer is a film layer formed by black nickel or black chromium.

7. The fingerprint detection device according to claim 5, characterized in that: The lateral light blocking layer is a film layer formed by metal, or a stacked structure formed by metal and oxide.

8. The fingerprint detection device according to any one of claims 1 to 7, characterized in that: The top light-blocking layer of the at least two light-blocking layers comprises a first small hole corresponding to each of the microlenses.

9. The fingerprint detection device according to any one of claims 1 to 7, characterized in that: The fingerprint detection device further comprises a first transparent medium layer, which is located between the microlens array and a top light-blocking layer of the at least two light-blocking layers, and in a first small hole in the top light-blocking layer.

10. The fingerprint detection device according to claim 9, characterized in that: The at least two light-blocking layers are two light-blocking layers, and the fingerprint detection device further comprises a second transparent medium layer, which is located between the filter layer and the top light-blocking layer of the at least two light-blocking layers.

11. The fingerprint detection device according to any one of claims 1 to 7, characterized in that: The size of the second small hole is not smaller than the size of the first small holes in the other light-blocking layers except the bottom light-blocking layer in the at least two light-blocking layers, and the size of the first small holes in the at least two light-blocking layers decreases from top to bottom.

12. The fingerprint detection device according to any one of claims 1 to 7, characterized in that: Except for the top light-blocking layer and the bottom light-blocking layer in the at least two light-blocking layers, the first small holes in the other light-blocking layers correspond to the pixel units one by one.

13. The fingerprint detection device according to claim 6, characterized in that: The lateral light-blocking layer is a film layer formed by electroplating or chemical plating.

14. The fingerprint detection device according to claim 7, characterized in that: The lateral light blocking layer is a film layer formed by sputtering or evaporation, and the material of the film layer is tungsten, chromium or nickel; or The lateral light blocking layer is a stacked structure formed by sputtering or evaporation, the metal in the stacked structure is chromium or titanium, and the oxide in the stacked structure is silicon dioxide or titanium dioxide.

15. The fingerprint detection device according to any one of claims 1 to 7, characterized in that: The thickness of the lateral light-blocking layer is 1-3 um.

16. The fingerprint detection device according to any one of claims 1 to 7, characterized in that: The second small hole is in a rounded rectangle or a circle.

17. An electronic device, characterized in that: include: A display screen and a fingerprint detection device as claimed in any one of claims 1 to 16; Wherein, the fingerprint detection device is arranged below the display screen.

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