CN111837132B

CN111837132B - Fingerprint detection device and electronic equipment

Info

Publication number: CN111837132B
Application number: CN202080001570.6A
Authority: CN
Inventors: 曾红林; 程祥; 张玮; 李顺展
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2024-02-06
Anticipated expiration: 2040-03-27
Also published as: CN111837132A; WO2021189478A1

Abstract

The application provides a fingerprint detection's device, can improve fingerprint detection's performance. The device sets up in electronic equipment's display screen below to be used for the fingerprint detection under the screen, the device includes: the color filter layer comprises a plurality of groups of color filter units, wherein each group of color filter units comprises a red filter unit, and the red filter unit is used for transmitting red light signals returned by fingers; the infrared filter layer is used for blocking red light and infrared light with the cut-off wavelength above, wherein an opening is arranged at a position corresponding to the red filter unit in the infrared filter layer so as not to block the red light signal transmitted through the red filter unit; the optical fingerprint sensor is used for detecting optical signals returned by the finger and transmitted through the color filter layer and the infrared filter layer, wherein the optical signals are used for acquiring fingerprint images of the finger, and the red light signals in the optical signals are used for determining authenticity of the finger and/or used for strong light detection.

Description

Fingerprint detection device and electronic equipment

Technical Field

The embodiment of the application relates to the field of biological feature recognition, and more particularly relates to a fingerprint detection device and electronic equipment.

Background

When the optical fingerprint detection is carried out, the light source irradiates the finger above the display screen, and the optical fingerprint sensor collects the light signals returned by the reflection or scattering of the finger, so that the fingerprint information of the finger is obtained. To avoid interference of red light and infrared light with fingerprint detection, an infrared cut-off (Infrared Radiation Cut, IRC) filter layer needs to be provided. Under strong light environment, the sensing unit of the optical fingerprint sensor is easy to saturate, the performance of fingerprint detection is affected, and at the moment, the influence on fingerprint detection under the strong light environment can be solved by reducing the cut-off wavelength of IRC. However, when the color filter layer is adopted to realize fingerprint anti-counterfeiting, the reduction of the cut-off frequency of the IRC filter layer directly leads to the reduction of red light components, so that the judgment of the authenticity of the finger by the optical fingerprint sensor is affected, and strong light detection is not facilitated, so that the performance of fingerprint detection is affected.

Disclosure of Invention

The embodiment of the application provides a fingerprint detection device and electronic equipment, can promote fingerprint detection's performance.

In a first aspect, an apparatus for fingerprint detection is provided, disposed below a display screen of an electronic device, for use in off-screen fingerprint detection, the apparatus comprising:

The color filter layer comprises a plurality of groups of color filter units, wherein each group of color filter units comprises a red filter unit, and the red filter unit is used for transmitting red light signals returned by fingers;

the infrared filter layer is used for blocking red light and infrared light with the cut-off wavelength above, wherein an opening is arranged at a position corresponding to the red filter unit in the infrared filter layer so as not to block the red light signal transmitted through the red filter unit;

the optical fingerprint sensor is used for detecting optical signals returned by the finger and transmitted through the color filter layer and the infrared filter layer, wherein the optical signals are used for acquiring fingerprint images of the finger, and the red light signals in the optical signals are used for determining authenticity of the finger and/or used for strong light detection.

In a possible implementation, each set of color filter units further comprises a green filter unit and/or a blue filter unit.

In one possible implementation, the plurality of sets of color filter units are distributed in an array over the color filter layer.

In one possible implementation manner, the red light signals transmitted by the red filter units located in the edge area of the color filter layer in the multiple groups of color units are used for determining the authenticity of the finger, and the red light signals transmitted by the red filter units located in the middle area of the color filter layer are used for strong light detection.

In one possible implementation manner, the infrared filter layer is provided with an opening at a position corresponding to the red filter unit in the edge area, and the infrared filter layer is provided with an opening or no opening at a position corresponding to the red filter unit in the middle area.

In one possible implementation, the multiple sets of color filter units are distributed in an edge region of the color filter layer.

In one possible implementation, the filter unit of the edge region may correspond to at least one turn of the optical sensing unit of the edge of the optical fingerprint sensor.

In one possible implementation, the optical fingerprint sensor includes a plurality of optical sensing units, each red filter unit in the color filter layer corresponds to one or more optical sensing units for detecting a red light signal transmitted through the corresponding red filter unit.

In one possible implementation, the optical device further includes an optical path guiding structure, the optical path guiding structure including:

a microlens array including a plurality of microlenses;

at least one light blocking layer, wherein each light blocking layer is provided with a plurality of openings corresponding to the microlenses respectively;

The micro lens is used for converging the optical signals returned by the finger to the corresponding opening in the light blocking layer and transmitting the optical signals to the optical fingerprint sensor through the corresponding opening in the light blocking layer.

In one possible implementation, the color filter layer is located below the microlens array, and the infrared filter layer is disposed between two light blocking layers.

In one possible implementation, a first light blocking layer of the at least one light blocking layer is integrated with the optical fingerprint sensor, and the infrared filter layer is disposed above the first light blocking layer.

In one possible implementation manner, the first light blocking layer is connected with the infrared filtering layer through a transparent medium layer, and the infrared filtering layer is formed on the upper surface of the transparent medium layer through a film plating mode.

In one possible implementation, a second light blocking layer of the at least one light blocking layer is located between the color filter layer and the infrared filter layer.

In one possible implementation, the aperture of the opening in the second light blocking layer, the opening in the infrared filter layer, and the opening in the first light blocking layer decrease sequentially from top to bottom.

In one possible implementation, the optical signal returned by the finger is a vertical optical signal or a tilted optical signal.

In a second aspect, there is provided an apparatus for fingerprint detection disposed below a display screen of an electronic device for off-screen fingerprint detection, the apparatus comprising:

the color filter layer comprises a plurality of red filter units positioned in the edge area of the color filter layer, and the red filter units are used for transmitting red light signals returned by fingers;

an infrared filter layer for blocking red light and infrared light above a cut-off wavelength thereof, wherein an area of the infrared filter layer is smaller than an area of the color filter layer so as not to block the red light signal transmitted through the red filter unit of the edge region;

and the optical fingerprint sensor is used for detecting optical signals which are returned by the finger and pass through the color filter layer and the infrared filter layer, wherein the optical signals are used for acquiring fingerprint images of the finger, and the red light signals which pass through the red filter unit in the edge area in the optical signals are used for strong light detection.

In a possible implementation manner, the color filter layer further comprises a plurality of groups of color filter units located in the middle area of the color filter layer, wherein each group of color filter units comprises a red filter unit, and the red filter unit is used for transmitting red light signals returned by a finger.

In a possible implementation, each set of color filter units further comprises a blue filter unit and/or a green filter unit.

In one possible implementation manner, an opening is provided in the infrared filter layer at a position corresponding to the red filter unit in the middle area, the opening in the infrared filter layer is used for transmitting the red light signal, and the red light signal in the optical signal transmitted through the red filter unit in the middle area is used for fingerprint anti-counterfeiting.

In one possible implementation, the fingerprint sensor includes a plurality of optical sensing units, each red filter unit in the color filter layer corresponds to one or more optical sensing units for detecting a red light signal transmitted through the corresponding red filter unit.

a microlens array including a plurality of microlenses;

In a third aspect, an electronic device is provided, comprising:

The apparatus of the first aspect or fingerprint detection in any possible implementation of the first aspect; or,

the apparatus of the second aspect or any possible implementation of the second aspect.

Based on the technical scheme, the infrared filter layer can block red light and infrared light with the cut-off wavelength above the cut-off wavelength, so that the influence of the infrared light and the red light on fingerprint detection is avoided, and the red filter unit in the color filter layer is used for transmitting red light signals so as to be used for judging the authenticity of the fingerprint. Because the position corresponding to the red filter unit in the infrared filter layer is provided with the opening, the red light signal passing through the red filter unit is prevented from being blocked, the effect on the authenticity judgment of the finger is avoided while the function of the infrared filter layer is effectively realized, and the red light signal passing through the red filter unit can be used for strong light detection, so that the performance of fingerprint detection is improved.

Drawings

Fig. 1 and 2 are schematic diagrams of electronic devices to which embodiments of the present application may be applied.

Fig. 3 and 4 are schematic cross-sectional views of the electronic device shown in fig. 1 and 2, respectively, along A-A'.

Fig. 5 is a filtering of red and infrared light by internal and external IRCs.

Fig. 6 is a schematic block diagram of an apparatus for fingerprint detection according to an embodiment of the present application.

Fig. 7 is a schematic view of a color filter layer according to an embodiment of the present application.

Fig. 8 is a schematic view of a color filter layer according to an embodiment of the present application.

Fig. 9 is a schematic diagram of a color filter layer according to an embodiment of the present application.

Fig. 10 is a possible implementation of the fingerprint detection device shown in fig. 6.

Fig. 11 is another possible implementation of the fingerprint detection device shown in fig. 6.

Detailed Description

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

It should be understood that the embodiments of the present application may be applied to fingerprint systems, including but not limited to optical, ultrasound or other fingerprint recognition systems and medical diagnostic products based on optical, ultrasound or other fingerprint imaging, and are described by way of example only with respect to optical fingerprint systems, but should not be construed as limiting the embodiments of the present application in any way, as the embodiments of the present application are equally applicable to other systems employing optical, ultrasound or other imaging techniques, etc.

As a common application scenario, the optical fingerprint system provided in the embodiments of the present application may be applied to a smart phone, a tablet computer, a mobile terminal with a display screen, and other electronic devices; more specifically, in the above device, the optical fingerprint module may be disposed in a partial area or an entire area Under the display screen, thereby forming an Under-screen (Under-display/Under-screen) optical fingerprint system. Alternatively, the optical fingerprint module may be partially or fully integrated into the display screen of the electronic device, so as to form an In-screen (In-display/In-screen) optical fingerprint system.

The off-screen optical fingerprint detection technology uses light returned from the top surface of the device display assembly for fingerprint sensing and other sensing operations. The returned light carries information of an object, such as a finger, in contact with the top surface, and by collecting and detecting the returned light of the finger, the optical fingerprint detection of a specific optical sensor module positioned below the display screen is realized. The design of the optical sensor module may be such that the desired optical imaging is achieved by properly configuring the optical elements for collecting and detecting the returning light.

Fig. 1 and 2 show schematic diagrams of electronic devices to which embodiments of the present application may be applied. Fig. 1 and 2 are schematic diagrams illustrating the orientation of the electronic device 10, and fig. 3 and 4 are schematic diagrams illustrating a partial cross-section of the electronic device 10 along the direction A-A' shown in fig. 1 and 2, respectively.

The electronic device 10 includes a display 120 and an optical fingerprint module 130. The optical fingerprint module 130 is disposed in a local area below the display screen 120. The optical fingerprint module 130 includes an optical fingerprint sensor including a sensing array 133 having a plurality of optical sensing units 131, which are also referred to as pixels, photosensitive pixels, pixel units, sensing units, and the like in the embodiment of the present application. The sensing area of the sensing array 133 or the sensing area thereof is the fingerprint detection area 103 of the optical fingerprint module 130. As shown in fig. 1, the fingerprint detection area 103 is located in the display area of the display screen 120. In an alternative embodiment, the optical fingerprint module 130 may also be disposed at other locations, such as at the side of the display screen 120 or at an opaque region of the edge of the electronic device 10, and direct the optical signal from at least a portion of the display area of the display screen 120 to the optical fingerprint module 130 via an optical path design such that the fingerprint detection area 103 is actually located in the display area of the display screen 120.

It should be appreciated that the area of the fingerprint detection area 103 may be different from the area of the sensing array 133 of the optical fingerprint module 130, such as by a lens imaging optical path design, a reflective folded optical path design, or other optical path designs such as light converging or reflecting, so that the area of the fingerprint detection area 103 of the optical fingerprint module 130 is larger than the area of the sensing array 133 of the optical fingerprint module 130. In other alternative implementations, if the light path is directed, for example, by light collimation, the fingerprint detection area 103 of the optical fingerprint module 130 may also be designed to substantially conform to the area of the sensing array 133 of the optical fingerprint module 130.

Thus, when a user desires to unlock or otherwise verify the electronic device 10, the user may simply press a finger against the fingerprint detection area 103 on the display 120 to effect fingerprint input. Since fingerprint detection can be implemented in the screen, the electronic device 10 adopting the above structure does not need to have a special reserved space on the front surface to set fingerprint keys such as Home keys, so that a comprehensive screen scheme can be adopted, that is, the display area of the display screen 120 can be basically expanded to the front surface of the whole electronic device 10.

As an alternative implementation, as shown in fig. 2, the optical fingerprint module 130 includes a light detection section 134 and an optical assembly 132. The light detecting portion 134 includes a sensing array 133, and a reading circuit and other auxiliary circuits electrically connected to the sensing array 133, which may be fabricated on a chip (Die) by a semiconductor process to form an optical fingerprint chip or an optical fingerprint sensor, which may be also referred to as a sensor chip or a chip, etc. The sensing array 133 is specifically a photo detector (photo detector) array that includes a plurality of photo detectors distributed in an array that can act as optical sensing units as described above. The optical component 132 may be disposed above the sensing array 133 of the light detecting portion 134, and may specifically include a Filter layer (Filter), a light guiding layer or a light path guiding structure, which may be used to Filter out ambient light penetrating the finger, and other optical elements, and may be used to guide reflected light reflected from the finger surface to the sensing array 133 for optical fingerprint detection.

In particular implementations, the optical assembly 132 may be packaged in the same optical fingerprint component as the light detection portion 134. For example, the optical component 132 may be packaged in the same optical fingerprint chip as the light detecting portion 134, or the optical component 132 may be disposed outside the chip in which the light detecting portion 134 is located, such as attaching the optical component 132 above the chip, or integrating some of the elements of the optical component 132 into the chip.

There are various implementations of the light guiding layer of the optical component 132. For example, the light guiding layer may be embodied as a Collimator (Collimator) layer fabricated on a semiconductor silicon wafer, having a plurality of collimating elements, or an array of apertures, which may be embodied as small holes. Among the reflected light reflected from the finger, the light vertically incident to the collimating unit may pass through the collimating unit and be received by the optical sensing units below the collimating unit, and the light with an excessive incident angle is attenuated by multiple reflections inside the collimating unit, so that each optical sensing unit basically only receives the reflected light reflected from the fingerprint pattern directly above the optical sensing unit, and thus the sensing array 133 can detect the fingerprint image of the finger.

In another implementation, the light guiding layer may also be an optical Lens (Lens) layer having one or more Lens units, for example a Lens group consisting of one or more aspheric lenses, for converging the reflected light reflected from the finger to the sensing array 133 of the light detecting part 134 thereunder, so that the sensing array 133 may image based on the reflected light, thereby obtaining a fingerprint image of the finger. Optionally, a pinhole may be further formed in the optical path of the lens unit, and the pinhole may be matched with the optical lens layer so as to expand the field of view of the optical fingerprint module 130, so as to improve the fingerprint imaging effect of the optical fingerprint module 130.

In other implementations, the light guiding layer may also specifically employ a Micro-Lens layer having a Micro Lens array formed of a plurality of Micro lenses, which may be formed over the sensing array 133 of the light sensing portion 134 by a semiconductor growth process or other process, and each Micro Lens may correspond to one of the sensing cells of the sensing array 133, respectively. Other optical film layers, such as dielectric layers or passivation layers, may also be formed between the microlens layer and the sensing unit. Further, a light blocking Layer, which may also be referred to as a light blocking Layer or a light Shielding Layer (LS), or the like, having an opening formed between its corresponding microlens and the sensing unit may be further included between the microlens Layer and the sensing unit, and the light blocking Layer may block optical interference between adjacent microlenses and the sensing unit, and allow light corresponding to the sensing unit to be condensed into the opening through the microlens and transmitted to the sensing unit through the opening, thereby performing optical fingerprint imaging.

It should be appreciated that several implementations of the light guiding layer described above may be used alone or in combination. For example, a microlens layer may be further provided above or below the collimator layer or the optical lens layer. Of course, when the collimator layer or the optical lens layer is used in combination with the microlens layer, the specific laminated structure or the optical path thereof may need to be adjusted as actually needed.

In the embodiment of the present application, the display screen 120 may be a display screen with a self-luminous display unit, such as an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. Taking an OLED display screen as an example, the optical fingerprint module 130 may use a display unit, that is, an OLED light source, of the OLED display screen 120 located in the fingerprint detection area 103 as an excitation light source for optical fingerprint detection. When the finger 140 is pressed against the fingerprint detection area 103, the display 120 emits a beam of light 111 towards the finger 140 above the fingerprint detection area 103, the light 111 being reflected at the surface of the finger 140 to form reflected light or being scattered inside the finger 140 to form scattered light. In the related patent application, the above-described reflected light and scattered light are also collectively referred to as reflected light for convenience of description. Since the ridge (ridge) 141 and the valley (valley) 142 of the fingerprint have different light reflection capacities, the reflected light 151 from the ridge of the fingerprint and the reflected light 152 from the valley of the fingerprint have different light intensities, and the reflected light is received by the sensing array 133 in the optical fingerprint module 130 and converted into corresponding electrical signals, i.e., fingerprint detection signals after passing through the optical component 132. Fingerprint image data may be obtained based on the fingerprint detection signal and further fingerprint matching verification may be performed to implement an optical fingerprint recognition function in the electronic device 10.

In other implementations, the optical fingerprint module 130 may also use an internal light source or an external light source to provide an optical signal for fingerprint detection. In this case, the optical fingerprint module 130 may be suitable for a non-self-luminous display screen, such as a liquid crystal display screen or other passively luminous display screen. Taking the application to a liquid crystal display having a backlight module and a liquid crystal panel as an example, to support the under-screen fingerprint detection of the liquid crystal display, the optical fingerprint system of the electronic device 10 may further include an excitation light source for optical fingerprint detection, which may be specifically an infrared light source or a light source of non-visible light with a specific wavelength, which may be disposed under the backlight module of the liquid crystal display or an edge region under a protective cover plate of the electronic device 10, and the optical fingerprint module 130 may be disposed under the liquid crystal panel or the edge region of the protective cover plate and guided through an optical path so that fingerprint detection light may reach the optical fingerprint module 130; alternatively, the optical fingerprint module 130 may also be disposed below the backlight module, and the backlight module may be provided with holes or other optical designs to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint module 130 by making holes on the film layers such as the diffusion sheet, the brightness enhancement sheet, the reflection sheet, etc. When the optical fingerprint module 130 employs an internal light source or an external light source to provide an optical signal for fingerprint detection, the detection principle is consistent with that described above.

It should be appreciated that in particular implementations, the electronic device 10 may also include a transparent protective cover plate, which may be a glass cover plate or a sapphire cover plate, that is positioned over the display screen 120 and covers the front of the electronic device 10. Thus, in the present embodiment, the pressing of a finger against the display screen 120 actually means pressing a cover plate over the display screen 120 or a protective layer surface covering the cover plate.

Further, the electronic device 10 may further include a circuit board disposed below the optical fingerprint module 130. The optical fingerprint module 130 may be adhered to the circuit board by a back adhesive, and electrically connected to the circuit board by soldering with a pad and a metal wire. The optical fingerprint module 130 may be electrically interconnected and signal-transmitting with other peripheral circuits or other elements of the electronic device 10 through a circuit board. For example, the optical fingerprint module 130 may receive a control signal of the processing unit of the electronic device 10 through the circuit board, and may also output a fingerprint detection signal from the optical fingerprint module 130 to the processing unit or the control unit of the terminal device 10 through the circuit board, or the like.

In some implementations, the optical fingerprint module 130 may include only one optical fingerprint sensor, where the area of the fingerprint detection area 103 of the optical fingerprint module 130 is smaller and the position is fixed, so that the user needs to press the finger to a specific position of the fingerprint detection area 103 when inputting the fingerprint, otherwise, the optical fingerprint module 130 may not be able to collect the fingerprint image, resulting in poor user experience. In other alternative embodiments, the optical fingerprint module 130 may include a plurality of optical fingerprint sensors. The plurality of optical fingerprint sensors may be disposed side by side below the display screen 120 in a spliced manner, and the sensing areas of the plurality of optical fingerprint sensors together form the fingerprint detection area 103 of the optical fingerprint module 130. The fingerprint detection area 103 of the optical fingerprint module 130 can be extended to the main area of the lower half of the display screen 120, that is, to the usual finger pressing area, thereby realizing the blind press type fingerprint input operation. Further, when the number of the optical fingerprint sensors is sufficient, the fingerprint detection area 103 may also be extended to half the display area or even the whole display area, thereby realizing half-screen or full-screen fingerprint detection.

For example, as shown in fig. 3 and fig. 4, the optical fingerprint module 130 in the electronic device 10 includes a plurality of optical fingerprint sensors, where the plurality of optical fingerprint sensors may be disposed below the display screen 120 side by way of, for example, stitching, and the sensing areas of the plurality of optical fingerprint sensors together form the fingerprint detection area 103 of the optical fingerprint module 130.

Optionally, corresponding to the plurality of optical fingerprint sensors of the optical fingerprint module 130, the optical component 132 may include a plurality of light guiding layers, where each light guiding layer corresponds to one optical fingerprint sensor and is respectively attached to and disposed above the corresponding optical fingerprint sensor. Alternatively, the plurality of optical fingerprint sensors may share a unitary light guiding layer, i.e. the light guiding layer has a sufficiently large area to cover the sensing array of the plurality of optical fingerprint sensors.

In addition, the optical component 132 may further include other optical elements, such as a Filter (Filter) or other optical film, which may be disposed between the light guiding layer and the optical fingerprint sensor, or between the display 120 and the light guiding layer, to mainly isolate the influence of the external disturbance light on the optical fingerprint detection. Wherein the filter may be used to filter out ambient light that penetrates the finger and passes through the display screen 120 into the optical fingerprint sensor. Similar to the light guide layer, the optical filter may be separately provided for each optical fingerprint sensor to filter out the interference light, or a large-area optical filter may be used to cover a plurality of optical fingerprint sensors at the same time.

The light guide layer can also be replaced by an optical Lens (Lens), and a small hole can be formed above the optical Lens through a shading material and matched with the optical Lens to converge fingerprint detection light to an optical fingerprint sensor below so as to realize fingerprint imaging. Similarly, each optical fingerprint sensor may be configured with one optical lens for fingerprint imaging, or a plurality of optical fingerprint sensors may use the same optical lens for light convergence and fingerprint imaging. In other alternative embodiments, each optical fingerprint sensor may even have two sensing arrays (Dual Array) or multiple sensing arrays (Multi-Array), and two or more optical lenses are simultaneously configured to optically image in cooperation with the two or more sensing arrays, thereby reducing imaging distance and enhancing imaging effect.

When fingerprint detection is carried out, the light source irradiates the finger above the display screen, and the optical fingerprint sensor collects the light signals returned by reflection or scattering of the finger, so that fingerprint information of the finger is obtained. However, the fingerprint detection is disturbed by the red light and the infrared light. For example, when fingerprint detection is performed outdoors, red light and infrared light in sunlight can directly penetrate through a finger to reach an optical fingerprint sensor, so that light carrying fingerprint signals is annihilated in background noise of the red light and the infrared light, and the fingerprint detection is affected.

In order to reduce the influence of red light and infrared light on fingerprint detection, an infrared cut-off filter can be arranged on a light path between the display screen and the optical fingerprint sensor so as to filter the red light and the infrared light. Hereinafter, the infrared cut filter is simply referred to as an infrared filter (Infrared Radiation Cut, IRC) or an infrared filter layer. For example, the infrared filter may cut red light and infrared light in a wavelength band above its cut-off wavelength, and reduce the interference of the red light and infrared light with useful fingerprint detection signals by reflecting the red light and infrared light outward to reduce the incidence of the red light and infrared light into the optical fingerprint sensor.

The external infrared filter layer can cause the increase of the thickness of the optical fingerprint module, and the appearance of the display screen can be influenced under strong light. For this purpose, a built-in infrared filter layer may be used. However, the built-in infrared filter layer has no external infrared filter layer with good cut-off characteristics in the red and infrared bands. For example, as shown in fig. 5, the transmittance of the internal infrared filter layer for red light and infrared light is significantly higher than that of the external infrared filter layer. This can make the sensing unit of the optical fingerprint sensor susceptible to saturation. In this case, in order to avoid the glare problem, the cut-off wavelength of the infrared filter layer can be reduced only, for example, from 615 nm to 605 nm.

However, lowering the cut-off wavelength of the infrared filter results in a significant reduction of the red light component entering the optical fingerprint sensor. When fingerprint anti-counterfeiting is performed by utilizing the color filter layer, the red light component is reduced, so that the anti-counterfeiting performance of the fingerprint anti-counterfeiting device is possibly reduced, and meanwhile, the drift and fluctuation of the red light component along with temperature are increased.

On the other hand, when strong light detection is needed, the reduction of the red light component can also lead some fingerprint images to not accurately extract strong light marks, but the image characteristics are interfered by strong light, so that image signals and the like deviate from a normal interval, and the difficulties of fingerprint image detection and fingerprint anti-counterfeiting are increased.

Therefore, the embodiment of the application provides a fingerprint detection device, which effectively realizes the function of an infrared filter layer and cannot influence fingerprint anti-counterfeiting and strong light detection.

Fig. 6 is a schematic block diagram of an apparatus for fingerprint detection according to an embodiment of the present application. The fingerprint detection device is arranged below the display screen and used for detecting fingerprints under the screen. As shown in fig. 6, the fingerprint detection device 600 includes a color filter layer 610, an infrared filter layer 620, and an optical fingerprint sensor 630.

The embodiment of the application provides two modes of the device 600, which can improve the anti-counterfeiting performance and/or the strong light detection performance of fingerprints while realizing the function of the infrared filter layer. The following description is made separately.

Mode 1

The color filter layer 610 includes a plurality of sets of color filter units 611, wherein each set of color filter units 611 includes a red filter unit for transmitting red light signals returned from the finger.

The infrared filter 620 is used to block red light and infrared light above its cut-off wavelength. Wherein, an opening is disposed in the infrared filter 620 at a position corresponding to the red filter unit, so as not to block the red light signal passing through the red filter unit.

The optical fingerprint sensor 630 is used to detect the optical signal of the finger that returns to and passes through the color filter layer 610 and the infrared filter layer 620, which is used to acquire the fingerprint image of the finger. Wherein, the red light signal in the light signal is used for determining the authenticity of the finger and/or for strong light detection.

In this embodiment, the infrared filter layer 620 can block the red light and the infrared light above the cut-off wavelength to avoid the influence of the infrared light and the red light on the fingerprint detection, and the red filter unit in the color filter layer 610 can transmit the red light signal for the identification of the fingerprint authenticity. Because the infrared filter layer 630 is provided with the opening at the position corresponding to the red filter unit, the red signal transmitted through the red filter unit is prevented from being blocked, so that the function of the infrared filter layer 620 is effectively realized, and meanwhile, the transmitted red signal can be utilized to judge the authenticity of the finger and/or detect the strong light.

Therefore, the cut-off wavelength of the infrared filter layer can be set lower, and the influence on fingerprint anti-counterfeiting and strong light detection is avoided.

It should be appreciated that the apparatus 600 for fingerprint detection may correspond to the optical fingerprint module 130 described above, and reference may be made to the description of the optical fingerprint module 130 for further details of the apparatus 600.

The color filter layer 610 is also called a Color Filter (CF), and is used for discriminating the authenticity of the finger. Because the fake fingerprint made of silica gel and other materials has large difference with the fingerprint of the true finger in terms of material, spectral characteristics, internal optical scattering and the like, the authenticity of the fingerprint can be judged by fingerprint detection. For example, the transmittance of a fake fingerprint to different color light signals may be equal, while there is a significant difference between the transmittance of a real fingerprint to different color light signals; for another example, the transmittance of a fake fingerprint for a light signal of a certain color is significantly different from the transmittance of a true fingerprint for a light signal of that color.

In addition to the red filter units, further, each group of color filter units 611 in the color filter layer 610 may further include filter units of other colors, for example, a green filter unit, a blue filter unit, and the like.

The plurality of sets of color filter units 611 in the color filter layer 610 may be arranged in a certain manner, for example, as shown in fig. 7, and the plurality of sets of color filter units 611 are distributed in an array in the color filter layer 610.

Each group of color filter units 611 in the color filter layer 610 shown in fig. 7 includes a red filter unit (R), a green filter unit (G), and a blue filter unit (B).

For the different color filter units in each group of color filter units 611, the filter units may be arranged in a certain manner to form a specific pattern (pattern). For example, as shown in fig. 7, the red filter units, the green filter units, and the blue filter units in each group of filter units 611 are alternately arranged, and a certain interval may exist between adjacent filter units.

The red filter unit, the green filter unit and the blue filter unit can transmit red light signals, green light signals and blue light signals respectively. The green light signal and the blue light signal can reach the optical fingerprint sensor and are used for fingerprint anti-counterfeiting because the green light signal and the blue light signal are not blocked by the infrared filter layer. And an opening is provided in the infrared filter 620 at a position corresponding to the red filter unit, so that the red light signal can reach the optical fingerprint sensor 630 through the opening. In this way, the optical fingerprint sensor 630 can obtain enough red light signals for fingerprint anti-counterfeiting and strong light detection.

The areas 612 of fig. 7 other than the red, green, and blue filter elements are substrates of the color filter layer 610, which may be transparent or green, for example. The light signal transmitted through region 612, upon reaching the fingerprint sensor, may be used to acquire a fingerprint image. Thus, when the fingerprint image is acquired by utilizing the light signals transmitted by the area 612, fingerprint anti-counterfeiting is realized by utilizing the light signals transmitted by the red light filtering unit, the green light filtering unit and the blue light filtering unit, and the security of fingerprint detection is improved.

Since the red filter units in each group of color filter units 611 can transmit more red light components, the color filter units can also be used for strong light detection. In strong light environments, such as outdoor sunlight environments, the user has more red light signals when performing fingerprint detection, and has less red light signals in indoor or darker environments. The fingerprint image processing device can judge whether the current user is in a strong light environment according to the intensity of the red light signal detected by the optical fingerprint sensor, and adjust the fingerprint algorithm when the current user is in the strong light environment so as to process other light signals detected by the optical fingerprint sensor, thereby obtaining more accurate fingerprint images.

It can be seen that, in the mode 1, by providing the opening on the infrared filter layer 620, the red light component in the optical signal that the finger returns to and can reach the optical fingerprint sensor 630 is increased, and the increased red light component can be used for strong light detection and fingerprint anti-counterfeiting.

The color filter layer 610 shown in fig. 7 is only an example, and in practical applications, each group of color filter units 611 of the color filter layer 610 may further include one or more other colors. For example, each group of color filter units 611 in the color filter layer 610 includes a red filter unit and a blue filter unit, which transmit red light signals and blue light signals for fingerprint security, and the region 612 is green or transparent.

The color filter units 611 of each group may have other distribution patterns on the color filter layer 610, for example, each group of color filter units 611 forms a circular array, a diamond array, or the like on the color filter layer 610.

Fig. 8 is an example of another color filter layer 610. In fig. 8, a plurality of sets of color filter units 611 are distributed in an edge area of the color filter layer 610. In this way, only the openings corresponding to the red filter units need to be formed on the edge of the infrared filter layer 620, thereby reducing the process complexity of the infrared filter layer 620.

The optical fingerprint sensor 630 in this embodiment includes a plurality of optical sensing units, each red filtering unit in the color filtering layer corresponds to one or more optical sensing units, and the one or more optical sensing units are used for detecting red light signals transmitted by the corresponding red filtering unit.

For example, in fig. 7 and 8, each filter unit in each set of color filter units 611 corresponds to a different optical sensing unit. The optical sensing unit corresponding to the red filtering unit is used for detecting a red light signal transmitted by the red filtering unit, the optical sensing unit corresponding to the green filtering unit is used for detecting a green light signal transmitted by the green filtering unit, and the optical sensing unit corresponding to the blue filtering unit is used for detecting a blue light signal transmitted by the blue filtering unit. These signals are used for discriminating the authenticity of the fingerprint and/or for strong light detection. And each optical sensing unit corresponding to the region 612 is used for detecting the optical signals transmitted by the region 612, and the optical signals are used for acquiring the fingerprint image.

Mode 2

The color filter layer 610 includes a plurality of red filter units located at an edge region of the color filter layer 610, and the red filter units are used for transmitting red light signals returned by the finger.

The infrared filter 620 is used to block red light and infrared light above its cut-off wavelength. Wherein the area of the infrared filter 620 is smaller than that of the color filter 610 so as not to block the red light signal passing through the red filter unit of the edge region.

The optical fingerprint sensor 630 is used to detect the optical signal of the finger that returns to and passes through the color filter layer 610 and the infrared filter layer 620, which is used to acquire the fingerprint image of the finger. The red light signal transmitted through the red filter unit in the edge area is used for strong light detection.

In this embodiment, the infrared filter layer 620 can block the red light and the infrared light above the cut-off wavelength to avoid the influence of the infrared light and the red light on fingerprint detection, and the red filter unit in the color filter layer 610 is used for transmitting the red light signal for strong light detection. Since the area of the infrared filter layer 630 is set smaller than that of the color filter layer 610, and the edge region of the color filter layer 610 is provided with a red filter unit. In this way, the infrared filter layer 630 will not block the red light signal transmitted by the red filter unit in the edge area, so that the red light signal transmitted by the red filter unit can be used for strong light detection while the function of the infrared filter layer 620 is effectively realized.

Taking the color filter layer 610 shown in fig. 9 as an example, the edge region in the color filter layer 610 is provided with a red filter unit 611. Each of the red filter units 611 shown in fig. 9 may transmit red light signals, and since the area of the infrared filter layer 620 is smaller than that of the color filter layer 610, the red light is not blocked by the infrared filter layer 620, so that the optical fingerprint sensor 630 acquires a sufficient red light component and is used for strong light detection. The other region 612 than the red filter unit 611 is a substrate of the color filter layer 610, which may be transparent or green, for example. After the transmitted light signal reaches the fingerprint sensor, the area 612 can be used to acquire a fingerprint image. In this way, the optical signal transmitted by the region 612 is used to acquire the fingerprint image, and the optical signal transmitted by the red filter unit is used to realize strong light detection.

In addition to the red filter unit, the edge region of the color filter layer 610 may be provided with filter units of other colors, such as a green filter unit, a blue filter unit, and the like.

When only the red filter unit is present at the edge area of the color filter layer 610, the transmitted red signal can be used for strong light detection, but the fingerprint anti-counterfeiting effect based on the red signal is not optimal. For this purpose, a plurality of color filter units can be arranged in the edge area to increase the fingerprint anti-counterfeiting function.

For example, as shown in fig. 9, the edge region of the color filter layer 610 is provided with red filter units, green filter units, and blue filter units alternately arranged. The infrared filter 620 has an area smaller than the area 610 of the color filter 610 so as not to block the light signal transmitted through the edge region of the color filter 610. The red filter unit, the green filter unit and the blue filter unit in the edge area can transmit red light signals, green light signals and blue light signals respectively. Since the area of the infrared filter layer 620 is smaller than that of the color filter layer 610, the infrared filter layer 620 does not block the red light signal transmitted by the color filter layer 610, so that the red light signal can reach the optical fingerprint sensor together with the green light signal and the blue light signal, thereby realizing strong light detection and fingerprint anti-counterfeiting. And the transmitted light signal from region 612, after reaching the fingerprint sensor, can be used to acquire a fingerprint image. Thus, the strong light detection and fingerprint anti-counterfeiting are realized while the fingerprint image is formed.

In this embodiment, the middle region of the color filter layer 620 may be a substrate, such as a transparent substrate. Alternatively, the middle area of the color filter layer 620 may be provided with a plurality of sets of color filter units 611 as shown in fig. 7 or 8, where the red filter units of the edge area are used for strong light detection, and the color filter units of the middle area are used for fingerprint security. At this time, the position of the infrared filter 620 corresponding to the red filter unit may not be perforated, so as to reduce the complexity of the process of the infrared filter 620, but may sacrifice the anti-counterfeit performance of the fingerprint.

The relative sizes of the middle region and the edge region are not limited in the embodiments of the present application. The edge region is located outside the middle region, wherein the edge region of the color filter layer 610 corresponds to an optical sensing unit located at an edge of the optical fingerprint sensor 630, and the middle region corresponds to an optical sensing unit located in the middle of the optical fingerprint sensor 630. In particular, the filter element of the edge region may correspond to at least one turn of the optical sensing element of the edge of the optical fingerprint sensor, for example one, two or three turns of the optical sensing element.

Also, one or more black filter units may be disposed around the color filter layer 610 to absorb the light signal returned from the finger. The one or more turns of black filter elements may correspond to one or more turns of optical sensing elements of an edge of the optical fingerprint sensor. The optical signals collected by the optical sensing units corresponding to the black filtering units are noise signals, and the optical signals collected by other sensing units can be subjected to noise cancellation and other processing according to the noise signals, so that the influence of noise on fingerprint detection is reduced.

It can be seen that, in mode 2, by setting the area of the infrared filter 620 smaller than that of the color filter 610, the red light signal transmitted through the red filter unit at the edge of the color filter 610 is not blocked, so that the red light component in the light signal returned by the finger is increased, and the increased red light component can be used for strong light detection.

For example, in fig. 8, each red filter unit on the edge area of the color filter layer 610 corresponds to a different optical sensing unit, and each optical sensing unit can detect the red light signal transmitted by its corresponding red filter unit. And each optical sensing unit corresponding to the middle region 612 is used for detecting the optical signal transmitted by the region 612.

In the embodiment of the present application, the apparatus 600 for fingerprint detection may further include an optical path guiding structure.

Wherein the light path guiding structure 640 includes a microlens array 641 having a plurality of microlenses, and at least one light blocking layer. Wherein each light blocking layer is provided with a plurality of openings corresponding to the microlenses respectively.

The micro-lens is used to collect the optical signal returned by the finger to the corresponding opening in the light blocking layer and transmit the optical signal to the optical fingerprint sensor 630 through the corresponding opening in the light blocking layer.

Alternatively, in one implementation, the color filter layer 610 described above may be located below the microlens array 641.

Alternatively, in one implementation, when the light path guiding structure 640 includes two light blocking layers, the infrared filter layer 620 described above may be disposed between the two light blocking layers.

Alternatively, in one implementation, the first light blocking layer 642 of the bottom layer of the two light blocking layers is integrated with the optical fingerprint sensor 630. For example, a top metal layer in the optical fingerprint sensor 630 may be used as the first light blocking layer 642, such that the first light blocking layer 642 becomes part of the optical fingerprint sensor 630, and may be, for example, a wire connection layer of the optical fingerprint sensor 630.

Further, the infrared filter layer 620 may be disposed over the first light blocking layer 642. For example, the first light blocking layer 642 and the infrared filter layer 620 may be connected through the transparent dielectric layer 634, and the infrared filter layer 620 may be formed on the upper surface of the transparent dielectric layer 634 by a plating method.

When the metal layer of the top layer in the optical fingerprint sensor 630 is used as the first light blocking layer 642, the transparent dielectric layer 634 may also cover the upper surface of the first light blocking layer 642 as part of the optical fingerprint sensor 630 and fill the openings in the first light blocking layer 642. The transparent dielectric layer 634 may be used, for example, as a protective function for protecting the optical fingerprint sensor 630.

Further, a second light blocking layer 643 of the two light blocking layers may be disposed between the color filter layer 610 and the infrared filter layer 620.

Referring to the apparatus 600 for fingerprint detection shown in fig. 10, the apparatus 600 is disposed below the display 650. The device 600 includes, in order from top to bottom, a microlens array 641, a color filter layer 610, a second light blocking layer 643, an infrared filter layer 620, a first light blocking layer 642, and an optical fingerprint sensor 630. The color filter layer 610 includes a red filter unit 6111, a green filter unit 6112, and a blue filter unit 6113, where it is assumed that there is no space between the red filter unit 6111, the green filter unit 6112, and the blue filter unit 6113. The infrared filter 620 is provided with an opening B at a position corresponding to the red filter unit 6111. The microlens array 641 includes a plurality of microlenses, for example, microlenses 6411 to 6413. The optical fingerprint sensor 630 includes a plurality of optical sensing units, for example, optical sensing units 631 to 633.

After passing through the micro lens 6411, the optical signal returned by the finger reaches the red filtering unit 6111 in the color filtering layer 610, and the red filtering unit 6111 filters the optical signal to obtain a red light signal. The red light signal passes through the opening a on the second light blocking layer 643, the opening B in the infrared filter layer 620, and the opening C on the first light blocking layer 642 in sequence, and finally reaches the optical sensing unit 631; similarly, the light signal converged by the micro lens 6412 reaches the green filter unit 6112 in the color filter layer 610 to obtain a green light signal, and the green light signal sequentially passes through the corresponding opening on the second light blocking layer 643, the infrared filter layer 620, and the corresponding opening on the first light blocking layer 642 to reach the optical sensing unit 632; the light signal converged by the micro lens 6413 reaches the blue filter unit 6113 in the color filter layer 610 to obtain a blue light signal, and the blue light signal sequentially passes through the corresponding opening on the second light blocking layer 643, the infrared filter layer 620, and the corresponding opening on the first light blocking layer 642 to reach the optical sensing unit 633.

Since the infrared filter layer 620 blocks only red light and infrared light, blue light and green light are not blocked. Accordingly, in the infrared filter layer 620, an opening may be provided only at a position corresponding to the red filter unit 6111. Of course, if openings are also provided in the infrared filter layer 620 at positions corresponding to the green filter unit 6112 and the blue filter unit 6113, it is not impossible.

The red component of the optical signals collected by the optical sensing units 631, 632 and 633 is used for fingerprint anti-counterfeiting and/or strong light detection. Whether the fingerprint image is derived from a living finger can be discriminated based on fingerprint forgery prevention. And based on the result of strong light detection, the fingerprint image can be corrected, so that the accurate fingerprint image can be obtained under the strong light environment.

Alternatively, in fig. 10, the aperture of the aperture a in the second light blocking layer 643, the aperture B in the infrared filter layer, and the aperture C in the first light blocking layer 642 may be set to decrease in order from top to bottom. This allows light signals within a certain angular range to be directed to the corresponding optical sensing unit.

When the finger shown in fig. 10 contacts the upper surface of the display screen 350, an area partially covered by the finger and an area fully covered by the finger are formed. For the area where the finger is fully covered, the intensity of the optical signal that can be obtained by the optical fingerprint sensor 630 is generally small and thus unsuitable for use as strong light detection. In the embodiment of the present application, since the infrared filter layer 620 does not block the light signal transmitted by the red filter unit in the color filter layer 610, the optical sensing unit corresponding to the red filter unit can obtain enough red light signal, and the light signal returned by the area covered by the finger can also be used for strong light detection. For the area covered by the finger part, the optical fingerprint sensor 630 can have more strong light components, so that the judgment of the pressing position of the finger can be assisted, and the subsequent execution of the fingerprint algorithm is convenient.

Fig. 10 shows the optical path for fingerprint detection using a tilted optical path. However, the embodiment of the present application may also use a perpendicular light path for fingerprint detection, such as shown in fig. 11. Details of the respective structures in fig. 11 may refer to the descriptions in fig. 11, and are not repeated here for brevity.

The embodiment of the application also provides an electronic device, which comprises the fingerprint detection device 600 in the various embodiments of the application.

The electronic device may also comprise a display screen, which may be for example a conventional non-folding display screen, or a foldable display screen, or a so-called flexible display screen.

By way of example, and not limitation, the electronic device in the embodiments of the present application may be a portable or mobile computing device such as a terminal device, a mobile phone, a tablet computer, a notebook computer, a desktop computer, a game device, an in-vehicle electronic device, or a wearable smart device, and other electronic devices such as an electronic database, an automobile, and a bank automated teller machine (Automated Teller Machine, ATM). The wearable intelligent device comprises devices which are full in function, large in size and capable of achieving complete or partial functions independently of a smart phone, such as a smart watch or smart glasses, and devices which are only focused on certain application functions and are required to be matched with other devices such as the smart phone, such as various types of smart bracelets, smart jewelry and the like for physical sign monitoring.

It should be noted that, on the premise of no conflict, the embodiments described in the present application and/or the technical features in the embodiments may be arbitrarily combined with each other, and the technical solutions obtained after the combination should also fall into the protection scope of the present application.

It should be understood that the specific examples in the embodiments of the present application are only for helping those skilled in the art to better understand the embodiments of the present application, and not limit the scope of the embodiments of the present application, and those skilled in the art may make various improvements and modifications based on the above embodiments, and these improvements or modifications fall within the protection scope of the present application.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An apparatus for fingerprint detection disposed below a display screen of an electronic device for off-screen fingerprint detection, the apparatus comprising:

the optical fingerprint sensor is used for detecting optical signals returned by the finger and transmitted through the color filter layer and the infrared filter layer, wherein the optical signals are used for acquiring fingerprint images of the finger, and the red light signals in the optical signals are used for determining authenticity of the finger and/or used for strong light detection;

the red light signals transmitted by the red light filter units positioned in the edge area of the color filter layer in the multiple groups of color filter units are used for determining the authenticity of the finger, and the red light signals transmitted by the red light filter units positioned in the middle area of the color filter layer are used for strong light detection;

the optical fingerprint sensor comprises a plurality of optical sensing units, each red filtering unit in the color filtering layer corresponds to one or more optical sensing units, and the one or more optical sensing units are used for detecting red light signals transmitted through the corresponding red filtering units.

2. The apparatus of claim 1, wherein each set of color filter units further comprises a green filter unit and/or a blue filter unit.

3. The apparatus of claim 1 or 2, wherein the plurality of sets of color filter units are distributed in an array over the color filter layer.

4. The device according to claim 1 or 2, wherein the infrared filter layer is provided with openings at positions corresponding to the red filter units of the edge region, and wherein the infrared filter layer is provided with or without openings at positions corresponding to the red filter units of the intermediate region.

5. The device according to claim 1 or 2, wherein the plurality of sets of color filter units are distributed in an edge region of the color filter layer.

6. The device of claim 5, wherein the filter elements of the edge region may correspond to at least one turn of optical sensing elements of an edge of the optical fingerprint sensor.

7. The apparatus of claim 1 or 2, further comprising an optical path guiding structure comprising:

a microlens array including a plurality of microlenses;

8. The device of claim 7, wherein the color filter layer is positioned below the microlens array and the infrared filter layer is positioned between two light blocking layers.

9. The apparatus of claim 8, wherein a first light blocking layer of the at least one light blocking layer is integrated with the optical fingerprint sensor, the infrared filter layer disposed over the first light blocking layer.

10. The device according to claim 9, wherein the first light blocking layer is connected to the infrared filter layer through a transparent dielectric layer, and the infrared filter layer is formed on the upper surface of the transparent dielectric layer through a film plating method.

11. The device of claim 10, wherein a second light blocking layer of the at least one light blocking layer is located between the color filter layer and the infrared filter layer.

12. The device according to claim 11, wherein the aperture of the opening in the second light-blocking layer, the opening in the infrared filter layer, and the opening in the first light-blocking layer decrease in order from top to bottom.

13. The device according to claim 1 or 2, wherein the optical signal returned by the finger is a vertical optical signal or a tilted optical signal.

14. An apparatus for fingerprint detection disposed below a display screen of an electronic device for off-screen fingerprint detection, the apparatus comprising:

the optical fingerprint sensor is used for detecting optical signals which are returned by the finger and penetrate through the color filter layer and the infrared filter layer, the optical signals are used for acquiring fingerprint images of the finger, and the red light signals which penetrate through the red filter unit in the edge area in the optical signals are used for strong light detection;

The color filter layer further comprises a plurality of groups of color filter units positioned in the middle area of the color filter layer, wherein each group of color filter units comprises a red filter unit, and the red filter unit is used for transmitting red light signals returned by fingers;

an opening is formed in the infrared filter layer at a position corresponding to the red filter unit in the middle area, the opening in the infrared filter layer is used for transmitting the red light signal, and the red light signal transmitted through the red filter unit in the middle area in the optical signal is used for fingerprint anti-counterfeiting;

the fingerprint sensor comprises a plurality of optical sensing units, each red filtering unit in the color filtering layer corresponds to one or more optical sensing units, and the one or more optical sensing units are used for detecting red light signals transmitted through the corresponding red filtering units.

15. The apparatus of claim 14, wherein each set of color filter units further comprises a blue filter unit and/or a green filter unit.

16. The apparatus of claim 14 or 15, further comprising an optical path guiding structure comprising:

A microlens array including a plurality of microlenses;

17. The device of claim 16, wherein the color filter layer is positioned below the microlens array and the infrared filter layer is positioned between two light blocking layers.

18. The apparatus of claim 17, wherein a first light blocking layer of the at least one light blocking layer is integrated with the optical fingerprint sensor, the infrared filter layer disposed over the first light blocking layer.

19. The device of claim 18, wherein the first light blocking layer is connected to the infrared filter layer through a transparent dielectric layer, and the infrared filter layer is formed on an upper surface of the transparent dielectric layer through a coating method.

20. The device of claim 19, wherein a second light blocking layer of the at least one light blocking layer is located between the color filter layer and the infrared filter layer.

21. The device according to claim 20, wherein the aperture of the opening in the second light-blocking layer, the opening in the infrared filter layer, and the opening in the first light-blocking layer decrease in order from top to bottom.

22. The device of claim 14 or 15, wherein the optical signal returned by the finger is a vertical optical signal or a tilted optical signal.

23. An electronic device comprising the apparatus for fingerprint detection according to any one of claims 14 to 22.