CN111801679B

CN111801679B - Fingerprint detection device and electronic equipment

Info

Publication number: CN111801679B
Application number: CN201980013671.2A
Authority: CN
Inventors: 王胤; 张思超; 林峻贤; 蔡斐欣
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2019-07-12
Filing date: 2019-12-27
Publication date: 2024-04-30
Anticipated expiration: 2039-12-27
Also published as: CN111801679A

Abstract

The utility model provides a fingerprint detection device and electronic equipment, fingerprint detection device is array distribution or crisscross a plurality of fingerprint detection units that set up, and every fingerprint detection unit includes: the fingerprint sensor comprises at least one micro lens, at least one light blocking layer below the at least one micro lens and a plurality of optical sensing pixels below the at least one light blocking layer, wherein oblique optical signals in 2M directions reflected by a finger above the display screen are converged by the at least one micro lens and then are respectively transmitted to the plurality of optical sensing pixels through openings arranged in the at least one light blocking layer, the oblique optical signals are used for detecting fingerprint information of the finger, and M is a positive integer. Through receiving the slope light signal on 2M directions, not only can be on the basis that promotes dry finger fingerprint identification effect, can also reduce the thickness of optical fingerprint module.

Description

Fingerprint detection device and electronic equipment

The application claims priority from the following applications, the entire contents of which are incorporated in the application by application:

2019-07-12 filed PCT application by the chinese patent office with application number PCT/CN2019/095780, entitled "apparatus for fingerprint detection and electronic device";

2019-07-12 filed PCT application by the chinese patent office with application number PCT/CN2019/095880, entitled "fingerprint detection device and electronic equipment";

2019-08-02 filed PCT application by the chinese patent office with application number PCT/CN2019/099135 entitled "fingerprint detection device and electronic equipment"; and

2019-09-26 Filed PCT application by the chinese patent office with application number PCT/CN2019/108223, entitled "fingerprint detection device and electronic apparatus".

Technical Field

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

Background

Due to the increasing miniaturization of future handheld electronic products, the size of the existing lens type under-screen optical fingerprint products is difficult to adapt to the trend, and the development of the lens type under-screen optical fingerprint products is urgently required to be towards the directions of thinner thickness, smaller size and higher integration degree. In the existing miniaturization scheme, the image contrast of the collimation hole imaging is related to the depth of the collimation hole, and a relatively large depth is needed to achieve relatively high imaging quality, and meanwhile, the light utilization rate of the scheme is relatively low. The scheme of utilizing micro lens focusing is limited by the process and lens surface shape, although the light utilization rate is higher, the light path design is more complex, and the design parameters with normalization are lacking, so that the optical signals at different positions are easy to be aliased, the signal contrast is lower, and the imaging quality of fingerprints is not high.

Disclosure of Invention

The fingerprint detection device and the electronic equipment are provided, and the thickness of the optical fingerprint module can be reduced on the basis of improving the fingerprint identification effect of the dry finger.

In a first aspect, a fingerprint detection device is provided, and below being applicable to the display screen is in order to realize the optical fingerprint detection under the screen, fingerprint detection device is including being array distribution or crisscross a plurality of fingerprint detection units that set up, every fingerprint detection unit in a plurality of fingerprint detection units includes:

a plurality of photo-sensing pixels;

At least one microlens disposed over the plurality of photo-sensing pixels;

The light blocking layers are arranged between the at least one micro lens and the plurality of optical sensing pixels, and openings corresponding to the plurality of optical sensing pixels are formed in each light blocking layer;

And after the inclined optical signals in 2M directions reflected by the finger above the display screen are converged by the at least one micro lens, the inclined optical signals are respectively transmitted to the plurality of optical sensing pixels through the holes arranged in the at least one light blocking layer, the inclined optical signals are used for detecting fingerprint information of the finger, and M is a positive integer.

Oblique light signals in 2M directions reflected from a finger above the display screen are converged by the one microlens and then respectively transmitted to the plurality of optical sensing pixels through the openings arranged in the at least one light blocking layer, the exposure time of the optical sensing pixels, the thickness and the cost of the fingerprint detection device can be reduced, the robustness, tolerance, angle of view and field of view of the fingerprint detection device can be improved, and further fingerprint recognition effects, particularly those of dry fingers, are improved.

In addition, the center position of the photosensitive area of each of the plurality of optical sensing pixels is shifted from the center position of the same optical sensing pixel, so that the image distance of the one microlens can be further increased under the condition that the vertical distance between the one microlens and the plurality of optical sensing pixels is fixed, and the thickness of the fingerprint detection device can be further reduced.

Moreover, the structural complexity of the fingerprint detection unit can be simplified by symmetrically designing the 2M-direction oblique optical signals. For example, the complexity of the optical path design of at least one light blocking layer in the fingerprint detection unit can be simplified.

In some possible implementations, the 2M directions include a first direction and a second direction, a projection of the first direction on the display screen being perpendicular to a projection of the second direction on the display screen.

In some possible implementations, the projection of the first direction or the second direction on the display screen is perpendicular to the polarization direction of the display screen.

Through receiving the oblique light signal perpendicular to the polarization direction of display screen, can guarantee the receipts light direction of fingerprint detection unit is including the best receipts light direction that is used for fingerprint identification, and then increases the signal quantity of the light signal that fingerprint detection unit received to guarantee fingerprint identification effect.

In some possible implementations, the plurality of photo-sensing pixels form a rectangular array of photo-sensing pixels, and a projection of the first direction or the second direction onto the rectangular array of photo-sensing pixels is parallel to a diagonal direction of the rectangular array of photo-sensing pixels.

The first direction is designed to be parallel to the diagonal direction of the rectangular array of optical sensing pixels, so that the light spot area of the optical sensing pixels can move in the direction of the diagonal, the offset tolerance of the light plate area can be increased, and the pixel arrangement mode of the optical sensing pixels can be rationally designed aiming at oblique light signals.

In some possible implementations, the at least one microlens is one microlens, the plurality of optical sensing pixels is a first column of optical sensing pixels in a 2x2 optical sensing pixel matrix array, the one microlens is located above a center position of the 2x2 optical sensing pixel matrix array, and a second column of optical sensing pixels of the 2x2 optical sensing pixel matrix array is multiplexed to optical sensing pixels in the first column of optical sensing pixels in other fingerprint detection units.

The micro-lens is used for converging the light signals in two directions to the two optical sensing pixels, so that the design complexity of the fingerprint detection unit can be effectively simplified.

In some possible implementations, two fingerprint detection units in the fingerprint detection device that are adjacent in the row direction of the 2x2 matrix of optically sensitive pixels are offset by one optically sensitive pixel in the arrangement direction of the first column of optically sensitive pixels in the 2x2 matrix of optically sensitive pixels.

By dislocating one optical sensing pixel, the occupied space of the fingerprint detection unit can be saved, so that the size of the fingerprint detection unit is reduced.

In some possible implementations, the at least one microlens is one microlens, the plurality of optical sensing pixels are a first row first column optical sensing pixel and a fourth row first column optical sensing pixel of a first column optical sensing pixel in the 4x2 optical sensing pixel matrix array, the one microlens is located above a center position of a second column optical sensing pixel in the 4x2 optical sensing pixel matrix array, which is far from a side length of the first column optical sensing pixel, and optical sensing pixels in the 4x2 optical sensing pixel matrix array except for the first row first column optical sensing pixel and the fourth column optical sensing pixel are multiplexed into optical sensing pixels in other fingerprint detection units.

In addition, by increasing the length of the path between the microlens and the optical sensing pixel for transmitting the optical signal, the thickness of the fingerprint detection unit can be reduced.

In some possible implementations, two fingerprint detection units in the fingerprint detection device that are adjacent in the row direction of the 4x2 matrix of optically sensitive pixels are offset by one optically sensitive pixel in the arrangement direction of the first column of optically sensitive pixels in the 4x2 matrix of optically sensitive pixels.

By dislocating one optical sensing pixel, the occupied space of the fingerprint detection unit can be saved, so that the size of the fingerprint detection unit is reduced. In addition, fingerprint recognition effects of the same effect can be achieved with fewer microlenses as much as possible.

In some possible implementations, the plurality of photo-sensing pixels is a rectangular array of 4x4 photo-sensing pixels, the rectangular array of 4x4 photo-sensing pixels comprising 4 rectangular arrays of 2x2 photo-sensing pixels distributed in an array, wherein, the first column, the first row, the second row and the second column of the 4x4 optical sensing pixel rectangular array are used for receiving oblique light signals in one direction, and the first column, the second row and the first column of the 4x4 optical sensing pixel rectangular array are used for receiving oblique light signals in the other direction, and the first column, the second row and the first column of the 2x2 optical sensing pixel rectangular array are used for receiving oblique light signals in the other direction.

In some possible implementations, the at least one microlens includes one rectangular 3x2 microlens array and two rectangular 2x2 microlens arrays, the rectangular 3x2 microlens arrays are located above the first to third columns of the rectangular 4x4 photo-sensing pixel arrays, the two rectangular 2x2 microlens arrays are located above the first and fourth rows of the rectangular 4x4 photo-sensing pixel arrays, respectively, the four microlenses of each rectangular 2x2 microlens array of the two rectangular 2x2 microlens arrays are located above the four corners of the corresponding photo-sensing pixel array, such that the first row 2x2 photo-sensing pixel rectangular array and the second row 2x2 photo-sensing pixel rectangular array of the rectangular 4x4 photo-sensing pixel array receive a diagonal light signal of the rectangular 4x4 photo-sensing pixel array, and the second row 2x2 photo-sensing pixel array receives a diagonal light signal of the rectangular 4x 2 photo-sensing pixel array and the second row 2 photo-sensing pixel array of the rectangular 4x 2 photo-sensing pixel array receives a diagonal light signal of the rectangular 4x 2 photo-sensing pixel array.

In some possible implementations, the microlenses in the two 2x2 rectangular arrays of microlenses that are above the sides of the 4x4 rectangular array of optically sensitive pixels are multiplexed into microlenses in other fingerprint detection units.

In some possible implementations, each of the rectangular arrays of 4x4 photo-sensing pixels is configured to receive the light signal converged by the microlens over an adjacent photo-sensing pixel such that a first column, a first row, a second column, a second row, a rectangular array of 2x2 photo-sensing pixels in the rectangular array of 4x4 photo-sensing pixels receive a tilted light signal in a direction in which one side of the rectangular array of 4x4 photo-sensing pixels is located, and the first column second row 2x2 rectangular array of optical sensing pixels in the 4x4 rectangular array of optical sensing pixels receive oblique optical signals in the direction of the other side length adjacent to the one side length.

In some possible implementations, a microlens of the at least one microlens that is located above an outer region of the rectangular array of 4x4 optically sensitive pixels is multiplexed into a microlens of the other fingerprint detection units.

In some possible implementations, the plurality of photo-sensing pixels are a plurality of rows of photo-sensing pixels, at least one row of first photo-sensing pixels in the plurality of rows of photo-sensing pixels being configured to receive oblique light signals in one direction, and at least one row of second photo-sensing pixels in the plurality of rows of photo-sensing pixels being configured to receive oblique light signals in another direction.

In some possible implementations, each of the plurality of rows of photo-sensing pixels is configured to receive the light signals converged by the microlenses over adjacent photo-sensing pixels such that the at least one row of first photo-sensing pixels receives oblique light signals along an arrangement direction of the photo-sensing pixels and the at least one row of second photo-sensing pixels receives oblique light signals along a direction perpendicular to the arrangement direction of the photo-sensing pixels.

In some possible implementations, the at least one microlens is a rectangular array of 3x1 microlenses, the plurality of optical sensing pixels is a first column of optical sensing pixels in a rectangular array of 4x2 optical sensing pixels, the rectangular array of 3x1 microlenses is located above the rectangular array of 4x2 optical sensing pixels, and a second column of optical sensing pixels in the rectangular array of 4x2 optical sensing pixels is multiplexed to optical sensing pixels in other fingerprint detection units.

In some possible implementations, the at least one light blocking layer is a multi-layer light blocking layer, and a bottom light blocking layer of the multi-layer light blocking layer is provided with a plurality of openings respectively corresponding to the plurality of optical sensing pixels, so that the at least one microlens respectively converges the oblique optical signals in the 2M directions to the plurality of optical sensing pixels through the plurality of openings.

In some possible implementations, the openings corresponding to the same optical sensing pixel in the multi-layer light blocking layer sequentially decrease from top to bottom.

In some possible implementations, a top light blocking layer of the multi-layer light blocking layer is provided with at least one aperture corresponding to the plurality of optically sensitive pixels.

In some possible implementations, the at least one light blocking layer is a light blocking layer, and the light blocking layer is provided with a plurality of inclined holes corresponding to the plurality of optical sensing pixels, respectively, so that the at least one microlens converges the inclined light signals in the 2M directions to the plurality of optical sensing pixels through the plurality of openings, respectively.

In some possible implementations, the thickness of the light blocking layer is greater than or equal to a preset thickness, so that the plurality of inclined holes are respectively used for transmitting the inclined optical signals in the 2M directions.

In some possible implementations, the fingerprint detection device further includes a transparent dielectric layer for connecting the at least one microlens, the at least one light blocking layer, and the plurality of optically sensitive pixels.

In some possible implementations, the fingerprint detection device further includes a filter layer disposed in an optical path between the at least one microlens and the plurality of optical sensing pixels or above the microlens for filtering out optical signals of non-target wavelength bands to transmit optical signals of target wavelength bands.

In a second aspect, there is provided an electronic device comprising:

a display screen; and

The apparatus for fingerprint detection as described in the first aspect or any one of the possible implementation manners of the first aspect, wherein the apparatus is disposed below the display screen to implement off-screen optical fingerprint detection.

Drawings

Fig. 1 is a schematic structural diagram of an electronic device to which the present application can be applied.

Fig. 2 is a schematic cross-sectional view of the electronic device shown in fig. 1.

Fig. 3 is another schematic structural diagram of an electronic device to which the present application can be applied.

Fig. 4 is a schematic cross-sectional view of the electronic device shown in fig. 3.

Fig. 5 to 29 are schematic structural diagrams of a fingerprint detection unit of an embodiment of the present application.

Fig. 30 is a schematic top view of a fingerprint detection device according to an embodiment of the present application.

Fig. 31 is a schematic side cross-sectional view of the fingerprint detection device shown in fig. 30 in the direction B-B'.

Fig. 32 is a schematic block diagram of optical path transmission in a scenario in which the light receiving direction of a finger is perpendicular to the fingerprint direction in an embodiment of the present application.

Fig. 33 is a schematic block diagram of optical path transmission in a scenario in which the light receiving direction of a finger is parallel to the fingerprint direction in an embodiment of the present application.

Fig. 34 to 37 are schematic structural diagrams of the relationship between the polarization direction of the display screen and the light receiving direction of the fingerprint detection device according to the embodiment of the present application.

Fig. 38 to 43 are schematic configuration diagrams of a fingerprint detection unit or a fingerprint detection device according to an embodiment of the present application.

Fig. 44 and 45 are a side sectional view of a fingerprint detection device for receiving a single direction and a schematic diagram of offset tolerance of a spot area in an optical sensing pixel according to an embodiment of the present application.

Fig. 46 and 47 are a side sectional view of a fingerprint detection device for receiving a bi-directional fingerprint and a schematic view of an offset tolerance of a spot area in an optical sensing pixel according to an embodiment of the present application, respectively.

Fig. 48 to 67 are another schematic configuration diagrams of a fingerprint detection unit or a fingerprint detection device according to an embodiment of the present application.

Fig. 68 is a schematic structural diagram of structural parameters in the fingerprint detection device according to an embodiment of the present application.

Fig. 69 and 70 are schematic plan views of the fingerprint detection device shown in fig. 68.

Detailed Description

The technical scheme of the application will be described below with reference to the accompanying drawings.

The technical scheme of the embodiment of the application can be applied to various electronic equipment. For example, smart phones, notebook computers, tablet computers, gaming devices, and other portable or mobile computing devices, as well as electronic databases, automobiles, automated teller machines (Automated TELLER MACHINE, ATM), and other electronic devices. However, the embodiment of the present application is not limited thereto.

The technical scheme of the embodiment of the application can be used for the biological characteristic recognition technology. The biometric technology includes, but is not limited to, fingerprint recognition, palm print recognition, iris recognition, face recognition, living body recognition, and the like. For ease of explanation, fingerprint recognition techniques are described below as examples.

The technical scheme of the embodiment of the application can be used for the under-screen fingerprint identification technology and the in-screen fingerprint identification technology.

The under-screen fingerprint identification technology is characterized in that the fingerprint identification module is arranged below the display screen, so that fingerprint identification operation is carried out in the display area of the display screen, and a fingerprint acquisition area is not required to be arranged in an area except the display area on the front side of the electronic equipment. Specifically, the fingerprint recognition module uses light returned from the top surface of the display assembly of the electronic device for fingerprint sensing and other sensing operations. This returned light carries information about an object (e.g., a finger) in contact with or in proximity to the top surface of the display assembly, and the fingerprint recognition module located below the display assembly performs off-screen fingerprint recognition by capturing and detecting this returned light. The fingerprint recognition module can be designed to realize expected optical imaging by properly configuring optical elements for collecting and detecting returned light, so as to detect fingerprint information of the finger.

Correspondingly, the In-screen (In-display) fingerprint identification technology refers to that a fingerprint identification module or a part of fingerprint identification modules are arranged inside a display screen, so that fingerprint identification operation is carried out In a display area of the display screen, and a fingerprint acquisition area is not required to be arranged In an area except the display area on the front side of the electronic equipment.

Fig. 1 to 4 show schematic diagrams of electronic devices to which embodiments of the present application may be applied. Fig. 1 and 3 are schematic diagrams illustrating the orientation of the electronic device 10, and fig. 2 and 4 are schematic diagrams illustrating the cross-section of the electronic device 10 illustrated in fig. 1 and 3, respectively. Referring to fig. 1 to 4, the electronic device 10 may include a display 120 and an optical fingerprint recognition module 130.

The display panel 120 may be a self-luminous display panel, which employs a display unit having self-luminescence as display pixels. For example, the display 120 may be an Organic Light-Emitting Diode (OLED) display or a Micro-LED (Micro-LED) display. In other alternative embodiments, the display 120 may be a Liquid crystal display (Liquid CRYSTAL DISPLAY, LCD) or other passive light emitting display, which is not limited in this respect. Further, the display screen 120 may be specifically a touch display screen, which not only can perform screen display, but also can detect touch or press operation of a user, so as to provide a personal computer interaction interface for the user. For example, in one embodiment, the electronic device 10 may include a Touch sensor, which may be specifically a Touch Panel (TP), which may be disposed on the surface of the display screen 120, or may be partially integrated or entirely integrated into the display screen 120, so as to form the Touch display screen.

The optical fingerprint module 130 includes an optical fingerprint sensor including a sensing array 133 having a plurality of optical sensing units 131 (which may also be referred to as optical sensing pixels, photosensitive pixels, pixel units, etc.). The sensing area of the sensing array 133 or the sensing area thereof is the fingerprint detection area 103 (also referred to as a fingerprint collection area, a fingerprint identification area, etc.) of the optical fingerprint module 130. For example, the optical sensing unit 131 may be a photodetector, i.e. the sensing array 133 may be a photodetector (Photo detector) array, which includes a plurality of photodetectors distributed in an array.

The optical fingerprint module 130 is disposed in a local area below the display screen 120.

With continued reference to fig. 1, the fingerprint detection area 103 may be located within a display area of the display 120. In an alternative embodiment, the optical fingerprint module 130 may be disposed at other locations, such as a side of the display screen 120 or an edge non-transparent area of the electronic device 10, and the optical signal from at least a portion of the display area of the display screen 120 is guided to the optical fingerprint module 130 through an optical path design, so that the fingerprint detection area 103 is actually located in the display area of the display screen 120.

For the electronic device 10, when the user needs to unlock the electronic device 10 or perform other fingerprint verification, the user only needs to press the finger on the fingerprint detection area 103 located on the display screen 120, so as to realize fingerprint input. Since fingerprint detection can be implemented in the screen, the electronic device 10 adopting the above structure does not need to 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.

With continued reference to fig. 2, the optical fingerprint module 130 may include a light detecting portion 134 and an optical component 132. The light detecting section 134 includes the sensing array 133 (may also be referred to as an optical fingerprint sensor) and a reading circuit and other auxiliary circuits electrically connected to the sensing array 133, which may be fabricated on a chip (Die) such as an optical imaging chip or an optical fingerprint sensor by a semiconductor process. 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, and other optical elements, where the Filter layer may be used to Filter out ambient light penetrating the finger, and the light guiding layer or the light path guiding structure is mainly used to guide reflected light reflected from the finger surface to the sensing array 133 for optical detection.

In some embodiments of the application, the optical assembly 132 may be packaged in the same optical fingerprint component as the light detection section 134. For example, the optical component 132 may be packaged in the same optical fingerprint chip as the optical detection portion 134, or the optical component 132 may be disposed outside the chip in which the optical detection portion 134 is located, for example, the optical component 132 is attached to the chip, or some of the components of the optical component 132 are integrated in the chip.

In some embodiments of the present application, the area or the light sensing range of the sensing array 133 of the optical fingerprint module 130 corresponds to the fingerprint detection area 103 of the optical fingerprint module 130. The fingerprint collection area 103 of the optical fingerprint module 130 may be equal to or different from the area or the light sensing range of the area where the sensing array 133 of the optical fingerprint module 130 is located, which is not particularly limited in the embodiment of the present application.

For example, the fingerprint detection area 103 of the optical fingerprint module 130 may be designed to be substantially identical to the area of the sensing array of the optical fingerprint module 130 by performing light path guidance through light collimation.

For another example, the area of the fingerprint detection area 103 of the optical fingerprint module 130 may be larger than the area of the sensing array 133 of the optical fingerprint module 130, for example, by a light path design such as lens imaging, a reflective folded light path design, or other light converging or reflecting light path design.

The following exemplifies the light path guiding structure that the optical assembly 132 may include.

Taking the optical path guiding structure as an example, an optical collimator with a through hole array with a high aspect ratio is adopted as the optical collimator, the optical collimator can be specifically a collimator (Collimator) layer manufactured on a semiconductor silicon wafer, the optical collimator is provided with a plurality of collimating units or micropores, the collimating units can be specifically small holes, light rays vertically incident to the collimating units can pass through and be received by sensor chips below the collimating units in reflected light reflected back from fingers, and light rays with overlarge incident angles are attenuated in the collimating units through repeated reflection, so that each sensor chip basically only can receive the reflected light reflected back by fingerprint lines right above the sensor chips, the image resolution can be effectively improved, and further the fingerprint identification effect is improved.

Taking the optical path design of the optical Lens as the optical path guiding structure, the optical path guiding structure may be an optical Lens (Lens) layer having one or more Lens units, such as a Lens group composed 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. Further, the optical lens layer may further be formed with a pinhole or a micropore diaphragm in the optical path of the lens unit, for example, one or more light shielding sheets may be formed in the optical path of the lens unit, wherein at least one light shielding sheet may be formed with a light-transmitting micropore in the optical axis or the optical center area of the lens unit, and the light-transmitting micropore may serve as the pinhole or micropore diaphragm. The pinhole or the microporous diaphragm may be matched with the optical lens layer and/or other optical film layers above the optical lens layer, so as to enlarge the field of view of the optical fingerprint module 130, so as to improve the fingerprint imaging effect of the optical fingerprint module 130.

Taking an optical path design in which the optical path guiding structure employs a Micro-Lens layer as an example, the optical path guiding structure may be a Micro-Lens array including a plurality of Micro-lenses, which may be formed over the sensing array 133 of the light sensing part 134 by a semiconductor growth process or other processes, and each Micro-Lens may correspond to one of sensing units of the sensing array 133, respectively. And other optical film layers, such as a dielectric layer or a passivation layer, can be formed between the microlens layer and the sensing unit. More specifically, a light blocking layer (or referred to as a light blocking layer, etc.) having micro holes (or referred to as openings) formed between its corresponding micro lens and sensing unit may be further included between the micro lens layer and the sensing unit, and the light blocking layer may block optical interference between adjacent micro lenses and sensing unit, and allow light corresponding to the sensing unit to be condensed into the micro holes by the micro lenses and transmitted to the sensing unit via the micro holes for optical fingerprint imaging.

It should be appreciated that several implementations of the above described optical path guiding structure 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 according to actual needs.

On the other hand, the optical component 132 may further include other optical elements, such as a Filter layer (Filter) or other optical film, which may be disposed between the optical path guiding structure and the optical fingerprint sensor or between the display screen 120 and the optical path guiding structure, and is mainly used to isolate the influence of the external interference light on the optical fingerprint detection. The filter layer may be used to filter out ambient light that penetrates through the finger and enters the optical fingerprint sensor through the display screen 120, similar to the light path guiding structure, and the filter layer may be separately disposed for each optical fingerprint sensor to filter out interference light, or may also use a large-area filter layer to cover the plurality of optical fingerprint sensors simultaneously.

The fingerprint recognition module 140 may be configured to collect fingerprint information (such as fingerprint image information) of a user.

Taking the display screen 120 as an example, a display screen having 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, is adopted. The optical fingerprint module 130 may use a display unit (i.e., an OLED light source) of the OLED display 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 target finger 140 above the fingerprint detection area 103, which light 111 is reflected at the surface of the finger 140 to form reflected light or scattered inside the finger 140 to form scattered light (transmitted light). In the related patent application, the above reflected light and scattered light are 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 and the reflected light 152 from the valley 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, thereby implementing an optical fingerprint recognition function at the electronic device 10.

In other alternatives, 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 and identification. In this case, the optical fingerprint module 130 may be applied to not only a self-luminous display screen such as an OLED display screen, but also a non-self-luminous display screen such as a liquid crystal display screen or other passive light-emitting 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, where the excitation light source may be specifically an infrared light source or a light source of non-visible light with a specific wavelength, which may be disposed below the backlight module of the liquid crystal display or an edge region below a protective cover plate of the electronic device 10, and the optical fingerprint module 130 may be disposed below the edge region of the liquid crystal panel or the protective cover plate and guided through an optical path so that fingerprint detection light may reach the optical fingerprint module 130; or the optical fingerprint module 130 may also be disposed below the backlight module, and the backlight module may be configured 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 or other optical designs on the film layers such as the diffusion sheet, the brightness enhancement sheet, and the reflection sheet. When the optical fingerprint module 130 is used to provide an optical signal for fingerprint detection using an internal light source or an external light source, the detection principle is consistent with the above description.

In a specific implementation, the electronic device 10 may further include a transparent protective cover plate, which may be a glass cover plate or a sapphire cover plate, located above the display screen 120 and covering the front surface of the electronic device 10. Thus, in the embodiment of the present application, the pressing of the finger against the display screen 120 actually means pressing the cover plate above the display screen 120 or the surface of the protective layer covering the cover plate.

On the other hand, the optical fingerprint module 130 may include only one optical fingerprint sensor, and at this time, 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, which may result in poor user experience. In other alternative embodiments, the optical fingerprint module 130 may specifically include a plurality of optical fingerprint sensors. The optical fingerprint sensors may be disposed side by side below the display screen 120 in a spliced manner, and the sensing areas of the optical fingerprint sensors together form the fingerprint detection area 103 of the optical fingerprint module 130. Thus, 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, that is, to the finger usual 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 be further extended to a half display area or even the whole display area, so as to implement half-screen or full-screen fingerprint detection.

Referring to fig. 3 and 4, the optical fingerprint module 130 in the electronic device 10 may include a plurality of optical fingerprint sensors, which may be disposed side by side under the display screen 120 by, for example, splicing, and the sensing areas of the plurality of optical fingerprint sensors together form the fingerprint detection area 103 of the optical fingerprint device 130.

Further, the optical component 132 may include a plurality of optical path guiding structures, where each optical path guiding structure corresponds to one optical fingerprint sensor (i.e. the sensing array 133) and is respectively disposed above the corresponding optical fingerprint sensor in a fitting manner. Alternatively, the plurality of optical fingerprint sensors may share a unitary light path guiding structure, i.e. the light path guiding structure has a sufficiently large area to cover the sensing array of the plurality of optical fingerprint sensors.

Taking the optical assembly 132 as an example, an optical collimator having a through hole array with a high aspect ratio is used, when the optical fingerprint module 130 includes a plurality of optical fingerprint sensors, one or more collimating units may be configured for one optical sensing unit in the optical sensing array of each optical fingerprint sensor, and the collimating units are attached to and disposed above the corresponding optical sensing units. Of course, the plurality of optical sensing units may also share one collimating unit, i.e. the one collimating unit has a sufficiently large aperture to cover the plurality of optical sensing units. Because one collimating unit can correspond to a plurality of optical sensing units or one optical sensing unit corresponds to a plurality of collimating units, the correspondence between the space period of the display screen 120 and the space period of the optical fingerprint sensor is destroyed, and therefore, even if the space structure of the luminous display array of the display screen 120 is similar to that of the optical sensing array of the optical fingerprint sensor, the optical fingerprint module 130 can be effectively prevented from generating moire fringes by utilizing the optical signals passing through the display screen 120 to perform fingerprint imaging, and the fingerprint recognition effect of the optical fingerprint module 130 is effectively improved.

Taking the optical component 132 as an example, when the optical fingerprint module 130 includes a plurality of sensor chips, one optical lens may be configured for each sensor chip to perform fingerprint imaging, or one optical lens may be configured for a plurality of sensor chips to perform light convergence and fingerprint imaging. Even when one sensor chip has two sensing arrays (Dual Array) or multiple sensing arrays (Multi-Array), two or more optical lenses may be configured for the sensor chip to perform optical imaging in cooperation with the two or more sensing arrays, so as to reduce the imaging distance and enhance the imaging effect.

It should be understood that fig. 1-4 are only examples of the present application and should not be construed as limiting the present application.

For example, the number, size and arrangement of the fingerprint sensors are not particularly limited, and can be adjusted according to actual requirements. For example, the optical fingerprint module 130 may include a plurality of fingerprint sensors distributed in a square or circular shape.

It should be noted that, when the optical guiding structure included in the optical component 132 is an optical collimator or a microlens array, the effective view of the sensing array 133 of the optical fingerprint module 130 is limited by the area of the optical component. Taking a microlens array as an example, in a general design, the microlens array is located directly above or obliquely above the sensor array 133, and one microlens corresponds to one optical sensor unit, that is, each microlens in the microlens array focuses the received light to the optical sensor unit corresponding to the same microlens. Thus, the fingerprint recognition area of the sensing array 133 is affected by the size of the microlens array.

Therefore, how to improve the fingerprint identification area is a technical problem to be solved.

The fingerprint detection device provided by the embodiment of the application is suitable for being used below a display screen to realize the optical fingerprint detection under the screen. The fingerprint detection device may be adapted to the electronic apparatus 10 shown in fig. 1-4, or the device may be the optical fingerprint module 130 shown in fig. 2 or 4. For example, the fingerprint detection device comprises a plurality of fingerprint detection units 21 as shown in fig. 5.

It should be understood that the fingerprint detection device may include a plurality of fingerprint detection units distributed in an array or staggered, and may also include a plurality of fingerprint detection units distributed in central symmetry or axisymmetric, which is not particularly limited in the embodiment of the present application. For example, the fingerprint detection device may comprise a plurality of fingerprint detection units arranged independently in a configuration but staggered in an arrangement. For example, two adjacent columns or rows of fingerprint detection units in the fingerprint detection device are staggered. Of course, the fingerprint detection device may also comprise a plurality of fingerprint detection units that are structurally staggered with respect to each other. For example, the microlenses in each of the fingerprint detection devices may converge the received oblique light signals to optically sensitive pixels below the microlenses in an adjacent plurality of fingerprint detection units. In other words, each microlens converges the received oblique light signal to an optically sensitive pixel under a plurality of microlenses adjacent to the same microlens.

Each fingerprint detection unit of the plurality of fingerprint detection units comprises a plurality of optical sensing pixels, at least one micro lens and at least one light blocking layer.

In a specific implementation, the at least one microlens may be disposed above the plurality of optical sensing pixels, or the plurality of optical sensing pixels may be disposed below a plurality of microlenses adjacent to the one microlens, respectively; the at least one light blocking layer can be arranged between the at least one micro lens and the plurality of optical sensing pixels, and an opening corresponding to the plurality of optical sensing pixels is arranged in each of the at least one light blocking layer. And after converging through the at least one micro lens, oblique optical signals in multiple directions reflected by the finger above the display screen are respectively transmitted to the multiple optical sensing pixels through the holes arranged in the at least one light blocking layer, and the oblique optical signals are used for detecting fingerprint information of the finger.

The oblique light signals received by the at least one microlens in the plurality of directions may be incident directions of oblique light for the at least one microlens. For example, the at least one microlens may be regarded as a whole, and in this case, in a top view, the directions may be optical signals received by the at least one microlens from up, down, left, and right directions, and angles between oblique optical signals in the 4 directions and a plane in which the display screen is located may be the same or different. The directions may be directions with respect to a plane in which the display screen is located, or directions with respect to a stereoscopic space. The directions may be different from each other or may be partially different.

The microlens may be various lenses having a converging function for increasing the field of view and increasing the amount of optical signals transmitted to the photosensitive pixels. The material of the microlenses may be an organic material, such as a resin.

The optically sensitive pixel may be a photosensor for converting an optical signal into an electrical signal. Alternatively, the optical sensing pixel may employ a complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS) device, a semiconductor device consisting of one PN junction, having unidirectional conductive properties. Optionally, the photosensitivity of the optical sensing pixel to blue light, green light, red light or infrared light is greater than a first predetermined threshold, and the quantum efficiency is greater than a second predetermined threshold. For example, the first predetermined threshold may be 0.5v/lux-sec and the second predetermined threshold may be 40%. That is, the photosensitive pixel has high light sensitivity and high quantum efficiency for blue light (wavelength of 460.+ -. 30 nm), green light (wavelength of 540.+ -. 30 nm), red light or infrared light (wavelength of. Gtoreq.610 nm) so as to detect the corresponding light.

It should be noted that, in the embodiment of the present application, specific shapes of the micro lens and the optical sensing pixel are not limited. For example, each of the plurality of photo-sensing pixels may be a polygonal pixel such as a quadrilateral or hexagonal pixel, or may be a pixel of another shape, such as a circular pixel, so that the plurality of photo-sensing pixels have higher symmetry, higher sampling efficiency, equidistant neighboring pixels, better angular resolution, and less aliasing effects. In addition, the above-mentioned parameter for the photo sensor pixel may correspond to light required for fingerprint detection, for example, if the light required for fingerprint detection is light of only one wavelength band, the above-mentioned parameter for the photo sensor pixel only needs to satisfy the requirement of the light of the wavelength band.

The signals received by the plurality of optical sensing pixels are oblique optical signals in a plurality of directions. I.e. optical signals in multiple directions of oblique incidence.

When the contact between the dry finger and the OLED screen is poor, the contrast between the fingerprint ridges and the fingerprint valleys of the fingerprint image in the vertical direction is poor, and the fingerprint lines cannot be distinguished from the image blurring. Under normal living scenes, such as hand washing, getting up in the morning, finger plastering, low temperature, etc., the fingers are usually dry, the horny layer is uneven, and poor contact can occur in local areas of the fingers when the fingers are pressed on an OLED screen. The present application has the beneficial effects of raising the imaging effect of dry finger print and making the dry finger print clear.

In addition, the oblique optical signals in the multiple directions can be imaged by the one micro lens in a non-opposite mode (namely, oblique optical imaging), so that the thickness of an optical path design layer between the one micro lens and the optical sensing pixel array can be shortened, and further, the thickness of the fingerprint detection device can be effectively reduced.

At the same time, by imaging oblique optical signals in multiple directions, the object numerical aperture of the optical system can be enlarged, and the robustness and tolerance of the fingerprint detection device can be further improved. Wherein the numerical aperture may be used to measure the angular range of light that the at least one microlens is capable of collecting. In other words, the plurality of optical sensing pixels can further expand the angle of view and the field of view of the fingerprint detection unit by receiving the optical signals in a plurality of directions, so as to further increase the angle of view and the field of view of the fingerprint detection device, for example, the field of view of the fingerprint detection device can be expanded from 6x9mm ² to 7.5x10.5mm ², and the fingerprint identification effect is further improved.

Moreover, by arranging a plurality of optical sensing pixels below the at least one microlens, when the number of the at least one microlens and the number of the plurality of optical sensing pixels are unequal, the spatial period of the microlens (i.e., the interval between adjacent microlenses) and the spatial period of the optical sensing pixels (i.e., the interval between adjacent optical sensing pixels) are unequal, so that moire fringes in a fingerprint image can be avoided and fingerprint identification effect can be improved. In particular, when the number of the at least one microlens is smaller than the number of the plurality of optical sensing pixels, the cost of the lens can be reduced, the density of the plurality of optical sensing pixels can be increased, and the size and the cost of the fingerprint detection device can be further reduced.

Meanwhile, the optical signals in multiple directions can be multiplexed through a single fingerprint detection unit (for example, 4-angle optical signals can be multiplexed through a single micro lens), light beams with different object space aperture angles can be split and imaged, the light inlet quantity of the fingerprint detection device is effectively improved, and therefore the exposure time of the optical sensing pixels can be reduced.

Moreover, since the plurality of optical sensing pixels can respectively receive oblique light signals from a plurality of directions, the plurality of optical sensing pixels can be divided into a plurality of optical sensing pixel groups according to the directions of the oblique light signals, the plurality of optical sensing pixel groups can respectively receive the oblique light signals from the plurality of directions, that is, each optical sensing pixel group can generate one fingerprint image based on the received oblique light signals, so that the plurality of optical sensing pixel groups can be used for generating a plurality of fingerprint images, in this case, the plurality of fingerprint images can be overlapped to obtain one fingerprint image with high resolution, and fingerprint recognition can be performed based on the fingerprint image with high resolution, so that fingerprint recognition performance can be improved.

Based on the above analysis, the oblique light signals in multiple directions reflected by the finger above the display screen are respectively transmitted to the multiple optical sensing pixels through the holes arranged in the at least one light blocking layer after being converged by the at least one micro lens, so that the exposure time of the multiple optical sensing pixels, the thickness and the cost of the fingerprint detection device can be reduced, the robustness, the tolerance, the angle of view and the field of view of the fingerprint detection device can be improved, and further the fingerprint recognition effect, especially the fingerprint recognition effect of dry fingers, is improved.

The fingerprint detection unit according to embodiments of the present application is described below with reference to the accompanying drawings.

In some embodiments of the application, the number of the at least one microlens is equal to the number of the plurality of photo-sensing pixels, wherein one microlens is disposed over each of the plurality of photo-sensing pixels.

In one implementation, the at least one microlens is a 2x2 rectangular array of microlenses, the plurality of optical sensing pixels is a 2x2 rectangular array of optical sensing pixels, and one microlens is disposed directly above each optical sensing pixel in the 2x2 rectangular array of optical sensing pixels. In another implementation, the at least one microlens is a 2x2 rectangular array of microlenses, the plurality of optical sensing pixels is a 2x2 rectangular array of optical sensing pixels, and one microlens is disposed obliquely above each optical sensing pixel in the 2x2 rectangular array of optical sensing pixels. For example, as shown in fig. 5, the fingerprint detection unit 21 may include 4 optical sensing pixels 211 and 4 microlenses 212 distributed in a rectangular array, wherein one microlens 212 is disposed directly above each optical sensing pixel 211. At this time, as shown in fig. 6, the fingerprint detection unit 21 may include a top light blocking layer and a bottom light blocking layer in terms of the light path design. Wherein the top light blocking layer may include 4 openings 2141 corresponding to the 4 microlenses 212, respectively, and the bottom light blocking layer may include 4 openings 213 corresponding to the 4 microlenses 212, respectively.

During light transmission, the 2x2 rectangular microlens array receives oblique light signals in the plurality of directions in a clockwise direction, each microlens in the 2x2 rectangular microlens array converges the received oblique light signals to an optically sensing pixel below an adjacent microlens in the clockwise direction, or the 2x2 rectangular microlens array receives oblique light signals in the plurality of directions in a counterclockwise direction, and each microlens in the 2x2 rectangular microlens array converges the received oblique light signals to an optically sensing pixel below an adjacent microlens in the counterclockwise direction. In connection with fig. 7, the 4 microlenses 212 can concentrate oblique light signals in multiple directions to the 4 photo-sensing pixels 211, respectively, along the following paths: the upper right microlens 212 converges the received oblique light signal to the upper left photo-sensing pixel 211, the upper left microlens 212 converges the received oblique light signal to the lower left photo-sensing pixel 211, the lower left microlens 212 converges the received oblique light signal to the lower right photo-sensing pixel 211, and the lower right microlens 212 converges the received oblique light signal to the upper right photo-sensing pixel 211. Therefore, when the fingerprint detection device comprises a plurality of fingerprint detection units distributed in an array, a plurality of fingerprint images can be generated based on the received light signals in a plurality of directions, and then a fingerprint image with high resolution is obtained, so that the fingerprint identification effect is improved.

In other words, the 4x4 fingerprint detection unit rectangular array may include an array of photo sensing pixels as shown in fig. 8, wherein "1" represents a photo sensing pixel for receiving a tilted light signal in a first direction, "2" represents a photo sensing pixel for receiving a tilted light signal in a second direction, "3" represents a photo sensing pixel for receiving a tilted light signal in a third direction, and "4" represents a photo sensing pixel for receiving a tilted light signal in a fourth direction. That is, the optical sensing pixels denoted by "1", "2", "3" and "4" may be used to generate one fingerprint image, that is, a total of 4 fingerprint images may be generated, and the 4 fingerprint images may be used to combine into one high-resolution fingerprint image, so as to further enhance the recognition effect of the fingerprint detection device. In connection with fig. 7, the first to fourth directions may be directions in which the lower right-hand microlens 212, the upper left-hand microlens 212, and the lower left-hand microlens 212 receive oblique light signals, respectively.

Fig. 9 is a side view of the fingerprint sensing device positioned below the display screen.

As shown in fig. 9, the fingerprint detection device may include microlenses 212 distributed in an array, a top-layer light blocking layer and a bottom-layer light blocking layer under the microlenses 212, and optical sensing pixels distributed in an array under the bottom-layer light blocking layer, wherein for each microlens 212, the top-layer light blocking layer and the bottom-layer light blocking layer are respectively formed with corresponding openings 2141 and openings 213. The fingerprint detection device is arranged below the display 216. Each microlens 212 converges the received oblique light signal with a specific direction (the light signal shown by the solid line in the figure) to the corresponding optical sensing pixel through the corresponding aperture 2141 and the aperture 213, and transmits the received oblique light signal with a non-specific direction (the light signal shown by the dashed line in the figure) to the area of the light blocking layer except the aperture 2141 and the aperture 214, so as to avoid being received by other optical sensing pixels, thereby causing the split imaging of the fingerprint image.

Fig. 10 is a schematic diagram of an optical path of an optical signal tilted for two directions according to an embodiment of the present application.

In connection with fig. 7, fig. 10 may be a schematic side sectional view of a fingerprint detection device in A-A' direction including the fingerprint detection unit shown in fig. 7, where one microlens 212 (e.g., the lower left microlens 212 shown in fig. 7) in the fingerprint detection unit converges a received oblique light signal (light signal shown in solid line in fig. 10) in one direction (i.e., the fourth direction) to a corresponding photo-sensing pixel (e.g., the lower right photo-sensing pixel 211 shown in fig. 7) through a corresponding aperture 2141 and aperture 213, and another microlens 212 (e.g., the upper right microlens 212 shown in fig. 7) in the fingerprint detection unit converges a received oblique light signal (light signal shown in broken line in fig. 10) in another direction (i.e., the second direction) to a corresponding photo-sensing pixel (e.g., the upper left photo-sensing pixel 211 shown in fig. 7) through a corresponding aperture 2141 and aperture 213.

In the fingerprint acquisition process, the fingerprint identification area (also referred to as a fingerprint acquisition area or a fingerprint detection area) of the fingerprint detection device shown in fig. 10 includes a first identification area and a second identification area, wherein the fingerprint identification area corresponding to the micro lens 212 for converging the oblique light signal in the second direction is the first identification area, and the fingerprint identification area corresponding to the micro lens for converging the oblique light signal in the fourth direction is the second identification area. The first identification area is offset to the right by a first incremental area relative to the array of photo-sensing pixels and the second identification area is offset to the left by a second incremental area relative to the column of photo-sensing pixels. In other words, assuming that the first identification area and the second identification area are equal to the area where the optical sensing array is located, the identification area of the fingerprint detection device shown in fig. 10 additionally includes the first added area and the second added area, and effectively increases the visible area (i.e., the field of view) relative to the fingerprint detection device that only receives the optical signal in one direction. In addition, the overlapping area of the first identification area and the second identification area can effectively improve the image resolution of the fingerprint image, and further improve the fingerprint identification effect.

It should be understood that the optical path design shown in fig. 7 is only an example of the present application and should not be construed as limiting the application.

For the optical path design, in another implementation, the 2x2 rectangular microlens array receives oblique optical signals in the multiple directions along a diagonal direction of the 2x2 rectangular microlens array, and each microlens in the 2x2 rectangular microlens array converges the received oblique optical signals to an optically-sensitive pixel below an adjacent microlens in the diagonal direction. For example, as shown in fig. 11 and 12, the 4 microlenses 212 can converge oblique light signals in multiple directions to the 4 photo-sensing pixels 211, respectively, along the following paths: the upper right microlens 212 converges the received oblique light signal to the lower left photo-sensing pixel 211, the lower left microlens 212 converges the received oblique light signal to the upper right photo-sensing pixel 211, the upper left microlens 212 converges the received oblique light signal to the lower right photo-sensing pixel 211, and the lower right microlens 212 converges the received oblique light signal to the upper left photo-sensing pixel 211. Therefore, when the fingerprint detection device comprises a plurality of fingerprint detection units distributed in an array, a plurality of fingerprint images can be generated based on the received light signals in a plurality of directions, and then a fingerprint image with high resolution is obtained, so that the fingerprint identification effect is improved.

Similarly, the 4x4 fingerprint detection unit rectangular array may comprise an array of photo sensing pixels as shown in fig. 8, wherein "1" represents a photo sensing pixel for receiving a tilted light signal in a first direction, "2" represents a photo sensing pixel for receiving a tilted light signal in a second direction, "3" represents a photo sensing pixel for receiving a tilted light signal in a third direction, and "4" represents a photo sensing pixel for receiving a tilted light signal in a fourth direction. That is, the optical sensing pixels denoted by "1", "2", "3" and "4" may be used to generate one fingerprint image, that is, a total of 4 fingerprint images may be generated, and the 4 fingerprint images may be used to combine into one high-resolution fingerprint image, so as to further enhance the recognition effect of the fingerprint detection device. In connection with fig. 11, the first to fourth aspects may be directions in which the lower left microlens 212, the lower right microlens 212, the upper right microlens 212, and the upper left microlens 212 receive oblique light signals, respectively.

The fingerprint detection device may comprise at least one light blocking layer and an array of optically sensitive pixels. In one implementation, the at least one light blocking layer is a plurality of light blocking layers. One opening in the array of apertures in each of the plurality of light blocking layers corresponds to a plurality of optically sensing pixels in the optically sensing pixels, or one opening in the array of apertures in each of the plurality of light blocking layers corresponds to one optically sensing pixel in the optically sensing pixels. For example, one opening in the array of apertures in a top light blocking layer of the plurality of light blocking layers corresponds to a plurality of light sensing pixels of the light sensing pixels. For another example, one opening in the array of apertures in a top light blocking layer of the plurality of light blocking layers corresponds to one of the light sensing pixels. One opening in the array of apertures in the bottom one of the plurality of light blocking layers corresponds to one of the photo-sensing pixels. Optionally, the openings corresponding to the same optical sensing pixel in the plurality of light blocking layers sequentially decrease from top to bottom. In another implementation, the at least one light blocking layer is one light blocking layer. Optionally, the thickness of the one light blocking layer is greater than a preset threshold. Optionally, a metal wiring layer of the optical sensing pixel array is disposed at a back focal plane position of the microlens array, and the metal wiring layer has an opening above each optical sensing pixel in the optical sensing pixel array to form the bottom light blocking layer.

In other words, the fingerprint detection unit may include at least one light blocking layer and a plurality of optical sensing pixels, wherein an opening corresponding to the plurality of optical sensing pixels is disposed in each of the at least one light blocking layer. For example, the at least one light blocking layer may be a multilayer light blocking layer, and a top light blocking layer of the multilayer light blocking layer may be provided with at least one opening corresponding to the plurality of optically sensitive pixels. For example, one aperture of the array of apertures in the top light blocking layer corresponds to at least two of the plurality of photo-sensing pixels. For example, as shown in fig. 12, the at least one light blocking layer may include a top light blocking layer and a bottom light blocking layer, wherein the top light blocking layer is provided with 4 openings 2141 corresponding to 4 photo-sensing pixels, respectively. The bottom light blocking layer is provided with 4 openings 213 corresponding to the 4 optical sensing pixels respectively. As another example, as shown in fig. 13, the at least one light blocking layer may include a top light blocking layer and a bottom light blocking layer, wherein the top light blocking layer is provided with 1 aperture 2142 corresponding to 4 photo-sensing pixels. The bottom light blocking layer is provided with 4 openings 213 corresponding to the 4 optical sensing pixels respectively.

Note that, the aperture provided in the light blocking layer in fig. 12 and 13 is described by way of example only with respect to the fingerprint detection unit shown in fig. 11, and the implementation is applicable to various embodiments of the present application, which is not limited thereto. For example, the at least one light blocking layer may be a light blocking layer of more than 2 layers. Or the at least one light-blocking layer may be a light-blocking layer, i.e. the at least one light-blocking layer may be a straight-hole collimator or a number of hole collimators having a certain thickness. It should also be understood that fig. 5-13 are only examples of one microlens disposed over each photo-sensing pixel, and should not be construed as limiting the application. For example, the fingerprint detection unit may also comprise other numbers or other arrangements of micro-lenses or optically sensitive pixels. For example, in another implementation, the at least one microlens is a plurality of rows of microlenses, and the plurality of optical sensing pixels are a plurality of rows of optical sensing pixels corresponding to the plurality of rows of microlenses, where each row of optical sensing pixels in the plurality of rows of optical sensing pixels is disposed below a corresponding row of microlenses in a staggered manner. Alternatively, the plurality of rows of microlenses may be a plurality of columns or rows of microlenses. The plurality of rows of photo-sensing pixels may be a plurality of columns or a plurality of rows of photo-sensing pixels.

The at least one light blocking layer may be provided with a corresponding light path design, so that the multiple rows of microlenses receive oblique light signals in multiple directions along the dislocation direction of the multiple rows of optical sensing pixels, and each row of microlenses of the multiple rows of microlenses converges the received oblique light signals to the optical sensing pixels under the same row of microlenses or an adjacent row of microlenses.

For example, as shown in fig. 14, the fingerprint detection unit 22 may include 4 columns of optical sensing pixels distributed in a rectangular array and 4 columns of microlenses corresponding to the 4 columns of optical sensing pixels, where each column of optical sensing pixels in the 4 columns of optical sensing pixels includes 6 optical sensing pixels 221, each column of microlenses in the 4 columns of microlenses includes 6 microlenses 222, and one optical sensing pixel 221 is disposed below one microlens 222 in a staggered manner. The fingerprint detection unit 22 may further comprise a top light blocking layer and a bottom light blocking layer. At this time, for each microlens 222, the top light blocking layer and the bottom light blocking layer may be provided with their corresponding openings 2241 and 2231, respectively. Each microlens 222 of each of the plurality of rows of microlenses may converge the received optical signal to the optical sensing pixel 221 obliquely below the same microlens 222 through the corresponding aperture 2241 and aperture 2231. Therefore, when the fingerprint detection device comprises a plurality of fingerprint detection units distributed in an array, a plurality of fingerprint images can be generated based on the received light signals in a plurality of directions, and then a fingerprint image with high resolution is obtained, so that the fingerprint identification effect is improved.

In other words, the fingerprint detection unit shown in fig. 14 may include an array of photo sensing pixels as shown in fig. 15, wherein "1" represents a photo sensing pixel for receiving a tilted light signal in a first direction and "2" represents a photo sensing pixel for receiving a tilted light signal in a second direction. That is, "1" and "2" indicate that the optical sensing pixels can be used to generate one fingerprint image, that is, 2 fingerprint images can be generated in total, and the 2 fingerprint images can be used to combine into one high-resolution fingerprint image, so as to further improve the recognition effect of the fingerprint detection device. In connection with fig. 14, the first direction may be a direction in which oblique light signals are received for the microlenses in the first and second columns, and the second direction may be a direction in which oblique light signals are received for the microlenses in the third and fourth columns, based on the order from left to right.

In one embodiment of the present application, a projection of each microlens of each of the plurality of rows of microlenses on a plane of the display screen is a circle, a projection of each optical sensing pixel of each of the plurality of rows of optical sensing pixels on the plane of the display screen is a rectangle, a projection of a center of each optical sensing pixel of each of the plurality of rows of optical sensing pixels on the plane of the display screen is offset by a preset distance along a dislocation direction of the plurality of rows of optical sensing pixels, the preset distance is smaller than or equal to a side length of the rectangle, or the preset distance is smaller than or equal to a diameter of the circle. Alternatively, each of the plurality of rows of microlenses is offset in the misalignment direction by a predetermined distance along the respective misalignment direction. For example, in one implementation, as shown in fig. 14, the misalignment direction is a diagonal direction of each of the plurality of rows of photo-sensing pixels, that is, each of the plurality of rows of micro-lenses 222 is offset by a preset distance along the diagonal direction of the same photo-sensing pixel 221. At this time, the corresponding openings 2241 and 2231 may be disposed above each of the photo-sensing pixels 221 in each of the plurality of rows of photo-sensing pixels, that is, the at least one light blocking layer in the fingerprint detection unit 22 is disposed above each of the photo-sensing pixels 221. Of course, the offset direction may also be the direction in which the vertical side length of each of the plurality of rows of the photo-sensing pixels is located. For example, the misalignment direction may be a direction in which a row or a column of the optical sensing pixel array is located.

Note that, the preset distance may also be an offset distance in a direction in which the side length of the optical sensing pixel 221 is located, for example, an X-axis direction and a Y-axis direction are taken as two side lengths of the optical sensing pixel 221, where the preset distance may include an offset distance along the X-axis direction and an offset distance along the Y-axis direction. For example, assuming that the side length of the photo-sensing pixel is 12.5mm, the diameter of the micro-lens is 11.5mm, the offset distance along the X-axis direction may be 4 to 5mm, and the offset distance along the Y-axis direction may be 4 to 5mm. Of course, the above parameters are only examples and should not be construed as limiting itself, for example, the offset distance along the X-axis direction may not be equal to the offset distance along the Y-axis direction, and for example, the offset distance along the X-axis direction or the offset distance along the Y-axis direction may be greater than 5mm or less than 4mm.

In another implementation, as shown in fig. 16, the fingerprint detection unit 22 may include a top light blocking layer and a bottom light blocking layer for the misalignment direction. At this time, for each microlens 222, the top light blocking layer and the bottom light blocking layer may be provided with their corresponding openings 2242 and 2232, respectively. Wherein each microlens 222 of each of the plurality of rows of microlenses can converge the received oblique optical signal to the photo-sensing pixel 221 directly below the adjacent microlens 222 through the corresponding aperture 2242 and aperture 2232. For example, the upper left hand corner microlens 222 may converge the received oblique light signal to the photo-sensing pixel 221 directly below the adjacent second row first column microlens 222. At this time, the bottom light blocking layer may be provided with its corresponding opening 2232 over each of the photo-sensing pixels 221 of each of the plurality of rows of photo-sensing pixels, and the top light blocking layer may be provided with its corresponding opening 2242 over the photo-sensing pixels 221 adjacent to the same photo-sensing pixel 221.

It should be understood that the misalignment direction may be other directions. For example, the misalignment direction is a direction in which a horizontal side length of each of the plurality of rows of the photo-sensing pixels is located. For another example, the offset direction may be a direction in which the rows or columns of the plurality of rows of the optical sensing pixels are located.

In other embodiments of the present application, the number of the at least one microlens is less than the number of the plurality of photo-sensing pixels.

In one implementation, the at least one microlens is one microlens, and the plurality of photo-sensing pixels is a rectangular array of 2x2 photo-sensing pixels, wherein the one microlens is disposed directly above the rectangular array of 2x2 photo-sensing pixels. For example, as shown in fig. 17, the fingerprint detection unit 23 may include one microlens 232 and 4 optical sensing pixels 231 distributed in a rectangular array.

In a specific optical path design, at least one light blocking layer in the fingerprint detection unit 23 may be provided with openings corresponding to the 4 optical sensing pixels 231 below one microlens, so that the one microlens may receive the oblique optical signals in the multiple directions along the diagonal direction of the 2x2 optical sensing pixel rectangular array, and the one microlens may converge the oblique optical signals in the multiple directions to the optical sensing pixels in the optical sensing pixel rectangular array along the diagonal direction, so as to increase the signal amount that each optical sensing pixel may receive, and further improve the fingerprint recognition effect. For example, as shown in fig. 18 or 19, the at least one light blocking layer may include a top light blocking layer and a bottom light blocking layer. The top light blocking layer is provided with openings 2341 corresponding to the 4 optical sensing pixels 231 below the one microlens 232, and the bottom light blocking layer is provided with openings 232 corresponding to the 4 optical sensing pixels 231 below the one microlens 232. The one microlens 232 converges the received light signals in multiple directions to the 4 photo-sensing pixels 231 through the corresponding aperture 2341 and the aperture 232, respectively. Of course, the 4 small holes of the top light blocking layer corresponding to the 4 optical sensing pixels 231 may be combined into one large hole. Such as the aperture 2342 shown in fig. 20 or 21.

In another implementation, the one microlens is a 2x2 microlens rectangular array, the plurality of optical sensing pixels is a 3x3 optical sensing pixel rectangular array, and one microlens is disposed right above each adjacent 4 optical sensing pixels in the 3x3 rectangular array. For example, a microlens is disposed right above the center position of each adjacent 4 optical sensing pixels in the 3x3 rectangular array. For example, as shown in fig. 22, the fingerprint detection unit 24 may include 4 microlenses 242 distributed in a rectangular array and 9 optical sensing pixels 241 distributed in a rectangular array.

In a specific optical path design, as shown in fig. 23, at least one light blocking layer in the fingerprint detection unit 24 may be respectively provided with openings corresponding to the optical sensing pixels 241 on the 4 corners of the rectangular array of 3x3 optical sensing pixels, so that each microlens 242 in the rectangular array of 2x2 microlenses may converge the received oblique optical signal to the optical sensing pixel 241 closest to the same microlens 424 among the optical sensing pixels 241 on the 4 corners of the rectangular array of 3x3 optical sensing pixels. For example, the at least one light blocking layer may include a top light blocking layer and a bottom light blocking layer. The top light blocking layer is provided with openings 244 corresponding to the optical sensing pixels 241 at the 4 corners, and the bottom light blocking layer is provided with openings 243 corresponding to the optical sensing pixels 241 at the 4 corners. Thus, the 4 microlenses 242 can converge the oblique light signals in the multiple directions through the corresponding apertures 2341 and 243 to the photo-sensing pixels 241 at the 4 corners, respectively.

Since only 4 photo-sensing pixels 241 in the rectangular array of 3x3 photo-sensing pixels receive oblique light signals for detecting fingerprint information, in order to increase the utilization of the photo-sensing pixels, in some embodiments of the present application, a fingerprint detection device including a plurality of fingerprint detection units 24 may be formed by staggering. For example, as shown in fig. 24, a central fingerprint detection unit located at an intermediate position, in which the optical sensing pixel 241 between the upper left and right optical sensing pixels 241 and 241 may be multiplexed as the optical sensing pixel 241 located at the lower left of the other fingerprint detection unit, in which the optical sensing pixel 241 between the upper left and lower left optical sensing pixels 241 and 241 may be multiplexed as the optical sensing pixel 241 located at the lower right of the other fingerprint detection unit, in which the optical sensing pixel 241 between the lower left and lower right optical sensing pixels 241 and 241 may be multiplexed as the optical sensing pixel 241 located at the upper right of the other fingerprint detection unit, and in which the optical sensing pixel 241 between the lower right and upper right optical sensing pixels 241 may be multiplexed as the optical sensing pixel 241 located at the upper left of the other fingerprint detection unit.

In other words, the fingerprint detection device may comprise a plurality of photo sensing pixels as shown in fig. 25, wherein "0" represents photo sensing pixels not used for receiving optical signals, "1", "2", "3" and "4" represent photo sensing pixels used for receiving 4 different directions, respectively, and the blank space represents photo sensing pixels that can be multiplexed into other fingerprint detection units. That is, the optical sensing pixels denoted by "1", "2", "3" and "4" may be used to generate one fingerprint image, that is, a total of 4 fingerprint images may be generated, and the 4 fingerprint images may be used to combine into one high-resolution fingerprint image, so as to further enhance the recognition effect of the fingerprint detection device.

In another implementation, the at least one microlens is a 3x3 rectangular array of microlenses, the plurality of optical sensing pixels is a 4x4 rectangular array of optical sensing pixels, and one microlens is disposed right above each adjacent 4 optical sensing pixels in the 4x4 rectangular array of optical sensing pixels. For example, as shown in fig. 26, the fingerprint detection unit 25 may include 9 microlenses 252 distributed in a rectangular array and 16 optical sensing pixels 251 distributed in a rectangular array. Wherein, one microlens 252 is disposed right above each adjacent 4 optical sensing pixels 251 of the 16 optical sensing pixels 251.

In a specific optical path design, at least one layer of light blocking layer in the fingerprint detection unit 25 may be respectively provided with openings corresponding to the 16 optical sensing pixels 251, so that the central microlens in the 3x3 microlens rectangular array converges the received oblique light signals to the 4 optical sensing pixels below the central microlens, each of the microlenses at the 4 corners in the 3x3 microlens rectangular array converges the received oblique light signals to the optical sensing pixels below the same microlens at the corners of the 4x4 optical sensing pixel rectangular array, and each of the other microlenses in the 3x3 microlens rectangular array converges the received oblique light signals to the two optical sensing pixels outside below the same microlens. For example, as shown in fig. 27, the at least one light blocking layer may include a top light blocking layer and a bottom light blocking layer. The top light blocking layer is provided with openings 2541 corresponding to the 16 optical sensing pixels 251 respectively, and the bottom light blocking layer is provided with openings 253 corresponding to the 16 optical sensing pixels 251 respectively. Thus, the 9 microlenses 252 can converge the oblique light signals in the multiple directions to the 16 photo-sensing pixels 251 through the corresponding apertures 2341 and 243, respectively.

In other words, the fingerprint detection device may comprise a plurality of photo sensing pixels as shown in fig. 28, wherein "1", "2", "3" and "4" respectively denote photo sensing pixels for receiving 4 different directions. That is, the optical sensing pixels denoted by "1", "2", "3" and "4" may be used to generate one fingerprint image, that is, a total of 4 fingerprint images may be generated, and the 4 fingerprint images may be used to combine into one high-resolution fingerprint image, so as to further enhance the recognition effect of the fingerprint detection device.

Of course, FIG. 27 is merely an example of the present application and should not be construed as limiting the application.

For example, as shown in fig. 29, two small holes corresponding to the light blocking layer at the top layer of two optical sensing pixels 251 located between two corners in the rectangular array of 4x4 optical sensing pixels may be combined into one large hole, and four small holes corresponding to the light blocking layer at the top layer of 4 adjacent optical sensing pixels 251 located at the center position in the rectangular array of 4x4 optical sensing pixels may be combined into one large hole, so as to reduce processing difficulty, increase converged light signal quantity, and further improve fingerprint identification effect of the fingerprint detection device.

The fingerprint detection units which can be arranged in a staggered manner are described above, and the fingerprint detection units which are arranged in a staggered manner in the light path structure are described below.

For example, the fingerprint detection device may include a plurality of fingerprint detection units distributed in an array or staggered, each of the plurality of fingerprint detection units may include one microlens, at least one light blocking layer, and a plurality of optical sensing pixels, each of the at least one light blocking layer is provided with an opening corresponding to the plurality of optical sensing pixels, and the at least one light blocking layer is disposed between the one microlens and the plurality of optical sensing pixels. The micro lenses in the fingerprint detection units can converge the received oblique light signals to the optical sensing pixels in the adjacent fingerprint detection units. In other words, the plurality of optically sensitive pixels in each of the fingerprint detection devices are configured to receive oblique light signals converging from the microlenses in adjacent ones of the plurality of fingerprint detection units. For convenience of description, a plurality of fingerprint detection units arranged alternately will be described from the viewpoint of the fingerprint detection device.

Fig. 30 is a schematic top view of the fingerprint detection device 30 according to an embodiment of the present application, and fig. 31 is a side cross-sectional view of the fingerprint detection device 30 shown in fig. 30 along the direction B-B'.

As shown in fig. 30, the fingerprint detection device 30 may comprise 3x3 fingerprint detection units, wherein each of the 3x3 fingerprint detection units comprises one microlens and a rectangular array of 2x2 optically sensitive pixels located below the one microlens. Taking an intermediate fingerprint detection unit located in an intermediate position in the 3x3 fingerprint detection unit as an example, the 2x2 optical sensing pixel rectangular arrays in the intermediate fingerprint detection unit are respectively used for receiving oblique light signals converged by microlenses in fingerprint detection units located at 4 corners in the 3x3 fingerprint detection unit. In other words, the microlenses in the central fingerprint detection unit located at the central position in the 3x3 fingerprint detection unit rectangular array are used to converge the received oblique light signals in multiple directions along the diagonal direction of the 3x3 fingerprint detection unit rectangular array to the optical sensing pixels in the adjacent fingerprint detection units close to the central fingerprint detection unit.

As shown in fig. 31, the fingerprint detection device 30 may comprise a microlens array 310, at least one light blocking layer, and an optically sensitive pixel array 340. The microlens array 310 may be configured to be disposed under a display screen of an electronic device, the at least one light blocking layer may be disposed under the microlens array 310, and the optical sensing pixel array 340 may be disposed under the at least one light blocking layer. The microlens array 310 and the at least one light blocking layer may be light guiding structures included in the optical assembly 132 shown in fig. 3 or fig. 4, and the optical sensing pixel array 340 may be the sensing array 133 having the plurality of optical sensing units 131 (may also be referred to as optical sensing pixels, photosensitive pixels, pixel units, etc.) shown in fig. 1 to fig. 4, and the repetition is avoided.

The microlens array 310 includes a plurality of microlenses. For example, the microlens array 310 may include a first microlens 311, a second microlens 312, and a third microlens 313. The at least one light blocking layer may include a plurality of light blocking layers, for example, the at least one light blocking layer may include a first light blocking layer 320 and a second light blocking layer 330. The photo-sensing pixel array 340 may include a plurality of photo-sensing pixels, for example, the photo-sensing pixel array may include a first photo-sensing pixel 341, a second photo-sensing pixel 342, a third photo-sensing pixel 343, a fourth photo-sensing pixel 344, a fifth photo-sensing pixel 345, and a sixth photo-sensing pixel 346. At least one opening corresponding to each of the plurality of microlenses (i.e., the first microlens 311, the second microlens 312, and the third microlens 313) is provided in the first light blocking layer 320 and the second light blocking layer 330, respectively. For example, the first light blocking layer 320 is provided with first and second openings 321 and 322 corresponding to the first microlenses 311, the first light blocking layer 320 is further provided with second and third openings 322 and 323 corresponding to the second microlenses 312, and the first light blocking layer 320 is provided with third and fourth openings 323 and 324 corresponding to the third microlenses 313. Similarly, the second light blocking layer 330 is provided with fifth and sixth openings 331 and 332 corresponding to the first microlenses 311, the second light blocking layer 330 is further provided with seventh and eighth openings 333 and 334 corresponding to the second microlenses 312, and ninth and tenth openings 335 and 336 corresponding to the third microlenses 313 are provided in the second light blocking layer 330.

In a specific optical path design, a plurality of optical sensing pixels are disposed under each microlens in the microlens array 310. The optical sensing pixels arranged below each micro lens are respectively used for receiving optical signals converged by the adjacent micro lenses. Taking the second microlens 312 as an example, a third optical sensing pixel 343 and a fourth optical sensing pixel 344 may be disposed below the second microlens 312, wherein the third optical sensing pixel 343 may be configured to receive the oblique optical signal converged by the first microlens 311 and passing through the second aperture 322 and the seventh aperture 333, and the fourth optical sensing pixel 344 may be configured to receive the oblique optical signal converged by the third microlens 313 and passing through the third aperture 323 and the eighth aperture 334.

In other words, the at least one light blocking layer is formed with a plurality of light guide channels corresponding to each microlens in the microlens array 310, and bottoms of the plurality of light guide channels corresponding to each microlens extend below the adjacent plurality of microlenses, respectively. Taking the second microlens 312 as an example, the plurality of light guiding channels corresponding to the second microlens 312 may include a light guiding channel formed by the second opening 322 and the sixth opening 332, and a light guiding channel formed by the third opening 323 and the ninth opening 335. The light guide channel formed by the second aperture 322 and the sixth aperture 332 extends below the first microlens 311, and the light guide channel formed by the third aperture 323 and the ninth aperture 335 extends below the third microlens 313. An optical sensing pixel may be disposed under each of the plurality of light guide channels corresponding to each microlens in the microlens array 310. Taking the second microlens 312 as an example, the second optical sensing pixel 342 is disposed below the light guiding channel formed by the second opening 322 and the sixth opening 332, and the fifth optical sensing pixel 345 is disposed below the light guiding channel formed by the third opening 323 and the ninth opening 335.

Through the reasonable design of a plurality of light guide channels corresponding to each microlens, the optical sensing pixel array 340 can receive oblique light signals in a plurality of directions, and the oblique light signals in a plurality of directions are converged through a single microlens, so that the problem of overlong exposure time of a single object space telecentric microlens array scheme can be solved. In other words, the fingerprint detection device 30 can solve the problems of poor recognition effect of the vertical light signal on the dry finger and too long exposure time of the single-object-space telecentric microlens array scheme, and can also solve the problems of too large thickness, too poor tolerance and too large size.

It should be understood that the arrangement and the size of the optical sensing pixel array are not particularly limited in the embodiments of the present application. For example, the fingerprint detection unit may comprise a plurality of optically sensitive pixels distributed in a polygon (e.g. diamond), circle or oval shape.

With continued reference to fig. 31, the fingerprint detection device 30 may further comprise a transparent dielectric layer 350.

Wherein the transparent dielectric layer 350 may be disposed at least one of the following locations: between the microlens array 310 and the at least one light blocking layer; the at least one light blocking layer is arranged between the light blocking layers; and between the at least one light blocking layer and the photo-sensing pixel array 340. For example, the transparent dielectric layer 350 may include a first dielectric layer 351 positioned between the microlens array 310 and the at least one light blocking layer (i.e., the first light blocking layer 320) and a second dielectric layer 352 positioned between the first light blocking layer 320 and the second light blocking layer 330.

The material of the transparent dielectric layer 350 is any transparent material transparent to light, such as glass, or may be air or vacuum transition, which is not particularly limited in the present application.

The fingerprint detection device for receiving 4-directional oblique optical signals was described above, but embodiments of the present application are not limited thereto. The fingerprint detection device may also be used to receive oblique light signals in two or three directions to achieve the benefits referred to above.

In some embodiments of the present application, the fingerprint detection device is adapted to be used under a display screen to realize optical fingerprint detection under the screen, and the fingerprint detection device includes a plurality of fingerprint detection units distributed in an array or staggered, each fingerprint detection unit in the plurality of fingerprint detection units includes at least one microlens, at least one light blocking layer under the at least one microlens, and a plurality of optical sensing pixels under the at least one light blocking layer.

Wherein the at least one microlens is disposed above the plurality of optical sensing pixels; the at least one light blocking layer is arranged between the at least one micro lens and the plurality of optical sensing pixels, and each light blocking layer of the at least one light blocking layer is provided with an opening corresponding to the plurality of optical sensing pixels; and after the inclined optical signals in 2M directions reflected by the finger above the display screen are converged by the at least one micro lens, the inclined optical signals are respectively transmitted to the plurality of optical sensing pixels through the holes arranged in the at least one light blocking layer, the inclined optical signals are used for detecting fingerprint information of the finger, and M is a positive integer.

In some embodiments of the application, the 2M directions include a first direction and a second direction, a projection of the first direction on the display screen being perpendicular to a projection of the second direction on the display screen.

In general, a fingerprint comprises raised ridges and recessed valleys, and an optical fingerprint system is imaged by means of reflected light from the fingerprint surface, as shown in fig. 32, when the incident light is perpendicular to the fingerprint direction, the reflected light from the valleys is blocked by the sides of the ridges so that the differences between the ridges and the valleys are more obvious; as shown in fig. 33, when the incident light is parallel to the fingerprint direction, the reflected light of the valleys is not blocked by the sides of the ridges, and the differences between the ridges and the valleys are not obvious. If the light receiving direction is a single direction, since the direction of pressing the fingerprint is random, the pressed fingerprint is likely to be parallel to the light receiving direction, and the fingerprint signal is poor at this time, which may be difficult to identify. In the multi-directional light receiving scheme, signal light with different angles is collected, for example, orthogonal two-way light receiving is taken as an example, if one direction receives the worst signal (parallel to the fingerprint direction), the other direction receives the best signal (perpendicular to the fingerprint direction). The multidirectional (bidirectional) light receiving scheme can receive good signals under the condition that the fingerprints are pressed randomly, and the identification capability of the fingerprints is improved.

In some embodiments of the application, the projection of the first direction or the second direction on the display screen is perpendicular to the polarization direction of the display screen.

Typically, the display screen of an electronic device is an OLED screen having polarization characteristics with a polarization direction at 45 degrees or 135 degrees from the horizontal (or vertical) direction of the screen. For example, polarization direction 361 as shown in fig. 34 or polarization direction 366 as shown in fig. 35. The polarization characteristics of the OLED screen make the signal quantity of the fingerprint different according to the angle between the incident plane and the polarization direction. The signal is greatest when the plane of incidence is perpendicular to the polarization direction and the signal is least when the plane of incidence is parallel to the polarization direction. In other words, the best light receiving direction for a screen with a 45 degree polarization direction is exactly the worst light receiving direction for a screen with a 135 degree polarization direction.

Therefore, in order to ensure that both screens can be used, the single light receiving direction scheme can only select a direction 45 degrees or 135 degrees from the optimal light receiving direction as the light receiving direction. For example, as shown in fig. 34 or 35, the light receiving direction of the fingerprint detection device 362 is the direction 363 or the direction opposite to the direction 363.

For the multi-directional light receiving scheme, taking an orthogonal four-way or two-way light receiving scheme as an example, signal light rays in four (two) directions can be received simultaneously, so that signal light in the optimal direction can be received under the screen of 45 degrees and 135 degrees. For example, as shown in fig. 36, the light receiving directions of the fingerprint detection device 362 are a direction 364 and a direction 365. As another example, as shown in fig. 37, the light receiving direction of the fingerprint detection device 362 is a direction 364, a direction 365, a direction 364 reverse direction, and a direction 365 reverse direction.

Alternatively, one skilled in the art may design the arrangement of the plurality of photo-sensing pixels based on the first direction or the second direction.

For example, the plurality of photo-sensing pixels form a rectangular array of photo-sensing pixels, and a projection of the first direction or the second direction onto the rectangular array of photo-sensing pixels is parallel to a diagonal direction of the rectangular array of photo-sensing pixels.

In some embodiments of the present application, the at least one microlens is one microlens, the plurality of optical sensing pixels are first column optical sensing pixels in a 2x2 optical sensing pixel matrix array, the one microlens is located above a center position of the 2x2 optical sensing pixel matrix array, and second column optical sensing pixels of the 2x2 optical sensing pixel matrix array are multiplexed to optical sensing pixels in first column optical sensing pixels in other fingerprint detection units. Optionally, two fingerprint detection units in the fingerprint detection device, which are adjacent in the row direction of the 2x2 matrix array of optical sensing pixels, are offset by one optical sensing pixel in the arrangement direction of the first column of optical sensing pixels in the 2x2 matrix array of optical sensing pixels.

In other words, the plurality of optical sensing pixels are rectangular arrays of 2x2 optical sensing pixels, the openings of the at least one light blocking layer enable the first row and the first column of optical sensing pixels and the second row and the second column of optical sensing pixels in the rectangular arrays of 2x2 optical sensing pixels to receive oblique light signals along one diagonal direction of the rectangular arrays of 2x2 optical sensing pixels, and the openings of the at least one light blocking layer enable the first row and the second column of optical sensing pixels and the second row and the first column of optical sensing pixels in the rectangular arrays of 2x2 optical sensing pixels to receive oblique light signals along the other diagonal direction of the rectangular arrays of 2x2 optical sensing pixels.

For example, as shown in fig. 38, the fingerprint detection unit 26 may include one microlens 262 and the left two optical sensing pixels 261 of the 4 optical sensing pixels 261 distributed in a rectangular array, wherein the left two optical sensing pixels 261 are used for receiving oblique optical signals in two directions converged by the one microlens 262. At this time, as shown in fig. 38, the fingerprint detection unit 26 may include a top light blocking layer and a bottom light blocking layer in terms of the light path design. The top light blocking layer may include two openings 262 corresponding to the left two optical sensing pixels 261, and the bottom light blocking layer may include two openings 263 corresponding to the left two optical sensing pixels 261. Alternatively, two openings 262 in the top light blocking layer may be merged into one large hole.

In other words, the at least one microlens is one microlens, the plurality of optical sensing pixels are two optical sensing pixels, the one microlens is located above the symmetry axes of the two optical sensing pixels, and the aperture of the at least one light blocking layer enables the two optical sensing pixels to respectively receive oblique light signals in two directions. For example, the one microlens is located above the center position of the long sides of the two photo-sensing pixels. Optionally, two adjacent fingerprint detection units in the fingerprint detection device are staggered by one optical sensing pixel in the arrangement direction of the two optical sensing pixels, so as to reasonably design a micro lens in the fingerprint detection device.

For example, as shown in fig. 39, each fingerprint detection unit in the fingerprint detection device may comprise one microlens 262 and two optical sensing pixels 261 corresponding to the one microlens.

In other words, the at least one microlens is three microlenses, a first microlens of the three microlenses being located above a center position of the rectangular array of 2x2 photo-sensing pixels, a second microlens of the three microlenses being located above an angle of a first row and a second column of the array of 2x2 photo-sensing pixels away from the center position, a third microlens of the three microlenses being located above an angle of a second row and a second column of the array of 2x2 photo-sensing pixels away from the center position, the second microlens or the third microlens being multiplexed as a first microlens of an adjacent fingerprint detection unit.

For example, as shown in fig. 40, each fingerprint detection unit in the fingerprint detection device may include three microlenses 262 and four photo-sensing pixels 261 (i.e., a 2x2 array of photo-sensing pixels 261) distributed in an array corresponding to the three microlenses 262. Wherein one microlens 262 of the three microlenses 262 is located over the center position of the array of 2x2 photo-sensing pixels 261; the other two microlenses 262 of the three microlenses 262 are disposed over adjacent two of the four corners of the 2x2 array of photo-sensing pixels 261. The microlenses 262 located above the center position are used to converge the received light signals to the optical sensing pixels 261 to which the other two corners of the four corners belong, and the other two microlenses 262 are respectively used to converge the received light signals to the optical sensing pixels 261 to which the two corners belong.

Alternatively, the other two microlenses 262 may be multiplexed as microlenses above the center position of the optical sensing pixel array in other fingerprint detection units.

The fingerprint detection device may comprise a plurality of fingerprint detection units (e.g. the fingerprint detection units shown in fig. 38 to 40), and the size of the fingerprint detection device may be reduced by rationally designing the arrangement between the plurality of fingerprint detection units.

For example, as shown in fig. 41, the fingerprint detection device may comprise a plurality of complete fingerprint detection units and a plurality of incomplete fingerprint detection units. The incomplete fingerprint detection unit comprises a micro lens and an optical sensing pixel. In other words, as shown in fig. 42, the fingerprint detection device may comprise a plurality of photo sensing pixels for receiving oblique light signals in direction 1 and a plurality of photo sensing pixels for receiving oblique light signals in direction 2, wherein "1" and "2" respectively denote photo sensing pixels for receiving two different directions. That is, the optical sensing pixels denoted by "1" and "2" may be used to generate one fingerprint image, that is, two fingerprint images may be generated in total, and the two fingerprint images may be used to combine into one high-resolution fingerprint image, so as to improve the recognition effect of the fingerprint detection device. Further, for a complete fingerprint detection unit, two small-sized apertures for two optically sensitive pixels in the top light blocking layer may be merged into one large-sized aperture. Alternatively, as shown in fig. 43, the large-sized openings may be elliptical openings or other polygonal openings. Such as rectangular openings.

In order to receive the oblique signal light, a certain displacement is needed between the micro lens in the fingerprint detection unit and the photosensitive unit, and when the light receiving direction is a single direction, the photosensitive unit can be translated to a certain distance in a corresponding direction so that the signal light falls at the center of the photosensitive unit. For example, as shown in fig. 44, if the microlenses 371 in the fingerprint detection device 370 converge the oblique light signal in a single direction to the photo-sensing pixels 372, optionally, as shown in fig. 45, each microlens 371 in the fingerprint detection device 370 moves in the direction in which the side length of the photo-sensing pixels 372 is located. At this time, the offset range of the spot area 3721 is the length d1 of the side length of the photo-sensing pixel 372.

When the fingerprint detection device needs to receive oblique light rays in different directions at the same time, as shown in fig. 46, the micro lens 371 in the fingerprint detection device 370 can converge oblique light signals in one direction to the corresponding optical sensing pixels 372, and the other micro lens 373 can converge oblique light signals in the other direction to the corresponding optical sensing pixels 372. At this time, in one implementation, as shown in fig. 46, both the microlens 371 and the microlens 373 are disposed above the center position of the photo-sensing pixel 372 such that the signal light is spaced apart from the center position of the photo-sensing pixel 372 by a distance d2 at the irradiation position of the photo-sensing pixel 372. In another implementation, as shown in fig. 47, each microlens 371 and each microlens 373 in the fingerprint detection device 370 moves in a direction in which a diagonal of the optical sensing pixel 372 is located. At this time, the offset range of the spot area 3721 is the length d3 of the diagonal line of the photo-sensing pixel 372.

In other words, when the fingerprint detection device needs to receive oblique light rays in different directions simultaneously, in one implementation, each microlens in the fingerprint detection unit moves in the direction in which the diagonal of the photo-sensing pixel is located. In another implementation, the center position of the spot area in the fingerprint detection device is shifted along the direction in which the diagonal of the optically sensitive pixel is located. For example, the offset direction of the micro-lenses in the four-way and two-way light receiving schemes is 45 degrees from the side length of the photo-sensing pixels. When there is a certain offset between the spot area and the center position of the optical sensing pixel, the tolerance of the offset is higher when the spot area moves in the diagonal direction of the optical sensing pixel compared with the offset of the spot area moving horizontally or vertically.

In some embodiments of the present application, the at least one microlens is one microlens, the plurality of optical sensing pixels are a first row first column optical sensing pixel and a fourth row first column optical sensing pixel of a first column optical sensing pixel in a 4x2 optical sensing pixel matrix array, the one microlens is located above a center position of a second column optical sensing pixel in the 4x2 optical sensing pixel matrix array, which is far from a side length of the first column optical sensing pixel, and the optical sensing pixels in the 4x2 optical sensing pixel matrix array except for the first row first column optical sensing pixel and the fourth column optical sensing pixel are multiplexed into optical sensing pixels in other fingerprint detection units. Optionally, two fingerprint detection units in the fingerprint detection device that are adjacent in the row direction of the 4x2 matrix array of optical sensing pixels are offset by one optical sensing pixel in the column direction of the 4x2 matrix array of optical sensing pixels. For example, in connection with fig. 48, the first column optical sensing pixels of the second row in the 4x2 optical sensing pixel matrix array may be multiplexed into the first column optical sensing pixels of the first row in the adjacent fingerprint detection units in the row direction.

For example, as shown in fig. 48, the fingerprint detection unit 27 includes a microlens 272, two photo-sensing pixels 271 (i.e., an upper left corner photo-sensing pixel 271 and a lower left corner photo-sensing pixel 271 in a 4x2 matrix array of photo-sensing pixels 271). Wherein the two openings 274 in the top light blocking layer corresponding to the two photo-sensing pixels 271 and the two openings 273 in the bottom light blocking layer corresponding to the two photo-sensing pixels 271 cause the microlenses 272 to converge the received light signals to the two photo-sensing pixels 271.

In other words, the at least one microlens is three microlenses, the plurality of optical sensing pixels are first columns of optical sensing pixels in the 4x2 optical sensing pixel matrix array, and the three microlenses are uniformly distributed over a side of a second column of optical sensing pixels in the 4x2 optical sensing pixel matrix array, which is far from the first column of optical sensing pixels. Optionally, two fingerprint detection units in the fingerprint detection device, which are adjacent in the row direction of the 4x2 matrix array of optical sensing pixels, are offset by one optical sensing pixel in the arrangement direction of the first column of optical sensing pixels in the 4x2 matrix array of optical sensing pixels.

For example, as shown in fig. 49, one microlens 272 of the three microlenses is located above a center position of a second column of the 4x2 array of the optical sensing pixels, which is away from a side length of the first column of the optical sensing pixels, and the other two microlenses 272 of the three microlenses are respectively located above two ends of the second column of the 4x2 array of the optical sensing pixels, which are away from the side length of the first column of the optical sensing pixels.

In other words, the at least one microlens is four microlenses, the plurality of optical sensing pixels is a 2x2 optical sensing pixel matrix array, the optical sensing pixels in the 2x2 optical sensing pixel rectangular array are located at first and second column positions in second and third rows of the 4x3 optical sensing pixel rectangular array, two microlenses among the four microlenses are respectively located above two corners of four corners of the 2x2 optical sensing pixel rectangular array, which are close to a third column of the 4x3 optical sensing pixel rectangular array, and the other two microlenses are respectively located above two corners of four corners of the 4x3 optical sensing pixel rectangular array, which are far from a center position of the 2x2 optical sensing pixel rectangular array, along a diagonal direction of the 2x2 optical sensing pixel rectangular array. Optionally, the optical sensing pixels in the 4x3 optical sensing pixel rectangular array except for the 2x2 optical sensing pixel rectangular array are multiplexed into optical sensing pixels in the 2x2 optical sensing pixel rectangular array for receiving oblique optical signals in the adjacent fingerprint detection units.

For example, as shown in fig. 50, the microlens 272 in the upper right corner converges the received light signal to the second row and second column of the optical sensing pixels 271 in the diagonal direction of the optical sensing pixels 271. The microlens 272 in the lower right corner condenses the received light signal to the third row and second column of the photo-sensing pixels 271 in the diagonal direction of the photo-sensing pixels 271. The microlens 272 in the upper left corner may converge the received light signal to the third row and first column of the photo-sensing pixels 271 in the diagonal direction of the photo-sensing pixels 271. The microlens 272 in the lower left corner may converge the received light signal to the second row and first column of the photo-sensing pixels 271 in the diagonal direction of the photo-sensing pixels 271.

Alternatively, the upper left microlens 272 converges the received light signal to the photo-sensing pixel 271 at other positions (for example, the third row and first column photo-sensing pixels 271) along the diagonal direction of the photo-sensing pixel 271.

In some embodiments of the present application, a plurality of rows of microlenses in a plurality of fingerprint detection units in the fingerprint detection device are distributed with respect to each other in a staggered manner. For example, the fingerprint detection device comprises a plurality of rows of microlenses, wherein two adjacent rows of microlenses are arranged in a staggered manner.

For example, as shown in fig. 51, the fingerprint detection device may comprise a plurality of complete and a plurality of incomplete fingerprint detection units as shown in fig. 48. The incomplete fingerprint detection unit comprises a micro lens and an optical sensing pixel. In other words, as shown in fig. 52, the optical sensing pixels adjacent to the optical sensing pixels for receiving the oblique light signal in the direction 1 in the fingerprint detection device are all a plurality of optical sensing pixels for receiving the oblique light signal in the direction 2, so that the optical sensing pixels in the optical sensing pixel array are uniformly distributed, and the recognition effect of the fingerprint detection device is improved. Further, for a complete fingerprint detection unit, two small-sized apertures for two optically sensitive pixels in the top light blocking layer may be merged into one large-sized aperture. Alternatively, as shown in fig. 53, the large-sized openings may be elliptical openings or other polygonal openings. Such as rectangular openings.

As another example, as shown in fig. 54, the fingerprint detection device may comprise 4 fingerprint detection units as shown in fig. 50. Alternatively, as shown in fig. 55, the optically sensing pixels for receiving oblique light signals in two directions among the four fingerprint detection units may be distributed in an array. Alternatively, as shown in fig. 56, two adjacent fingerprint detection units may share one microlens (i.e., a common microlens) corresponding to one large-sized aperture in the at least one light blocking layer.

In some embodiments of the application, the plurality of photo-sensing pixels is a rectangular array of 4x4 photo-sensing pixels, the rectangular array of 4x4 photo-sensing pixels comprising 4 rectangular arrays of 2x2 photo-sensing pixels distributed in an array, wherein, the first column, the first row, the second row and the second column of the 4x4 optical sensing pixel rectangular array are used for receiving oblique light signals in one direction, and the first column, the second row and the first column of the 4x4 optical sensing pixel rectangular array are used for receiving oblique light signals in the other direction, and the first column, the second row and the first column of the 2x2 optical sensing pixel rectangular array are used for receiving oblique light signals in the other direction.

In other words, the microlens corresponding to the same photo-sensing pixel is shifted in the opposite direction of the oblique light direction received by each photo-sensing pixel in the fingerprint detection unit. Alternatively, when there is an overlap in positions after the microlenses corresponding to the plurality of optical sensing pixels are shifted, the microlenses corresponding to the plurality of optical sensing pixels may be combined into one large-sized microlens. For example, when the positions of the micro lenses corresponding to the plurality of photo sensing pixels after the shifting completely overlap, the plurality of photo sensing pixels may directly correspond to one micro lens. Optionally, when the plurality of optical sensing pixels correspond to one microlens, the plurality of small-size openings corresponding to the plurality of optical sensing pixels in the top light blocking layer of the at least one light blocking layer may be combined into one large-size opening. Optionally, a top light blocking layer of the at least one light blocking layer is provided with an opening corresponding to each optical sensing pixel.

As an example, the at least one microlens includes one rectangular 3x2 microlens array and two rectangular 2x2 microlens arrays, the rectangular 3x2 microlens arrays are located above the first to third columns of the rectangular 4x4 photo-sensing pixels, the two rectangular 2x2 microlens arrays are respectively located above the first and fourth rows of the rectangular 4x4 photo-sensing pixels, the four microlenses of each rectangular 2x2 microlens array of the two rectangular 2x2 microlens arrays are respectively located above the four corners of the corresponding photo-sensing pixels, so that the first row 2x2 photo-sensing pixels of the rectangular 4x4 photo-sensing pixels and the second row 2x2 photo-sensing pixels of the rectangular 4x4 photo-sensing pixels receive oblique light signals in one diagonal direction of the rectangular 4x4 photo-sensing pixels and the second row 2x2 photo-sensing pixels of the rectangular 4x4 photo-sensing pixels receive oblique light signals in the other diagonal direction of the rectangular 4x4 photo-sensing pixels. Optionally, the microlenses of the two 2x2 microlens rectangular arrays located above the side length of the 4x4 optical sensing pixel rectangular array are multiplexed into the microlenses of the other fingerprint detection units.

For example, as shown in fig. 57, an array of photo-sensing pixels 281 in the fingerprint detection unit 28 is used to receive oblique light signals in two diagonal directions of the array. Each of the micro lenses 282 of the fingerprint detection unit 28 is moved a distance in the opposite direction of the converged oblique optical signal. For example, the certain distance may be half the length of the diagonal line of the photo-sensing pixel 281. Wherein each light blocking layer in the fingerprint detection unit 28 may be provided with an aperture for each photo-sensing pixel 281. In other words, as shown in fig. 58, the fingerprint detection device may include 42 x2 photo-sensing pixel arrays distributed in an array, wherein the 2x2 photo-sensing pixel arrays in two diagonal directions are respectively used for receiving oblique light signals in two directions. Alternatively, as shown in fig. 59, when the plurality of photo-sensing pixels 281 corresponds to one microlens 282, one large-sized opening may be provided for the plurality of photo-sensing pixels 281 in the top light blocking layer of the at least one light blocking layer. Alternatively, as shown in fig. 60, the photo-sensing pixels 281 in the plurality of fingerprint detection units 28 are continuously distributed in an array.

As another example, each of the rectangular arrays of 4x4 photo-sensing pixels is configured to receive light signals converged by a microlens over an adjacent photo-sensing pixel such that a first column, a first row, a second row, a first column, a second row, a second column, a rectangular array of 2x2 photo-sensing pixels in the rectangular array of 4x4 photo-sensing pixels receive oblique light signals in a direction in which one side of the rectangular array of 4x4 photo-sensing pixels is located, and the first column second row 2x2 rectangular array of optical sensing pixels in the 4x4 rectangular array of optical sensing pixels receive oblique optical signals in the direction of the other side length adjacent to the one side length. Optionally, the method is characterized in that a microlens above an outer area of the 4x4 optical sensing pixel rectangular array in the at least one microlens is multiplexed into microlenses in other fingerprint detection units.

For example, as shown in fig. 61, an array of photo-sensing pixels 281 in the fingerprint detection unit 28 is used to receive oblique light signals in two adjacent side length directions of the array. Each of the micro lenses 282 of the fingerprint detection unit 28 is moved a distance in the opposite direction of the converged oblique optical signal. For example, the certain distance may be the length of the side length of the photo-sensing pixel 281. Wherein each light blocking layer in the fingerprint detection unit 28 may be provided with an aperture for each photo-sensing pixel 281. Alternatively, as shown in fig. 62, the fingerprint detection device may comprise a plurality of fingerprint detection units 28, wherein the optical sensing pixels 281 in the plurality of fingerprint detection units 28 are continuously distributed in an array.

In some embodiments of the present application, the plurality of photo-sensing pixels are a plurality of rows of photo-sensing pixels, at least one row of first photo-sensing pixels in the plurality of rows of photo-sensing pixels is configured to receive a tilted light signal in one direction, and at least one row of second photo-sensing pixels in the plurality of rows of photo-sensing pixels is configured to receive a tilted light signal in another direction.

In other words, when the fingerprint detection device comprises a plurality of fingerprint detection units distributed in an array, the fingerprint detection device comprises an array of optically sensitive pixels distributed in an array, at least one row or column of the array of optically sensitive pixels is used for receiving oblique light signals in one direction, and the remaining rows or columns are used for receiving oblique light signals in the other direction.

As an example, each of the plurality of rows of photo-sensing pixels is configured to receive the light signal converged by the microlens above the adjacent photo-sensing pixel such that the at least one row of first photo-sensing pixels receives the oblique light signal along the arrangement direction of the photo-sensing pixels and the at least one row of second photo-sensing pixels receives the oblique light signal along the perpendicular direction of the arrangement direction of the photo-sensing pixels.

For example, as shown in fig. 63, the fingerprint detection unit 29 comprises an array of 4x4 photo-sensing pixels 291, each photo-sensing pixel 291 in the array of 4x4 photo-sensing pixels 291 being adapted to receive light signals converged by a microlens 292 above an adjacent photo-sensing pixel 291. The bottom light blocking layer of the at least one light blocking layer is provided with an aperture 264 corresponding to each photo-sensing pixel 291, and the top light blocking layer of the at least one light blocking layer is provided with an aperture 263 corresponding to each photo-sensing pixel 291. In other words, as shown in fig. 64, the first and second rows of the fingerprint detection unit 29 are configured to receive oblique light signals in the horizontal direction, and the third and fourth rows of the fingerprint detection unit 29 are configured to receive oblique light signals in the vertical direction.

As another example, the at least one microlens is a rectangular array of 3x1 microlenses, the plurality of photo-sensing pixels are the first column of photo-sensing pixels in a rectangular array of 4x2 photo-sensing pixels, the rectangular array of 3x1 microlenses is located above the rectangular array of 4x2 photo-sensing pixels, and the second column of photo-sensing pixels in the rectangular array of 4x2 photo-sensing pixels are multiplexed to photo-sensing pixels in other fingerprint detection units.

For example, as shown in fig. 65, the first and second rows of optical sensing pixels 291 of the 3x1 microlens rectangular array receive an optical signal in one diagonal direction through three microlenses 292, the third and fourth rows of optical sensing pixels 291 of the 3x1 microlens rectangular array receive an optical signal in another diagonal direction, and similarly, the top light blocking layer of the at least one light blocking layer is provided with four openings 294 corresponding to the 3x1 microlens rectangular array, and the bottom light blocking layer of the at least one light blocking layer is provided with four openings 293 corresponding to the 3x1 microlens rectangular array. Alternatively, the fingerprint detection device may comprise a plurality of fingerprint detection units 29 distributed in an array. For example, as shown in fig. 66, the fingerprint detection device may comprise 4 fingerprint detection units 29. Alternatively, as shown in fig. 67, one large-sized opening is formed in the top light blocking layer corresponding to the second and third rows of optical sensing pixels 291 in the rectangular array of 3x1 micro lenses.

The above description has been made regarding the structure of the fingerprint detection unit or the fingerprint detection device, for example, the structure of the fingerprint detection unit or the fingerprint detection device is desirably constructed based on the transmission of the optical signal, and in the manufacturing process, mass production is required based on specific design parameters, and the specific design parameters of the fingerprint detection device are exemplified below.

Fig. 68 is a schematic structural diagram of a fingerprint detection device according to an embodiment of the present application, and for ease of understanding, the following structural diagram 68 describes design parameters of the fingerprint detection device.

As an example, a fingerprint detection device comprises a microlens array, Z light blocking layers below the microlens array, and an optically sensitive pixel array below the Z light blocking layers, Z being a positive integer. The micro lens array is used for being arranged below the display screen; z light blocking layers are arranged below the micro lens array, and each light blocking layer of the Z light blocking layers is provided with a small hole array; the optical sensing pixel array is arranged below the aperture array of the bottom light blocking layer in the Z light blocking layers.

It should be understood that the fingerprint detection device and the microlens array, the Z light blocking layers, and the optical sensing pixel array in the fingerprint detection device may be referred to in the above description, and are not repeated here for avoiding repetition.

As shown in fig. 68, the microlens array may include a plurality of microlenses 411, the Z light blocking layers may include a top light blocking layer 412, a middle light blocking layer 413, and a bottom light blocking layer 414, and the photo sensing pixel array may include a plurality of photo sensing pixels 415.C represents the maximum caliber of a single microlens, and if square or other shaped microlenses, C may be the maximum length of the microlens cross-section in the periodic direction. P represents the period of the microlens. H denotes the height of an individual microlens, i.e., the height of the microlens apex to the top of the planar layer. D ₁、D₂、D₃ denotes the small hole maximum aperture, i.e., the size at the maximum caliber of the opening, in the bottom light-blocking layer 414, the middle light-blocking layer 413, and the top light-blocking layer 412, respectively. X ₁、X₂、X₃ represents the amounts of offset of the center positions of the openings in the bottom light-blocking layer 414, the middle light-blocking layer 413, and the top light-blocking layer 412 and the center positions of the corresponding microlenses on the plane in which the microlens array is located, respectively. Z ₁、Z₂、Z₃ represents distances between the bottom light-blocking layer 414, the middle light-blocking layer 413, and the top light-blocking layer 412, respectively, and the bottom (e.g., lower surface) of the microlens array.

The microlenses in the microlens array may be circular microlenses, i.e., FIG. 68 may be a side sectional view of the fingerprint detection device 40 shown in FIG. 69 along the E-E' direction. The microlenses in the microlens array may also be square microlenses. That is, FIG. 69 may be a side cross-sectional view of the fingerprint sensing device 40 shown in FIG. 70 taken along the direction F-F'. For example, the microlenses in the microlens array are circular microlenses, and the larger spacing between adjacent circular microlenses in the circular microlens matrix results in a smaller effective light receiving area, typically 60%; the microlenses in the square microlens matrix can be cut by passing a sphere through a cuboid form to obtain square microlenses, which can obtain a higher light receiving area ratio (for example, more than 98%) than the circular microlens matrix. Of course, the individual microlenses may be other shapes as well in order to achieve a high duty cycle.

Specific parameters of the fingerprint detection device are designed as shown in fig. 68.

In some embodiments of the present application, the aperture array of each of the Z light blocking layers satisfies 0+.x _i/Z_d +.3, so that after the light signal returned from the finger above the display screen is converged by the microlens array, the light signal is transmitted to the optical sensing pixel array through the aperture array provided in the Z light blocking layers, and the light signal is used to detect fingerprint information of the finger. Z _d represents the vertical distance between the bottom light-blocking layer and the microlens array, X _i represents the distance between the first center and the second center projected on the plane of the microlens array, the first center being the center of a microlens in the microlens array, and the second center being the center of an aperture in the ith light-blocking layer of the Z light-blocking layers for transmitting the optical signal converged by the microlens. For example, Z _d represents a vertical distance between a lower surface of the underlying light-blocking layer and a lower surface of the microlens array. For another example, Z _d represents the vertical distance between the upper surface of the underlying light-blocking layer and the lower surface of the microlens array. For example, the array of small holes of each of the Z light-blocking layers satisfies 0.ltoreq.X _i/Z_d.ltoreq.3/2. For another example, the array of apertures of each of the Z light-blocking layers satisfies 1/2.ltoreq.X _i/Z_d.ltoreq.3/2.

The ith light blocking layer may be an ith light blocking layer from top to bottom, or an ith light blocking layer from bottom to top.

By restraining the structural parameters of the small holes in the small hole array, the optical signals returned from different positions of the finger can be prevented from being sent and aliased, namely, the brightness of the fingerprint image is improved on the basis of ensuring the contrast of the fingerprint image, the signal-to-noise ratio and the resolution ratio of the fingerprint image are increased, and the fingerprint identification effect and the identification accuracy are improved.

It should be noted that, the structural parameter X _i/Z_d of the small holes in the small hole array is the distance between the first center and the second center, and may be divided into three parameters in a space rectangular coordinate system. For example, the center position of each of the microlens arrays may be taken as the origin, the direction in which the rows of the microlens arrays are located may be taken as the X axis, the direction in which the columns of the microlens arrays are located may be taken as the Y axis, and the direction perpendicular to the X-Y plane may be taken as the Z axis. At this time, the aperture parameter X _i may be replaced with the position of the aperture in the X-Y coordinate system, and the aperture parameter Z _d may be replaced with the parameters of the apertures in the aperture array in the Z-axis direction. For another example, the spatial position of each aperture in the aperture array may be determined using the center position of the microlens array as the origin.

It should be further noted that, for the relevant parameters of the wells in the well array, since one microlens may transmit the converged light signal to the corresponding optical sensing pixel through a plurality of wells, one microlens may correspond to a plurality of parameters X _i/Z_d. In addition, since a plurality of microlenses may transmit the converged optical signal to the corresponding optical sensing pixel through one aperture, similarly, one aperture may correspond to a plurality of parameters X _i/Z_d, in other words, the spatial structure of one aperture may be designed by a plurality of parameters X _i/Z_d.

In some embodiments of the present application, the maximum aperture of the apertures in the aperture array in the underlying light blocking layer needs to be greater than a first preset value and less than a second preset value.

For example, the apertures in the array of apertures in the underlying light blocking layer satisfy 0um < D _d.ltoreq.6 um, where D _d represents the maximum aperture of the apertures in the array of apertures in the underlying light blocking layer. For example, the apertures in the aperture array in the underlying light blocking layer satisfy 0.5um < D _d.ltoreq.5 um. For another example, the apertures in the aperture array in the underlying light blocking layer satisfy 0.4um < D _d.ltoreq.4 um.

The greater the image contrast of the fingerprint image obtained by aperture imaging, the smaller the brightness (i.e. the brightness of the aperture), and correspondingly the greater the brightness, the smaller the image contrast.

In some embodiments of the present application, each microlens in the microlens array may satisfy the formula 0< H/C.ltoreq.1, where H represents the maximum thickness of the microlenses in the microlens array and C represents the maximum caliber of the microlenses in the microlens array. For example, each microlens in the microlens array satisfies 0< H/C.ltoreq.1/2. As another example, each microlens in the microlens array satisfies 0.2 < H/C.ltoreq.0.4.

The maximum aperture of the microlens may be the maximum width of a cross section having the largest area of the microlens. For example, the microlens is a hemispherical lens, and the maximum aperture of the microlens may be the maximum width of the plane of the hemispherical lens.

In other words, each microlens in the microlens array is a hemispherical microlens, and the curvature of each microlens in the microlens array is less than or equal to 0.5.

When fingerprint images are acquired through pinhole imaging, it is necessary to ensure that spherical aberration of the microlenses in the microlens array does not affect imaging quality. In this embodiment, by restricting the ratio between the maximum thickness and the maximum caliber of the microlens, on the basis of the miniaturized fingerprint detection device, the microlens can be ensured to focus the converged optical signal in the aperture of the bottom light blocking layer, thereby ensuring the imaging quality of the fingerprint image. In other words, by restricting the ratio of H to C, on the basis of ensuring that the fingerprint detection device has a smaller thickness, the spherical aberration of the microlens array is reduced, thereby ensuring the fingerprint identification effect.

In some embodiments of the present application, 0 um.ltoreq.Z _d.ltoreq.100 um is satisfied between the underlying light blocking layer and the microlens array. For example, 2 um.ltoreq.Z _d.ltoreq.50 um is satisfied between the underlying light blocking layer and the microlens array. For another example, 3 um.ltoreq.Z _d.ltoreq.40 um is satisfied between the underlying light blocking layer and the microlens array.

By constraining the parameters between the underlying light blocking layer and the microlens array, the thickness of the fingerprint detection device can be effectively reduced. Of course, the maximum distance or the minimum distance between each of the Z light blocking layers and the microlens array may also be constrained, which all belong to the technical solution protected by the embodiment of the present application.

In some embodiments of the application, the microlens array satisfies 0um < P.ltoreq.100 um. For example, the microlens array satisfies 2 um.ltoreq.P.ltoreq.50um. For another example, the microlens array satisfies 1 um.ltoreq.P.ltoreq.40 um. Wherein P represents the period of the microlenses in the microlens array.

In other words, the distance between the center positions of two adjacent microlenses in the microlens array satisfies 0um < P.ltoreq.100 um, i.e., P may also be used to represent the distance between the center positions of two adjacent microlenses in the microlens array.

By constraining the period of the microlens array, not only is it convenient to produce the microlens array alone, but it is also advantageous to spatially match the optically sensitive pixel array so as to obtain an optical fingerprint image having the desired resolution.

In some embodiments of the present application, the small holes in the array of small holes in each of the Z light-blocking layers and the micro lenses in the array of micro lenses satisfy 0 < D _i/P.ltoreq.3, where D _i represents the aperture of the small holes in the array of small holes in the ith light-blocking layer of the Z light-blocking layers, and P represents the period of the micro lenses in the array of micro lenses. For example, the small holes in the small hole array in each of the Z light blocking layers and the micro lenses in the micro lens array satisfy 0 < D _i/P.ltoreq.2. For another example, the small holes in the small hole array in each of the Z light blocking layers and the micro lenses in the micro lens array satisfy 1 < D _i/P.ltoreq.4.

In other words, one aperture in the array of apertures in the fingerprint detection device may correspond to one microlens or a plurality of microlenses. I.e. one or more micro-lenses may transmit optical signals through one of the array of apertures to a corresponding optically sensitive pixel.

Aiming at the microlens array and the aperture array distributed in the array, the design of the light path parameters can be effectively simplified through the parameters D _i/P.

In some embodiments of the application, the microlens array satisfies 0 < C/P.ltoreq.1, where C represents the maximum aperture of the microlenses in the microlens array and P represents the period of the microlenses in the microlens array.

The duty ratio of the micro lens array can be increased by restraining the ratio between C and P, so that the fingerprint detection device is ensured to have smaller volume.

In some embodiments of the present application, the Z light-blocking layers satisfy 0.ltoreq.Z _i/Z_d.ltoreq.1, where Z _i represents a vertical distance between an i-th light-blocking layer of the Z light-blocking layers and the microlens array, and Z _d represents a vertical distance between the underlying light-blocking layer and the microlens array. For example, the Z light blocking layers satisfy 0.ltoreq.Z _i/Z_d.ltoreq.0.5.

In other words, by specifying the parameter Z _i/Z_d, the design parameters of the Z light-blocking layers can be simplified, so that the mounting efficiency of the Z light-blocking layers can be improved in the mass production process.

The following are examples of specific values of the above parameters.

TABLE 1

Parameters (parameters)	Example one	Example two	Example three	Example four	Example five	Example six	Example seven	Example eight	Example nine
										P	16.88	10.45	22.50	8.75	7.86	18.14	12.50	13.63	11.50
C	15.53	9.61	22.50	8.75	7.86	16.68	9.09	12.54	10.58
										H	4.37	1.71	6.55	2.76	3.17	3.63	2.06	1.96	2.47
D1	1.38	2.17	5.30	1.62	1.59	4.30	2.59	2.41	1.71
										D2	13.51	4.01	7.47	3.12	4.09	6.50	5.81	7.97	12.22
D3	Without any means for	9.44	Without any means for	Without any means for	Without any means for	17.33	Without any means for	13.47	Without any means for
										X1	0.00	0.00	0.00	0.00	11.91	10.68	9.13	8.64	8.19
X2	0.00	0.00	0.00	0.00	9.93	6.85	3.10	3.40	2.79
										X3	Without any means for	0.00	Without any means for	Without any means for	Without any means for	0.00	Without any means for	2.00	Without any means for
Z1	18.13	19.90	27.34	11.79	12.78	25.43	21.45	23.74	22.20
										Z2	1.79	16.25	15.44	8.41	7.74	20.90	13.30	15.24	14.99
Z3	Without any means for	0.75	Without any means for	Without any means for	Without any means for	1.72	Without any means for	10.86	Without any means for

As shown in table 1, the fingerprint detection device may be provided with two light blocking layers (i.e., the light blocking layers associated with Z1 and Z2) or may be provided with three light blocking layers (i.e., the light blocking layers associated with Z1, Z2 and Z3), and of course, the number of light blocking layers provided may be one or more than three, which is not particularly limited in the present application.

Based on the values of the parameters of table 1, table 2 exemplarily shows the structural parameters of the fingerprint detection device designed by the ratio of the two parameters.

TABLE 2

The structure of the fingerprint detection device may also be designed using the ratio of the two parameters referred to above, as shown in table 2. It should be noted that the embodiments of the present application are not limited to the specific values described above, and those skilled in the art may determine the specific values of each parameter according to the actual optical path design requirements. For example, the above parameters may be accurate to a three-digit number or a four-digit number after the decimal point.

In some embodiments of the present application, the fingerprint detection device may include a plurality of fingerprint detection units distributed in an array or staggered, and a center position of a photosensitive area of each of a plurality of optical sensing pixels in each of the plurality of fingerprint detection units is offset from a center position of the same optical sensing pixel.

In other words, the center position of the photosensitive area of each of the plurality of photo-sensing pixels and the center position of the same photo-sensing pixel do not coincide. Alternatively, the photosensitive areas of the fingerprint detection device are arranged periodically in units of fingerprint detection units, rather than in units of optical sensing pixels.

The center position of the photosensitive area of each of the plurality of optical sensing pixels is offset relative to the center position of the same optical sensing pixel, so that the image distance of one micro lens can be increased under the condition that the vertical distance between the micro lens and the plurality of optical sensing pixels is fixed, and the thickness of the fingerprint detection device can be reduced.

In other words, with the fingerprint detection device, by receiving the optical signals of a plurality of inclination angles and shifting the center position of the photosensitive area of the optical sensing pixel, the thickness of the fingerprint detection device can be reduced as much as possible.

It should be understood that the photo-sensing pixel in the present application may refer to a region where a photosensitive device is provided on a substrate, and the photosensitive region of the photo-sensing pixel refers to a region where an oblique light signal can be directed to the photo-sensing pixel through an opening in at least one light blocking layer, in other words, the photosensitive region may also refer to a region in the photo-sensing pixel that can be illuminated through an opening in a light blocking layer in a fingerprint detection unit, and the sensing region is also referred to as a spot region.

In some embodiments of the application, a distance between a center position of each of the plurality of photo-sensing pixels and a center position of the one microlens is smaller than a distance between a center position of a photosensitive region of the same photo-sensing pixel and a center position of the one microlens.

In other words, the center position of the photosensitive area of each of the plurality of photo-sensing pixels is shifted from the center position of the same photo-sensing pixel, and the distance between the center position of the photosensitive area of each of the plurality of photo-sensing pixels and the center position of the one microlens can be increased.

Thus, the image distance of the one microlens can be increased while maintaining the vertical distance between the one microlens and the plurality of photo-sensing pixels unchanged.

In some embodiments of the present application, a light spot area is formed on the light sensing area of each of the plurality of optical sensing pixels through an opening provided in the at least one light blocking layer, a central position of the light spot area is offset by a first distance with respect to a projection of a central position of the one microlens on a plane where the plurality of optical sensing pixels are located, a line between the central position of the one microlens and the central position of the light spot area forms a first angle with a direction perpendicular to the display screen, and the first distance is inversely proportional to a remainder of the first angle.

The first included angle may be an angle of refraction of light when the light enters the fingerprint detection unit or an optical path medium of the fingerprint detection unit from air, and the optical path medium may include the one microlens and a transparent medium between the one microlens and the plurality of optical sensing pixels.

In other words, the first angle of incidence may be an oblique angle of incidence in the fingerprint detection unit or in the optical path medium of the fingerprint detection unit.

Alternatively, the first included angle may be an included angle between an oblique optical signal transmitted in the fingerprint detection unit or an optical path medium of the fingerprint detection unit and a direction perpendicular to the display screen.

As an example, the spot area is smaller than a photosensitive area of each of the plurality of photo-sensing pixels, and the spot area is disposed on a side of the photosensitive area that is closer to or farther from the one microlens. Of course, the spot area may also be disposed at the center of the photosensitive area.

In some embodiments of the application, the vertical distance between the one microlens and the plurality of optically sensitive pixels is equal to the product of the first angle cotangent and the first distance.

In other words, the vertical distance may be determined by the formula h=x×cotθ. Wherein h is the vertical distance, x is the first distance, and θ is the first angle. The vertical distance may also be referred to as the light path height of the fingerprint detection unit.

Thereby, it can be ensured that the one microlens images the optical signal returned via the finger to the plurality of optical sensing pixels to form a fingerprint image.

In other words, setting the vertical distance to be the product of the cotangent of the first included angle and the first distance may cause the one microlens to image oblique optical signals in multiple directions to the photosensitive region where the shift occurs.

Taking an optical signal with an oblique incidence angle (i.e. the first included angle) of 26 ° in air as an example, assume that parameters of a fingerprint detection unit in the fingerprint detection device are as follows:

The plurality of optical sensing pixels are located below the micro-lens, the plurality of optical sensing pixels are 2x2 optical sensing pixel rectangular arrays, each optical sensing pixel in the 2x2 optical sensing pixel rectangular arrays is a rectangular pixel, the side length of each optical sensing pixel is 7.5um, the center position of the photosensitive area of each optical sensing pixel in the 2x2 optical sensing pixel rectangular arrays is 5um away from the center position of the 2x2 optical sensing pixel rectangular arrays, and the oblique incidence angle (namely the first included angle) of the optical path medium of the fingerprint detection unit is about 19 degrees.

At this time, if the period of the micro lens in the fingerprint detection device is 15um and the center position of the photosensitive area is offset, the thickness of the optical path of the fingerprint detection unit is about 20 um.

Meanwhile, if the period of the micro lens in the fingerprint detection device is 7.5um, (i.e. the micro lens corresponds to the optical sensing pixels one by one), and the center position of the photosensitive area is not shifted, the optical path of the fingerprint detection unit needs 40um, and the processing difficulty increases exponentially.

Therefore, the fingerprint detection device is thinner in light path thickness in the scheme of uniformly distributing the fingerprint detection device relative to the photosensitive area.

In a specific implementation, the angle (i.e., the first angle) and the direction of the oblique optical signals to be received by the plurality of optical sensing pixels can be reasonably designed by adjusting at least one of the offset of the central position of the photosensitive region, the position of the light spot region in the photosensitive region, the position of the bottom light blocking layer of the at least one light blocking layer, the setting position of the opening in the at least one light blocking layer, the curvature radius of the micro lens and the light path height of the fingerprint detection unit.

In some embodiments of the present application, the center position of the photosensitive area of each of the plurality of photo-sensing pixels is offset from the center position of the same photo-sensing pixel in a direction away from or toward the center position of the plurality of photo-sensing pixels.

In other words, the person skilled in the art may determine the first distance based on the first angle and the vertical distance, and further determine the positional relationship between the one microlens and the plurality of optical sensing pixels based on the first distance. For example, the plurality of photo-sensing pixels are located below the one microlens. For another example, the plurality of photo-sensing pixels are respectively located under a plurality of microlenses adjacent to the one microlens.

For example, the plurality of photo-sensing pixels are disposed under the one microlens, and a center position of a photosensitive region of each of the plurality of photo-sensing pixels is offset from a center position of the same photo-sensing pixel in a direction away from the center positions of the plurality of photo-sensing pixels.

In other words, assuming that each of the plurality of photo-sensing pixels is a rectangular pixel, after determining the first distance based on the first angle and the vertical distance, the skilled person will indicate that the one microlens may collect the received oblique light signal to the photosensitive area of the plurality of photo-sensing pixels under the one microlens if the first distance is smaller than the length of the hypotenuse of the rectangular pixel.

At this time, an offset distance of the center position of the photosensitive area of each of the plurality of photo-sensing pixels with respect to the center position of the same photo-sensing pixel may be determined by the formula y=x-1/2L, where y represents the offset distance and y represents a positive number that the center position of the photosensitive area of each of the plurality of photo-sensing pixels is offset in a direction away from the center position of the same photo-sensing pixel with respect to the center position of the same photo-sensing pixel. y is a negative number indicating that the center position of the photosensitive area of each of the plurality of photo-sensing pixels is shifted from the center position of the same photo-sensing pixel in a direction approaching the center position of the plurality of photo-sensing pixels.

Of course, the offset distance of the center position of the photosensitive area of each of the plurality of photo-sensing pixels relative to the center position of the same photo-sensing pixel can also be determined by the formula y=x-1/2L-z, where z represents the offset distance of the center position of the spot area relative to the center position of the sensing area. And z is a positive number indicating a distance that the central position of the light spot area is offset in a direction away from the central positions of the plurality of optical sensing pixels relative to the central position of the sensing area, and z is a negative number indicating a distance that the central position of the light spot area is offset in a direction close to the central positions of the plurality of optical sensing pixels relative to the central position of the sensing area.

For another example, the plurality of photo-sensing pixels are respectively located below the plurality of microlenses adjacent to the first microlens, and a center position of a photosensitive area of each of the plurality of photo-sensing pixels is offset from a center position of the same photo-sensing pixel in a direction away from or toward the center position of the plurality of photo-sensing pixels.

In other words, assuming that each of the plurality of photo-sensing pixels is a rectangular pixel, after determining the first distance based on the first angle and the vertical distance, the skilled person may indicate that the one microlens may converge the received oblique light signal to the photosensitive area of the photo-sensing pixel under the plurality of microlenses adjacent to the one microlens if the first distance is greater than the length of the hypotenuse of the rectangular pixel.

At this time, an offset distance of the center position of the photosensitive area of each of the plurality of photo-sensing pixels with respect to the center position of the same photo-sensing pixel may be determined by the formula y=x-L, where y represents the offset distance and y represents a positive number that the center position of the photosensitive area of each of the plurality of photo-sensing pixels is offset in a direction approaching the center position of the plurality of photo-sensing pixels with respect to the center position of the same photo-sensing pixel. y is a negative number indicating that the center position of the photosensitive area of each of the plurality of photo-sensing pixels is offset from the center position of the same photo-sensing pixel in a direction away from the center position of the plurality of photo-sensing pixels.

Of course, the offset distance of the center position of the photosensitive area of each of the plurality of photo-sensing pixels from the center position of the same photo-sensing pixel can also be determined by the formula y=x-L-z, where z represents the offset distance of the center position of the spot area from the center position of the sensing area. And z is a positive number indicating a distance by which the center position of the spot area is shifted in a direction approaching the center positions of the plurality of optical sensing pixels relative to the center position of the sensing area, and z is a negative number indicating a distance by which the center position of the spot area is shifted in a direction separating from the center positions of the plurality of optical sensing pixels relative to the center position of the sensing area.

For example, the center position of the photosensitive area of each of the plurality of photo-sensing pixels is offset along the diagonal of the same photo-sensing pixel such that the center position of the photosensitive area of each of the plurality of photo-sensing pixels is located on the diagonal of the same photo-sensing pixel.

Taking the plurality of optical sensing pixels as a 2x2 optical sensing pixel rectangular array as an example, four photosensitive areas of the 2x2 optical sensing pixel rectangular array may be distributed on four corners of the 2x2 optical sensing pixel rectangular array.

For another example, the center position of the photosensitive area of each of the plurality of photo-sensing pixels is offset along the side length of the same photo-sensing pixel, such that a line connecting the center position of the photosensitive area of each of the plurality of photo-sensing pixels with the center position of the same photo-sensing pixel is parallel to the side length of the same photo-sensing pixel.

Taking the plurality of optical sensing pixels as a 2x2 optical sensing pixel rectangular array as an example, four photosensitive areas of the 2x2 optical sensing pixel rectangular array may be distributed on four sides of the 2x2 optical sensing pixel rectangular array.

In some embodiments of the present application, a center position of a photosensitive area of each of the plurality of photo-sensing pixels is offset from a center position of the same photo-sensing pixel by a first distance, and each of the plurality of photo-sensing pixels is a rectangular pixel, and the first distance is less than or equal to a side length P of the rectangular pixel. For example, the first distance is in the range of P/10 to P/2.

In some embodiments of the application, the oblique light signal in each of the plurality of directions has an angle in the range of 10 degrees to 60 degrees relative to the display screen. For example, the oblique light signals in the multiple directions have the same included angle relative to the display screen.

In other words, the range of oblique incidence angles in air may be 10 degrees to 60 degrees.

In some embodiments of the present application, the at least one light blocking layer is a plurality of light blocking layers, and a bottom light blocking layer of the plurality of light blocking layers is provided with a plurality of openings respectively corresponding to the plurality of optical sensing pixels, so that the one microlens respectively converges oblique light signals in the plurality of directions to the photosensitive regions of the plurality of optical sensing pixels through the plurality of openings. The top light blocking layer of the plurality of light blocking layers is provided with at least one opening corresponding to the plurality of optical sensing pixels. For example, one opening may be provided in the top light blocking layer for each of the plurality of photo-sensing pixels, and for example, one opening may be provided in the top light blocking layer for at least two of the plurality of photo-sensing pixels.

For example, the openings corresponding to the same optical sensing pixel in the plurality of light blocking layers sequentially decrease from top to bottom.

In other words, the aperture in the upper light-blocking layer is set larger than the aperture in the lower light-blocking layer, thereby. The plurality of light blocking layers may be made to direct more (a range of angles) of the light signal to the corresponding photosensitive pixel.

For another example, the metal wiring layers of the plurality of optical sensing pixels are disposed at the rear focal plane position of the one microlens, and the metal wiring layers are respectively formed with a plurality of openings above the photosensitive areas of the plurality of optical sensing pixels to form the bottom light blocking layers of the plurality of light blocking layers.

In other words, the underlying light blocking layer of the plurality of light blocking layers is formed by forming an opening corresponding to the photosensitive region of each of the optical sensing pixels on the metal wiring layer of the fingerprint sensor chip. Alternatively, the metal wiring layer of the fingerprint sensor chip may be multiplexed to the optical path layer between the microlens and the optical sensing pixel.

Taking the at least one light blocking layer as a 2-3 layer diaphragm as an example, four optical sensing pixels (such as photodiode pixels) are arranged below one micro lens, and the center of a light sensing area (ACTIVE AREA, AA) of each optical sensing pixel is offset to the center position of the same optical sensing pixel by reasonable collocation of the diaphragms, so that the micro lens unit can simultaneously receive four optical signals in the oblique directions and respectively converge to the four optical sensing pixels.

In another embodiment of the present application, the at least one light blocking layer is one light blocking layer, and the one light blocking layer is provided with a plurality of inclined holes corresponding to the plurality of optical sensing pixels, respectively, so that the one microlens converges the inclined light signals in the plurality of directions to the photosensitive areas of the plurality of optical sensing pixels through the plurality of inclined holes, respectively.

For example, the thickness of the one light blocking layer is greater than or equal to a preset thickness, so that the plurality of inclined holes are respectively used for transmitting the inclined optical signals in the plurality of directions, and crosstalk of the inclined optical signals transmitted by the plurality of inclined holes can be avoided.

It should be understood that, in a specific implementation, a person skilled in the art may determine the inclination angle of each of the plurality of inclination holes according to the optical path design requirement, where the plurality of inclination holes may be a plurality of inclination holes with different inclination angles, or may be inclination holes with partially or completely identical inclination angles. The direction of the plurality of inclined holes may be a direction in which the optical sensing pixel is expected to receive the optical signal after converging through the micro lens.

In a specific implementation, each of the at least one light blocking layer has a transmittance of less than a preset threshold (e.g., 20%) for light of a specific wavelength band (e.g., visible light or a wavelength band of 610nm or more) to avoid the corresponding light from passing through. The openings may be cylindrical through holes or may be through holes of other shapes, such as polygonal through holes. The aperture may have a pore diameter greater than a predetermined value, for example, greater than 100nm, to facilitate transmission of the desired light for imaging. The aperture of the opening is also smaller than a predetermined value to ensure that the light blocking layer can block unwanted light. For another example, the aperture of the opening may be smaller than the diameter of the microlens.

As an example, the openings in the at least one light blocking layer may also include large-aperture openings that are equivalently synthesized by a plurality of small-aperture openings. For example, the plurality of small-aperture openings may be a plurality of openings corresponding to the plurality of photo-sensing pixels, respectively. For example, a plurality of small-aperture openings for transmitting the optical signals converged by the same microlens in the top light blocking layer of the at least one light blocking layer may be combined into one large-aperture opening.

For example, each of the at least one light blocking layer may be a metal layer, and accordingly, the openings provided in the light blocking layer may be through holes formed in the metal layer. The light blocking layer in the at least one light blocking layer may also be a black high molecular light absorbing material. For example, the at least one light blocking layer has a visible light band transmittance of less than 2% for light signals greater than a preset angle.

It will be appreciated that the aperture parameters should be set as such that as much as possible the light signal required for imaging is maximally transmitted to the photo-sensing pixels, while unwanted light is maximally blocked. For example, the parameters of the apertures may be set to maximize transmission of light signals incident at a particular angle (e.g., 35 degrees) oblique to the corresponding photo-sensing pixels, while maximizing blocking of other light signals.

It is to be understood that the above-described drawings are merely illustrative of the present application and are not to be construed as limiting the present application.

As an example, in some embodiments of the application, the fingerprint detection device may further comprise a transparent medium layer. The transparent medium layer is used for connecting the micro lens, the at least one light blocking layer and the plurality of optical sensing pixels.

For example, the transparent dielectric layer may transmit an optical signal of a target wavelength band (i.e., an optical signal of a wavelength band required for fingerprint detection). For example, the transparent dielectric layer may be oxide or nitride. Optionally, the transparent dielectric layer may include multiple layers to perform protection, transition, and buffering functions, respectively. For example, a transition layer may be provided between the inorganic layer and the organic layer to achieve a tight connection; a protective layer may be provided over the layer susceptible to oxidation to achieve protection.

As another example, in some embodiments of the application, the fingerprint detection device further comprises a filter layer. The filtering layer is arranged in a light path between the micro lens array and the optical sensing pixel array or above the micro lens array, and is used for filtering out optical signals of non-target wave bands so as to transmit the optical signals of the target wave bands.

For example, the filter layer may be a polarizer, a color filter, an infrared filter, etc. to perform functions such as selecting polarization, selecting a specific spectrum.

For another example, the transmittance of the filter layer for light of the target band may be greater than or equal to a preset threshold value, and the cutoff rate for light of the non-target band may be greater than or equal to the preset threshold value. For example, the preset threshold may be 80%. Alternatively, the filter layer may be a separately formed filter layer. For example, the filter layer may be a filter layer formed using blue crystal or blue glass as a carrier. Alternatively, the filter layer may be a plating film formed on the surface of any one of the optical paths. For example, a filter layer may be formed by forming a plating film on the surface of the optical sensor pixel, the surface of any one of the transparent dielectric layers, or the surface of the microlens.

For another example, the fingerprint detection device may further include an image sensor driving unit, a microprogrammed control unit (Microprogrammed Control Unit, MCU), and the like.

The preferred embodiments of the present application have been described in detail above with reference to the accompanying drawings, but the present application is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present application within the scope of the technical concept of the present application, and all the simple modifications belong to the protection scope of the present application.

For example, the specific features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.

As another example, any combination of the various embodiments of the present application may be made without departing from the spirit of the present application, which should also be regarded as the disclosure of the present application.

It should be understood that, in the various method embodiments of the present application, the sequence number of each process described above does not mean that the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

The embodiment of the application also provides electronic equipment which can comprise a display screen and the fingerprint detection device in the embodiment of the application, wherein the fingerprint detection device is arranged below the display screen so as to realize the optical fingerprint detection under the screen.

The electronic device may be any electronic device having a display screen. For example, the electronic device may be the electronic device 10 shown in fig. 1-4.

The display screen may be a display screen in the above description, for example, an OLED display screen or other display screens, and the description of the display screen may refer to the description of the display screen in the above description, which is not repeated herein for brevity.

In some embodiments of the present application, a foam layer may be disposed below the display screen, and the foam layer may be disposed with at least one opening above the fingerprint detection device, the at least one opening being configured to transmit an optical signal reflected by a finger to the fingerprint detection device.

For example, a layer of black foam is arranged below the display screen, an opening can be formed above the fingerprint detection device, when a finger is placed above the lighted display screen, the finger reflects light emitted by the display screen, and the reflected light reflected by the finger penetrates through the display screen and is transmitted to the fingerprint detection device through the at least one opening. A fingerprint is a diffuse reflector whose reflected light exists in all directions.

At this time, a specific light path in the fingerprint detection device may be used, so that the optical sensing pixel array in the fingerprint detection device receives oblique light signals in multiple directions, and a processing unit in the fingerprint detection device or a processing unit connected with the fingerprint detection device may acquire a reconstructed fingerprint image through an algorithm, so as to perform fingerprint identification.

In some embodiments of the application, a gap may or may not exist between the fingerprint detection device and the display screen.

For example, a gap of 0-1000um may exist between the fingerprint detection device and the display screen.

In some embodiments of the present application, the fingerprint detection device may output the acquired image to MCU, FPGA, DSP, a computer-specific processor, or a specific processor of an electronic device, so as to perform fingerprint recognition.

It should be understood that the specific examples of the embodiments of the present application are intended to facilitate a better understanding of the embodiments of the present application by those skilled in the art, and are not intended to limit the scope of the embodiments of the present application.

It is to be understood that the terminology used in the embodiments of the application and in the appended claims is for the purpose of describing particular embodiments only, and is not intended to be limiting of the embodiments of the application. For example, as used in the embodiments of the application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Those of ordinary skill in the art will appreciate that the elements of the examples described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the elements and steps of the examples have been described above generally in terms of functionality for clarity of understanding of interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the several embodiments provided in the present application, it should be understood that the disclosed system and apparatus may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. In addition, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices, or elements, or may be an electrical, mechanical, or other form of connection.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiment of the present application.

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

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application is essentially or a part contributing to the prior art, or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a usb disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

While the application has been described with reference to certain preferred embodiments, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made and equivalents will be apparent to those skilled in the art without departing from the scope of the application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims

1. The utility model provides a fingerprint detection device, its characterized in that is applicable to the below of display screen in order to realize the optical fingerprint detection under the screen, fingerprint detection device is including being array distribution or crisscross a plurality of fingerprint detection units that set up, every fingerprint detection unit in a plurality of fingerprint detection units includes:

a plurality of optical sensing pixels, the optical sensing pixels being photosensors;

At least one microlens disposed over the plurality of photo-sensing pixels;

The optical sensing device comprises at least one micro lens, wherein oblique optical signals in 2M directions reflected by a finger above the display screen are respectively transmitted to the plurality of optical sensing pixels through openings arranged in the at least one light blocking layer after being converged by the at least one micro lens, the oblique optical signals are used for detecting fingerprint information of the finger, M is a positive integer, the 2M directions comprise a first direction and a second direction, and projection of the first direction on the display screen is perpendicular to projection of the second direction on the display screen.

2. The fingerprint detection device according to claim 1, wherein a projection of said first direction or said second direction onto said display screen is perpendicular to a polarization direction of said display screen.

3. The fingerprint detection device according to claim 1 wherein said plurality of photo sensing pixels form a rectangular array of photo sensing pixels, a projection of said first direction or said second direction onto said rectangular array of photo sensing pixels being parallel to a diagonal direction of said rectangular array of photo sensing pixels.

4. A fingerprint sensing device according to any one of claims 1 to 3 wherein said at least one microlens is one microlens, said plurality of photo sensing pixels being a first column of photo sensing pixels in a 2x2 matrix array of photo sensing pixels, said one microlens being located above a central location of said 2x2 matrix array of photo sensing pixels, a second column of photo sensing pixels of said 2x2 matrix array of photo sensing pixels being multiplexed to photo sensing pixels in a first column of photo sensing pixels in other fingerprint sensing units.

5. The fingerprint detection device according to claim 4 wherein two fingerprint detection units of said fingerprint detection device that are adjacent in a row direction of said 2x2 matrix array of photo-sensing pixels are offset by one photo-sensing pixel in an arrangement direction of a first column of photo-sensing pixels of said 2x2 matrix array of photo-sensing pixels.

6. A fingerprint detection device according to any one of claims 1 to 3 wherein said at least one microlens is one microlens, said plurality of photo sensing pixels being a first row first column photo sensing pixel and a fourth row first column photo sensing pixel of a first column photo sensing pixel in a 4x2 matrix array of photo sensing pixels, said one microlens being located above a center position of a side of a second column photo sensing pixel in said 4x2 matrix array remote from said first column photo sensing pixel, said 4x2 matrix array of photo sensing pixels other than said first row first column photo sensing pixel and said fourth row first column photo sensing pixel being multiplexed into photo sensing pixels in other fingerprint detection units.

7. The fingerprint detection device according to claim 6 wherein two fingerprint detection units in said fingerprint detection device that are adjacent in a row direction of said 4x2 matrix array of photo-sensing pixels are offset by one photo-sensing pixel in an arrangement direction of a first column of photo-sensing pixels in said 4x2 matrix array of photo-sensing pixels.

8. A fingerprint sensing device according to any one of claims 1 to 3 wherein said plurality of photo sensing pixels is a rectangular array of 4x4 photo sensing pixels, said rectangular array of 4x4 photo sensing pixels comprising 4 rectangular arrays of 2x2 photo sensing pixels distributed in an array, wherein a first column, first row, 2x2, photo sensing pixel rectangular array and a second row, 2x2, photo sensing pixel rectangular array of said rectangular array of 4x4 photo sensing pixels are arranged to receive oblique light signals in one direction, and wherein a first column, second row, 2x2, photo sensing pixel rectangular array of said rectangular array of 4x4 photo sensing pixels and a first row, second column, 2x2 photo sensing pixel rectangular array are arranged to receive oblique light signals in another direction.

9. The fingerprint detection device according to claim 8 wherein said at least one microlens comprises a rectangular array of 3x2 microlenses and two rectangular arrays of 2x2 microlenses, said rectangular array of 3x2 microlenses being located above a first column to a third column of said rectangular array of 4x4 photo-sensing pixels, said rectangular arrays of 2x2 microlenses being located above a first and a fourth row of said rectangular array of 4x4 photo-sensing pixels, respectively, four microlenses of each rectangular array of 2x2 microlenses being located above four corners of the corresponding rectangular array of photo-sensing pixels, such that a first row of 2x2 photo-sensing pixels and a second row of 2x2 photo-sensing pixels of said rectangular array of 4x4 photo-sensing pixels receive a diagonal of said rectangular array of 4x4 photo-sensing pixels and a diagonal of said rectangular array of 4x 2 photo-sensing pixels and said diagonal of second row of 2x2 photo-sensing pixels.

10. The fingerprint detection device according to claim 9 wherein the microlenses of said two 2x2 rectangular arrays of microlenses located above the sides of said 4x4 rectangular array of optically sensitive pixels are multiplexed into microlenses of other fingerprint detection units.

11. The fingerprint detection device according to claim 8 wherein each of said rectangular arrays of 4x4 photo-sensing pixels is configured to receive light signals converged by a microlens above adjacent photo-sensing pixels such that a first column of said rectangular array of 4x4 photo-sensing pixels has a first row of 2x2 photo-sensing pixels and a second row of 2x2 photo-sensing pixels receives oblique light signals in a direction in which one side of said rectangular array of 4x4 photo-sensing pixels is located, and a first column of said rectangular array of 4x4 photo-sensing pixels has a second row of 2x2 photo-sensing pixels and a first row of 2x2 photo-sensing pixels receives oblique light signals in a direction in which another side of said rectangular array of 4x4 photo-sensing pixels is located adjacent to said one side.

12. The fingerprint detection device according to claim 11 wherein the microlenses of said at least one microlens located above the outer region of said rectangular array of 4x4 optically sensitive pixels are multiplexed into microlenses in other fingerprint detection units.

13. A fingerprint detection device according to any one of claims 1 to 3 wherein said plurality of photo-sensing pixels are a plurality of rows of photo-sensing pixels, at least one first row of photo-sensing pixels of said plurality of rows being arranged to receive oblique light signals in one direction and at least one second row of photo-sensing pixels of said plurality of rows being arranged to receive oblique light signals in another direction.

14. The fingerprint detection device according to claim 13 wherein each of said plurality of rows of photo-sensing pixels is configured to receive light signals converging from a microlens above an adjacent photo-sensing pixel such that said at least one row of first photo-sensing pixels receives oblique light signals along a direction of arrangement of photo-sensing pixels and said at least one row of second photo-sensing pixels receives oblique light signals along a direction perpendicular to the direction of arrangement of photo-sensing pixels.

15. The fingerprint detection device according to claim 13 wherein said at least one microlens is a 3x1 rectangular array of microlenses, said plurality of optically sensitive pixels being a first column of optically sensitive pixels in a rectangular array of 4x2 optically sensitive pixels, said rectangular array of 3x1 microlenses being located above said rectangular array of 4x2 optically sensitive pixels, a second column of optically sensitive pixels in said rectangular array of 4x2 optically sensitive pixels being multiplexed to optically sensitive pixels in other fingerprint detection units.

16. The fingerprint detection device according to any one of claims 1 to 3 wherein said at least one light blocking layer is a multilayer light blocking layer, a bottom light blocking layer of said multilayer light blocking layer being provided with a plurality of apertures corresponding to said plurality of photo-sensing pixels, respectively, such that said at least one microlens converges oblique light signals in said 2M directions to said plurality of photo-sensing pixels, respectively, through said plurality of apertures.

17. The fingerprint detection device according to claim 16 wherein the openings in the plurality of light blocking layers corresponding to the same optically sensitive pixel decrease in order from top to bottom.

18. The fingerprint detection device according to claim 16 wherein a top light blocking layer of the multi-layer light blocking layer is provided with at least one aperture corresponding to the plurality of optically sensitive pixels.

19. A fingerprint detection device according to any one of claims 1 to 3 wherein said at least one light blocking layer is a layer of light blocking layer provided with a plurality of inclined holes corresponding to said plurality of optically sensitive pixels, respectively, such that said at least one microlens focuses said 2M-direction inclined light signals to said plurality of optically sensitive pixels, respectively, through a plurality of apertures.

20. The fingerprint detection device according to claim 19, wherein the thickness of the one light blocking layer is greater than or equal to a preset thickness such that the plurality of inclined holes are respectively used for transmitting inclined light signals in the 2M directions.

21. A fingerprint sensing device according to any one of claims 1-3, further comprising a transparent dielectric layer for connecting said at least one microlens, said at least one light blocking layer and said plurality of optically sensitive pixels.

22. A fingerprint sensing device according to any one of claims 1 to 3, further comprising a filter layer arranged in the optical path between said at least one microlens and said plurality of optically sensitive pixels or above said microlens for filtering out optical signals of non-target wavelength bands for transmission of optical signals of target wavelength bands.

23. An electronic device, comprising:

a display screen; and

The fingerprint detection device according to any one of claims 1-22, said device being arranged below said display screen for enabling off-screen optical fingerprint detection.