CN111881873A

CN111881873A - Fingerprint identification device and electronic equipment

Info

Publication number: CN111881873A
Application number: CN202010774172.XA
Authority: CN
Inventors: 蒋鹏
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2020-08-04
Filing date: 2020-08-04
Publication date: 2020-11-03
Anticipated expiration: 2040-08-04

Abstract

A fingerprint identification device and an electronic apparatus are provided, which can improve the performance of the fingerprint identification device and reduce the cost thereof. The fingerprint identification device includes: fingerprint identification module includes: a microlens; the light guide device comprises at least two diaphragm layers, wherein each diaphragm layer of the at least two diaphragm layers is provided with a light through hole to form a plurality of light guide channels in different directions; the pixel units are arranged below the at least two layers of diaphragm layers and positioned at the bottoms of the light guide channels; after fingerprint optical signals returned after being reflected or scattered by a finger above the display screen are converged by the micro lens, a plurality of target fingerprint optical signals in different directions are respectively transmitted to the plurality of pixel units through the plurality of light guide channels, and the plurality of target fingerprint optical signals are used for detecting fingerprint information of the finger.

Description

Fingerprint identification device and electronic equipment

Technical Field

The present application relates to the field of optical fingerprint technology, and more particularly, to a fingerprint identification device and an electronic apparatus.

Background

With the rapid development of the mobile phone industry, the application of the optical fingerprint technical scheme under the screen is more and more popular, and terminal manufacturers have strong demands for the scheme with thinner thickness, lower performance and lower cost.

In some related technologies, the microlens array in the fingerprint identification device is located right above the pixel array, and one microlens corresponds to one pixel unit, that is, each microlens in the microlens array focuses received light to a pixel unit corresponding to the same microlens, and a plurality of pixel units are arranged in an array. By adopting the technical scheme, the whole light inlet quantity of the fingerprint identification device is small, the exposure time is long, the whole imaging quality is poor, and the identification performance of the dry finger is not good. Meanwhile, the thickness of the light path in the fingerprint identification device is thick, the processing difficulty and cost of the light path are increased, and the development of the light and thin fingerprint identification device is not facilitated.

Therefore, how to comprehensively improve the performance of the fingerprint identification device and reduce the cost thereof is an urgent problem to be solved.

Disclosure of Invention

The embodiment of the application provides a fingerprint identification device and electronic equipment, which can reduce the cost of the fingerprint identification device while improving the performance of the fingerprint identification device.

In a first aspect, a fingerprint identification device is provided, which is suitable for the below of a display screen to realize optical fingerprint identification under the screen, and comprises: fingerprint identification module, including a plurality of fingerprint identification units, every fingerprint identification unit in these a plurality of fingerprint identification units includes: a microlens; at least two layers of diaphragm layers, which are arranged below the micro lens, wherein each light filtering layer of the at least two layers of diaphragm layers is provided with a light through hole to form a plurality of light guide channels in different directions, in the at least two layers of diaphragm layers, the non-light through hole area of at least one layer of first diaphragm layer is used for absorbing visible light, and the non-light through hole area of at least one layer of second diaphragm layer is used for transmitting non-pixel sensitive light and absorbing pixel sensitive light; the pixel units are arranged below the at least two layers of diaphragm layers, the responsivity of the pixel units to the non-pixel sensitive light is less than or equal to a first preset threshold, the responsivity of the pixel units to the non-pixel sensitive light is greater than or equal to a second preset threshold, the first preset threshold is less than the second preset threshold, and the pixel units are respectively positioned at the bottoms of the light guide channels; the fingerprint light signals returned after being reflected or scattered by the finger above the display screen are converged by the micro lens, wherein a plurality of target fingerprint light signals in different directions are respectively transmitted to the plurality of pixel units through the plurality of light guide channels, and the plurality of target fingerprint light signals are used for detecting the fingerprint information of the finger.

Through the technical scheme of this application, a microlens corresponds a plurality of pixel units, and a plurality of pixel units receive respectively through this microlens convergence and through the fingerprint optical signal of a plurality of directions of a plurality of light-directing channel, and the fingerprint optical signal of this a plurality of directions is received by a plurality of pixel units respectively. Compared with the technical scheme that one microlens corresponds to one pixel unit, the light-entering amount of the fingerprint identification device can be increased, the exposure time is shortened, and the view field of the fingerprint identification device is increased.

In addition, the angles of the fingerprint optical signals received by the pixel units are determined by the relative position relationship between the pixel units and the micro lens, and the pixel units can receive the fingerprint optical signals with large angles by flexibly setting the positions of the pixel units, so that the identification problem of dry fingers is further improved, the thickness of a light path in the fingerprint identification unit can be further reduced, the thickness of the fingerprint identification device is reduced, and the process cost is reduced.

In addition, the cost of the diaphragm layer in this scheme than traditional blackfilled compound material is lower, and the machining precision is high, can improve the uniformity and the production yield of product, in addition, because the size and the position of the logical unthreaded hole in this diaphragm layer all can accurate control, can improve the control accuracy to light guide channel, thereby improve the image quality, meanwhile, the stray light of pixel unit top can also be absorbed to the bottommost diaphragm layer in this scheme, further improve the image quality, thereby promote fingerprint identification device's wholeness ability.

In conclusion, by the above scheme, the overall light incoming amount of the fingerprint identification device is improved, the identification problem of dry fingers is improved, the thickness of a light path is reduced, the performance of the fingerprint identification device is comprehensively improved, and meanwhile, the manufacturing process precision and yield of the fingerprint identification device are improved, and the process cost is reduced, so that the fingerprint identification device in the embodiment of the application has a wider application scene at low cost and is beneficial to the light and thin development of the electronic equipment where the fingerprint identification device is located.

In one possible embodiment, the non-light-transmitting hole region of the first diaphragm layer is also used for transmitting infrared light, and the non-light-transmitting hole region of the first diaphragm layer is a visible light cut-off filter layer for transmitting infrared light.

In a possible implementation, the fingerprint identification device further includes: and the infrared cut-off filter is arranged in a light path from the display screen to the plurality of pixel units in the fingerprint identification module.

In one possible embodiment, the infrared cut filter is disposed above the fingerprint identification module.

In this embodiment, set up infrared cut-off filter in fingerprint identification module top, can prevent that the reflection of light signal between the metal level of light filter and a plurality of pixel cell place chips from forming stray light, meanwhile, can also avoid the ambient interference light to get into the pixel cell, in other words, adopt the structure of this application embodiment, can reduce stray light and ambient interference light, improve the quality of fingerprint image, further improve fingerprint identification device's wholeness ability.

In one possible embodiment, the non-pixel sensitive light is a first color light, the pixel sensitive light includes a second color light, and the non-light-passing hole area in the second aperture layer is used for transmitting the first color light and absorbing the second color light.

In one possible embodiment, the first color light is blue light, and the non-through aperture region of the second stop layer is a filter layer formed by a blue filter material or a filter layer formed by a violet filter material.

In a possible implementation manner, the display screen is configured to emit the second color light in the finger pressing area, and the second color fingerprint light returned after being reflected or scattered from the finger is converged by the microlens, wherein a plurality of second color target fingerprint light signals in different directions are respectively transmitted to the plurality of pixel units through the plurality of light guide channels, and the plurality of second color target fingerprint light signals are used for detecting fingerprint information of the finger.

In one possible embodiment, the second color light is green or cyan.

In a possible embodiment, the first predetermined threshold is equal to or less than 10%, and the second predetermined threshold is equal to or greater than 70%.

In a possible embodiment, the absorbance of the non-clear aperture area of the at least one second diaphragm layer sensitive to the pixel is greater than a third preset threshold.

In a possible embodiment, the third preset threshold is equal to or greater than 70%.

In a possible embodiment, the at least two diaphragm layers are three diaphragm layers, a middle diaphragm layer of the three diaphragm layers is the first diaphragm layer, and a top diaphragm layer and a bottom diaphragm layer of the three diaphragm layers are the second diaphragm layer.

In a possible implementation manner, a plurality of light-passing holes corresponding to the plurality of pixel units in a one-to-one manner are arranged in the middle diaphragm layer of the three diaphragm layers to form the plurality of light-guiding channels.

In a possible implementation manner, one light-passing hole is disposed in a top diaphragm layer of the three diaphragm layers, and a plurality of light-passing holes corresponding to the plurality of pixel units one to one are disposed in a bottom diaphragm layer of the three diaphragm layers, so as to form the plurality of light-guiding channels.

In one possible embodiment, the plurality of pixel units are formed in a sensor chip, the height of an optical path between the lower surface of the micro lens and the upper surface of the sensor chip is H,

the distance between the bottom diaphragm layer of the three diaphragm layers and the upper surface of the sensor chip is between 0 and H/3, the distance between the middle diaphragm layer of the three diaphragm layers and the upper surface of the sensor chip is between H/5 and 2H/3, and the distance between the top diaphragm layer of the at least two diaphragm layers and the upper surface of the sensor chip is between H/2 and H.

In a possible embodiment, the at least two diaphragm layers are two diaphragm layers, a bottom diaphragm layer of the two diaphragm layers is the first diaphragm layer, and a top diaphragm layer of the two diaphragm layers is the second diaphragm layer.

In a possible implementation manner, a bottom diaphragm layer of the two diaphragm layers is provided with a plurality of light through holes corresponding to the plurality of pixel units one by one, respectively, so as to form the plurality of light guide channels.

In a possible embodiment, a light-passing hole is provided in the top diaphragm layer of the two diaphragm layers to form the plurality of light-guiding channels.

the distance between the bottom diaphragm layer of the at least two diaphragm layers and the upper surface of the sensor chip is between H/5 and 2H/3, and the distance between the top diaphragm layer of the at least two diaphragm layers and the upper surface of the sensor chip is between H/2 and H.

In a possible embodiment, the aperture of the light-passing holes in the plurality of light-guiding channels decreases from top to bottom.

In one possible embodiment, the plurality of pixel units are formed in a sensor chip, the diameter of the micro lens is D, the optical path height between the lower surface of the micro lens and the upper surface of the sensor chip is H, the optical path height between one of the at least two diaphragm layers and the upper surface of the sensor chip is H, and the aperture diameter D of the light through hole in the one diaphragm layer is in the range of (1 ± 0.3) × D × H/H.

In a possible implementation, the fingerprint identification device further includes: the metal circuit layer is provided with a plurality of light through holes, the light through holes are correspondingly arranged above the pixel units one by one, and the light through holes are correspondingly arranged below the light guide channels one by one;

the plurality of target fingerprint optical signals are conducted to the plurality of light through holes in the metal circuit layer through the plurality of light guide channels and conducted to the plurality of pixel units through the plurality of light through holes.

In a possible embodiment, the center of the light through hole in a first light guide channel of the plurality of light guide channels is located on a first straight line, and the light through hole in the metal circuit layer corresponding to the first light guide channel is also located on the first straight line.

In a possible embodiment, the light holes in the at least two diaphragm layers and the light holes in the metal circuit layer are circular light holes.

In a possible embodiment, the diameter of the light through hole in the metal circuit layer is smaller than the diameter of the light through hole in the bottom diaphragm layer in the at least two diaphragm layers.

In a possible embodiment, each fingerprint recognition unit further comprises: and the transparent medium layer is used for connecting the at least two diaphragm layers.

In a possible embodiment, each fingerprint recognition unit further comprises: the first buffer layer is used for connecting the micro lens with the top diaphragm layer of the at least two diaphragm layers; and the second buffer layer is used for connecting the sensor chip with the bottom diaphragm layer in the at least two diaphragm layers.

In one possible embodiment, the difference between the refractive indexes of the transparent medium layer and the first buffer layer and the difference between the refractive indexes of the transparent medium layer and the second buffer layer are within a predetermined threshold.

In one possible embodiment, the plurality of pixel units are four pixel units, the four pixel units form a pixel area of a quadrilateral area, and the center point of the pixel area is coincident with or not coincident with the center of the microlens in the vertical direction.

In a possible embodiment, the plurality of light guide channels are four light guide channels, and at least three of the four light guide channels are inclined with respect to the display screen.

Adopt the scheme of this application embodiment, through the direction that sets up light guide channel, can be so that the fingerprint light signal of incline direction is received respectively to the pixel in four pixel, and the fingerprint light signal of incline direction can improve the fingerprint identification problem of doing the finger, and can reduce fingerprint identification device's thickness.

In one possible embodiment, the four light-guiding channels are angled between 10 and 45 ° with respect to the direction perpendicular to the display screen.

The light signal intensity and the gradient of light guide channel are comprehensively considered, the scheme of the embodiment of the application can satisfy the intensity of the light signal and control the thickness of the light path of the whole fingerprint identification device while improving the problem of dry finger identification.

In one possible embodiment, each of the four pixel units includes four photosensitive regions, and the four photosensitive regions are respectively located at the bottoms of the four light guide channels.

In one possible embodiment, at least one of the four photosensitive regions is disposed off-center from the pixel cell in which it is located.

In one possible embodiment, the at least one photosensitive area is offset in a direction away from the center of the microlens.

In one possible implementation, the four pixel units form a quadrilateral pixel area, and the four photosensitive areas are respectively located at four corners of the pixel area.

In one possible implementation, the fingerprint identification module includes a plurality of groups of the four pixel units; the optical signals received by a plurality of first pixel units in a plurality of groups of the four pixel units are used for forming a first fingerprint image of the finger, the optical signals received by a plurality of second pixel units in the plurality of groups of the four pixel units are used for forming a second fingerprint image of the finger, the optical signals received by a plurality of third pixel units in the plurality of groups of the four pixel units are used for forming a third fingerprint image of the finger, the optical signals received by a plurality of fourth pixel units in the plurality of groups of the four pixel units are used for forming a fourth fingerprint image of the finger, and one or more images of the first fingerprint image, the second fingerprint image, the third fingerprint image and the fourth fingerprint image are used for fingerprint identification.

In one possible embodiment, every X in the plurality of first pixel units₁×X₂The first pixel units are connected to the first summation and average circuitPhysical pixel synthesis, forming a pixel value in the first intermediate fingerprint image; every X in the plurality of second pixel units₁×X₂The second pixel units are connected to the second summing and averaging circuit to perform physical pixel synthesis to form a pixel value in the second intermediate fingerprint image; every X in the plurality of third pixel units₁×X₂The third pixel units are connected to the third summing and averaging circuit to perform physical pixel synthesis to form a pixel value in the third intermediate fingerprint image; every X in the plurality of fourth pixel units₁×X₂The fourth pixel units are connected to the fourth summing and averaging circuit to perform physical pixel synthesis to form a pixel value in the fourth intermediate fingerprint image; wherein, X₁And X₂Is a positive integer.

In a possible implementation, the fingerprint identification device further includes: the first sum-average circuit, the second sum-average circuit, the third sum-average circuit, and the fourth sum-average circuit.

In a possible embodiment, every Y in the first intermediate fingerprint image₁×Y₂The pixel values are used for carrying out digital pixel synthesis to form a pixel value in the first fingerprint image; every Y in the second intermediate fingerprint image₁×Y₂The pixel value is used for carrying out digital pixel synthesis to form a pixel value in the second fingerprint image; every Y in the third intermediate fingerprint image₁×Y₂The pixel values are used for carrying out digital pixel synthesis to form a pixel value in the third fingerprint image; every Y in the fourth intermediate fingerprint image₁×Y₂The pixel values are used for carrying out digital pixel synthesis to form a pixel value in the fourth fingerprint image; wherein, Y₁And Y₂Is a positive integer.

In a possible implementation, the fingerprint identification device further includes: a processing unit for performing digital pixel synthesis on the first intermediate fingerprint image, the second intermediate fingerprint image, the third intermediate fingerprint image and the fourth intermediate fingerprint image.

By adopting the scheme of the embodiment, the number of pixels in the fingerprint image processing process can be reduced, the fingerprint identification speed is improved, and in the embodiment, if a plurality of pixel units have faults, the plurality of pixel units can still obtain pixel values through pixel synthesis output, so that the formation of the fingerprint image and the fingerprint identification effect cannot be influenced.

In a possible embodiment, the first intermediate fingerprint image, the second intermediate fingerprint image, the third intermediate fingerprint image and the fourth intermediate fingerprint image are used for digital pixel synthesis after being low-pass filtered.

In a possible implementation, the fingerprint identification device further includes: a low pass filter for low pass filtering the first intermediate fingerprint image, the second intermediate fingerprint image, the third intermediate fingerprint image and the fourth intermediate fingerprint image.

By adopting the scheme of the embodiment, the influence of the moire fringes in the fingerprint image can be reduced.

In one possible embodiment, X₁＝X₂＝Y₁＝Y₂＝2。

In one possible embodiment, the first pixel units are not adjacent to each other, the second pixel units are not adjacent to each other, the third pixel units are not adjacent to each other, and the fourth pixel units are not adjacent to each other.

In one possible implementation mode, the arrangement period of the luminous pixels in the display screen is P₁Spatial sampling period P of the fingerprint recognition device₂＜P₁/2。

Adopt the scheme of this embodiment, can be so that fingerprint identification device's the space imaging cycle of the relative display screen of space sampling cycle satisfies the nyquist sampling law, promptly, can avoid appearing moire fringe in the fingerprint image, corresponding, promote the fingerprint identification effect.

In a possible implementation manner, the spatial sampling period of the fingerprint identification device is calculated according to the arrangement period of the plurality of fingerprint identification units and the pixel synthesis manner.

In one possible embodiment, the arrangement period of the plurality of fingerprint identification units is between 12 μm and 20 μm.

In one possible embodiment, the optical path thickness of each fingerprint identification unit of the plurality of fingerprint identification units is within 30 μm.

In one possible embodiment, the distance between the fingerprint recognition device and the display screen is 0 to 1 mm.

In a second aspect, an electronic device is provided, comprising: a display screen; and the fingerprint identification device in the first aspect or any one of the possible embodiments of the first aspect, the fingerprint identification device being disposed below the display screen to implement the optical fingerprint identification under the screen.

In a possible embodiment, the display screen is used for displaying green, cyan or white light spots in the fingerprint detection area, and the fingerprint identification device is used for receiving green, cyan or white target fingerprint light signals to detect fingerprint information of a finger.

Set up above-mentioned fingerprint identification device in electronic equipment, through promoting fingerprint identification device's fingerprint identification performance and reduce fingerprint identification device's cost to promote this electronic equipment's fingerprint identification performance and reduce electronic equipment's cost.

Drawings

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

Fig. 2 is a schematic cross-sectional view of a fingerprint identification device provided in an embodiment of the present application.

Fig. 3 is a schematic cross-sectional view of another fingerprint identification device provided by the embodiment of the present application.

Fig. 4 is a schematic top view of the fingerprint recognition device of fig. 3.

Fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Fig. 6 is a schematic diagram of relevant structural parameters of three layers of diaphragm layers in a fingerprint identification unit according to an embodiment of the application.

Fig. 7 is a schematic top view of a fingerprint identification unit of fig. 3.

Fig. 8 is another schematic top view of a fingerprint identification unit of fig. 3.

Fig. 9 is a schematic cross-sectional view of another fingerprint identification device provided by an embodiment of the present application.

FIG. 10 is a diagram of a pixel array in a fingerprint recognition device according to an embodiment of the present application.

Fig. 11 is a schematic diagram of an image processing method according to an embodiment of the present application.

Detailed Description

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

It should be understood that the embodiments of the present application can be applied to optical fingerprint systems, including but not limited to optical fingerprint identification systems and products based on optical fingerprint imaging, and the embodiments of the present application are only described by way of example, but not limited to any limitation, and the embodiments of the present application are also applicable to other systems using optical imaging technology, etc.

As a common application scenario, the optical fingerprint system provided by the embodiment of the application can be applied to smart phones, tablet computers and other mobile terminals or other electronic devices with display screens; more specifically, in the above electronic device, the fingerprint recognition device may be embodied as an optical fingerprint device, which may be disposed in a partial area or an entire area below the display screen, thereby forming an Under-screen (Under-display) optical fingerprint system. Alternatively, the fingerprint identification device may be partially or completely integrated into a display screen of the electronic device, so as to form an In-display (In-display) optical fingerprint system.

Fig. 1 is a schematic structural diagram of an electronic device to which the embodiment of the present invention is applicable, where the electronic device 10 includes a display screen 120 and an optical fingerprint device 130, where the optical fingerprint device 130 is disposed in a local area below the display screen 120. The optical fingerprint device 130 comprises an optical fingerprint sensor including a sensing array 133 having a plurality of optical sensing units 131, where the sensing array 133 is located or a sensing area thereof is a fingerprint detection area 103 of the optical fingerprint device 130. As shown in fig. 1, the fingerprint detection area 103 is located in a display area of the display screen 120. In an alternative embodiment, the optical fingerprint device 130 may be disposed at other locations, such as the side of the display screen 120 or the edge opaque region of the electronic device 10, and the optical path is designed to guide the optical signal of at least a portion of the display area of the display screen 120 to the optical fingerprint device 130, such that the fingerprint detection area 103 is actually located in the display area of the display screen 120.

It should be appreciated that the area of fingerprint sensing area 103 may be different from the area of the sensing array of optical fingerprint device 130, for example, the area of fingerprint sensing area 103 of optical fingerprint device 130 may be larger than the area of the sensing array of optical fingerprint device 130 by optical path design such as lens imaging, reflective folded optical path design, or other optical path design where light is converged or reflected. In other alternative implementations, if light path guidance is performed using, for example, light collimation, fingerprint sensing area 103 of optical fingerprint device 130 may also be designed to substantially coincide with the area of the sensing array of optical fingerprint device 130.

Therefore, when the user needs to unlock or otherwise verify the fingerprint of the electronic device, the user only needs to press the finger on the fingerprint detection area 103 of the display screen 120, so as to input the fingerprint. Since fingerprint detection can be implemented in the screen, the electronic device 10 with the above structure does not need to reserve a space on the front surface thereof to set a fingerprint key (such as a Home key), so that a full-screen scheme can be adopted, that is, the display area of the display screen 120 can be substantially extended to the front surface of the whole electronic device 10.

As an alternative implementation, as shown in fig. 1, the optical fingerprint device 130 includes a light detection portion 134 and an optical component 132, where the light detection portion 134 includes a sensing array, and a reading circuit and other auxiliary circuits electrically connected to the sensing array, which can be fabricated on a chip (Die) through a semiconductor process, such as an optical imaging chip or an optical fingerprint sensor, the sensing array is specifically a Photo detector (Photo detector) array, which includes a plurality of Photo detectors distributed in an array, and the Photo detectors can be used as the optical sensing units; the optical assembly 132 may be disposed above the sensing array of the light detection portion 134, and may specifically include a light guiding layer or a light path guiding structure for guiding the reflected light reflected from the surface of the finger to the sensing array for optical detection, and other optical elements.

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

For example, the light guide layer may be a Collimator (collimateror) layer fabricated on a semiconductor silicon wafer, and the collimater unit may be a small hole, and in the reflected light reflected from the finger, the light perpendicularly incident to the collimater unit may pass through and be received by the optical sensing unit below the collimater unit, and the light with an excessively large incident angle is attenuated by multiple reflections inside the collimater unit, so that each optical sensing unit can only receive the reflected light reflected from the fingerprint pattern directly above the optical sensing unit, and the sensing array can detect the fingerprint image of the finger.

In another embodiment, the light guiding layer or the light path guiding structure may also be an optical Lens (Lens) layer, which has one or more Lens units, such as a Lens group composed of one or more aspheric lenses, and is used to focus the reflected light reflected from the finger to the sensing array of the light detecting portion 134 therebelow, so that the sensing array can image based on the reflected light, thereby obtaining the fingerprint image of the finger. Optionally, the optical lens layer may further be formed with a pinhole in the optical path of the lens unit, and the pinhole may cooperate with the optical lens layer to enlarge the field of view of the optical fingerprint device, so as to improve the fingerprint imaging effect of the optical fingerprint device 130.

In other embodiments, the light guide layer or the light path guiding structure may also specifically adopt a Micro-Lens (Micro-Lens) layer, the Micro-Lens layer has a Micro-Lens array formed by a plurality of Micro-lenses, which may be formed above the sensing array of the light detecting portion 134 through a semiconductor growth process or other processes, and each Micro-Lens may correspond to one of the sensing units of the sensing array. And, other optical film layers may be further formed between the microlens layer and the sensing unit, such as a dielectric layer or a passivation layer, and more specifically, a light blocking layer having micro holes may be further included between the microlens layer and the sensing unit, where the micro holes are formed between the corresponding microlenses and the sensing unit, and the light blocking layer may block optical interference between adjacent microlenses and the sensing unit, and enable light rays corresponding to the sensing unit to be converged into the micro holes through the microlenses and transmitted to the sensing unit through the micro holes to perform optical fingerprint imaging. It should be understood that several implementations of the above-described optical path directing structure may be used alone or in combination, for example, a microlens layer may be further disposed 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 lamination structure or optical path thereof may need to be adjusted according to actual needs.

As an alternative embodiment, the display screen 120 may adopt a display screen having a self-Light Emitting display unit, such as an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. Taking the OLED display screen as an example, the optical fingerprint device 130 may use the display unit (i.e., the OLED light source) of the OLED display screen 120 located in the fingerprint detection area 103 as an excitation light source for optical fingerprint detection. When the finger 140 is pressed against the fingerprint detection area 103, the display screen 120 emits a beam of light 111 toward the target finger 140 above the fingerprint detection area 103, and the light 111 is reflected at the surface of the finger 140 to form reflected light or scattered light by scattering through the inside of the finger 140 to form scattered light, which is collectively referred to as reflected light for convenience of description in the related patent application. Because the ridges (ridges) and the valleys (valley) of the fingerprint have different light reflection capacities, the reflected light 151 from the ridge 141 and the reflected light 152 from the valley 142 have different light intensities, and after passing through the optical assembly 132, the reflected light is received by the sensing array 134 in the optical fingerprint device 130 and converted into corresponding electrical signals, i.e., fingerprint detection signals; based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, so that an optical fingerprint identification function is realized in the electronic device 10.

In other embodiments, the optical fingerprint device 130 may also use an internal light source or an external light source to provide the light signal for fingerprint detection. In this case, the optical fingerprint device 130 may be adapted for use with a non-self-emissive display such as a liquid crystal display or other passively emissive display. Taking an application to a liquid crystal display screen with a backlight module and a liquid crystal panel as an example, to support the underscreen fingerprint detection of the liquid crystal display screen, 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 specifically be an infrared light source or a light source of non-visible light with a specific wavelength, and may be disposed below the backlight module of the liquid crystal display screen or in an edge area below a protective cover plate of the electronic device 10, and the optical fingerprint device 130 may be disposed below the edge area of the liquid crystal panel or the protective cover plate and guided through a light path so that the fingerprint detection light may reach the optical fingerprint device 130; alternatively, the optical fingerprint device 130 may be disposed under the backlight module, and the backlight module is configured to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint device 130 by perforating or performing other optical designs on the diffusion sheet, the brightness enhancement sheet, the reflection sheet, and other film layers. When the optical fingerprint device 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 the same as that described above.

It should be understood that in particular implementations, the electronic device 10 also includes a transparent protective cover plate, which may be a glass cover plate or a sapphire cover plate, positioned over the display screen 120 and covering the front face of the electronic device 10. Because, in the embodiment of the present application, the pressing of the finger on the display screen 120 actually means pressing on the cover plate above the display screen 120 or the surface of the protective layer covering the cover plate.

It should also be understood that electronic device 10 may also include a circuit board 150 disposed below optical fingerprint arrangement 130. The optical fingerprint device 130 may be adhered to the circuit board 150 by a back adhesive, and electrically connected to the circuit board 150 by soldering a pad and a wire. Optical fingerprint device 130 may be electrically interconnected and signal-transferred to other peripheral circuits or other components of electronic device 10 via circuit board 150. For example, the optical fingerprint device 130 may receive a control signal of a processing unit of the electronic apparatus 10 through the circuit board 150, and may also output a fingerprint detection signal from the optical fingerprint device 130 to the processing unit or the control unit of the electronic apparatus 10 through the circuit board 150, or the like.

On the other hand, in some embodiments, the optical fingerprint device 130 may include only one optical fingerprint sensor, where the area of the fingerprint detection area 103 of the optical fingerprint device 130 is small and the position is fixed, so that the user needs to press a finger to a specific position of the fingerprint detection area 103 when performing a fingerprint input, otherwise the optical fingerprint device 130 may not acquire a fingerprint image and the user experience is poor. In other alternative embodiments, optical fingerprint device 130 may specifically include a plurality of optical fingerprint sensors; the plurality of optical fingerprint sensors may be disposed side by side below the display screen 120 in a splicing manner, and sensing areas of the plurality of optical fingerprint sensors jointly form the fingerprint detection area 103 of the optical fingerprint device 130. That is, the fingerprint detection area 103 of the optical fingerprint device 130 may include a plurality of sub-areas, each of which corresponds to a sensing area of one of the optical fingerprint sensors, so that the fingerprint collection area 103 of the optical fingerprint device 130 may be extended to a main area of a lower half portion of the display screen, i.e., to a region where a finger is normally pressed, thereby implementing a blind-touch fingerprint input operation. Alternatively, when the number of optical fingerprint sensors is sufficient, the fingerprint detection area 103 may also be extended to half the display area or even the entire display area, thereby enabling half-screen or full-screen fingerprint detection.

It should also be understood that in the embodiments of the present application, the sensing array in the optical fingerprint device may also be referred to as a pixel array, and the optical sensing unit or the sensing unit in the sensing array may also be referred to as a pixel unit or a pixel.

It should be noted that, optical fingerprint device in this application embodiment also can be called optical fingerprint identification module, fingerprint identification device, fingerprint identification module, fingerprint collection device etc. but above-mentioned term mutual replacement.

Fig. 2 shows a schematic cross-sectional view of a fingerprint recognition device.

As shown in fig. 2, the fingerprint identification device 200 includes a microlens array 210, at least one light blocking layer 220, a pixel array 230, and a filter 240.

The microlens array 210 is located right above the pixel array 230 and the at least one light-blocking layer 220, and one microlens 211 corresponds to one pixel unit 231, that is, each microlens 211 in the microlens array 210 focuses the received light to the pixel unit 231 corresponding to the same microlens 211 through the small hole 2201 of the at least one light-blocking layer 220. The optical signal received by each microlens 211 is mainly a fingerprint optical signal incident perpendicularly to the microlens array 210 after being reflected or scattered by a finger above the display screen.

As shown in fig. 2, the pixel array 230 is formed in the substrate 201, and each pixel unit 231 in the pixel array 230 includes a photosensitive area (AA) 2311, where the photosensitive area 2311 may be a photosensitive area of a photodiode for converting a received fingerprint optical signal into a corresponding electrical signal value. A metal wiring layer 233 for transmitting an electrical signal of each pixel unit 231 in the pixel array 230 is formed over the pixel array 230.

Alternatively, as shown in fig. 2, the metal circuit layer 233 is also formed with a small hole, which can be used to transmit the fingerprint light signal to the pixel unit 231. Over the metal line layer 233, a protection layer 234 may be formed, and the protection layer 234 may include: silicon oxide, silicon nitride and/or silicon oxynitride.

It is understood that the substrate 201, the pixel array 230, the metal line layer 233 and the surface protection layer 234 in fig. 2 may be a schematic stacked structure in an image sensor chip, and the embodiment of the present application does not limit the specific image sensor type and the specific chip structure thereof.

Alternatively, a filter 240 may be directly grown above the sensor chip, and the filter 240 may be an infrared cut (IR-cut, IRC) filter for cutting off infrared light, near infrared light, and a part of infrared signals in the environment. Above the filter 240, a transparent dielectric layer and at least one light blocking layer 220 are grown. In some embodiments, the at least one light blocking layer 220 is made of a black glue material for absorbing and blocking light signals.

In the fingerprint identification device 200 of fig. 2, the plurality of microlenses 211 in the microlens array 210 and the plurality of pixel units 231 in the pixel array 230 are in one-to-one correspondence, and the photosensitive areas 2311 of the plurality of pixel units 231 in the pixel array 230 are periodically arranged and uniformly distributed.

However, the photosensitive area of the pixel array 230 is affected by the size of the microlens array 210, and the thickness of the fingerprint identification device 200 is relatively large, which increases the processing difficulty, the cycle time and the cost of the optical path of the fingerprint identification device 200.

In addition, in normal life scenes, such as washing hands, getting up in the morning, plastering fingers, low temperature, and the like, fingers are generally dry, the cuticle is not uniform, and when the fingers are pressed on a display screen, poor contact occurs in local areas of the fingers. When the contact between the dry finger and the display screen is not good, the contrast between the fingerprint ridges and the fingerprint valleys of the fingerprint image in the vertical direction formed by the fingerprint identification device 200 is poor, and the image is blurred to be unable to distinguish the fingerprint lines, so that the fingerprint identification performance of the fingerprint identification device 200 for the dry finger is poor.

In addition, since the optical filter 240 is grown above the sensor chip, the surface of the optical filter 240 generally has a high reflectivity, and the metal wiring layer 234 on the sensor chip also has a high reflectivity for the optical signal, the optical signal is easily reflected between the optical filter 240 and the metal wiring layer 234 to form an optical waveguide effect, and a lot of stray light is generated, and the stray light easily enters into the pixel unit to affect the image quality of the fingerprint identification device.

In addition to the above problems, in the fingerprint identification device 200 of fig. 2, the at least one light-blocking layer 220 made of black glue material has high cost and low processing precision, i.e., the size and position precision of the holes in the light-blocking layer 220 are limited, thereby limiting the overall performance of the fingerprint identification device.

Based on this, this application proposes an improved fingerprint identification device, can solve above-mentioned fingerprint identification device with high costs and not good scheduling problem of performance.

Hereinafter, the fingerprint recognition device according to the embodiment of the present application will be described in detail with reference to fig. 3 to 10.

It should be noted that, for the sake of understanding, the same structures are denoted by the same reference numerals in the embodiments shown below, and detailed descriptions of the same structures are omitted for the sake of brevity.

In addition, the number, arrangement and the like of the pixel units, the microlenses, and the light passing holes on the stop layer in the embodiments of the present application shown below are only exemplary, and should not limit the present application in any way.

Fig. 3 is a schematic cross-sectional view of a fingerprint identification device 300 provided in an embodiment of the present application, and fig. 4 is a schematic top view of the fingerprint identification device 300 provided in an embodiment of the present application. Fig. 3 may be a schematic cross-sectional view taken along a-a' direction in fig. 4.

As shown in fig. 3, the fingerprint recognition device 300 includes:

fingerprint identification module, including a plurality of fingerprint identification units 302, every fingerprint identification unit in these a plurality of fingerprint identification units 302 includes:

a microlens 310;

at least two layers of diaphragm layers, such as the top layer diaphragm layer 320, the middle layer diaphragm layer 340 and the bottom layer diaphragm layer 350 in fig. 3, the at least two layers of diaphragm layers are disposed below the micro lens 310, and each of the at least two layers of diaphragm layers is provided with a light through hole to form a plurality of light guide channels in different directions; in the at least two layers of diaphragm layers, the non-light-transmitting hole area of at least one layer of first diaphragm layer is used for absorbing visible light, and the non-light-transmitting hole area of at least one layer of second diaphragm layer is used for transmitting non-pixel sensitive light;

a plurality of pixel units, for example, two of the

pixel units

331 and 334 are shown in fig. 3, the plurality of pixel units are disposed below the at least two layers of diaphragm layers, the plurality of pixel units are respectively located at the bottoms of the plurality of light guide channels in a one-to-one correspondence manner, and the responsivity of the plurality of pixel units to the non-pixel sensitive light is smaller than a first preset threshold;

the fingerprint light signals returned after being reflected or scattered by the finger above the display screen are converged by the micro lens, wherein a plurality of target fingerprint light signals in different directions are respectively transmitted to the plurality of pixel units through the plurality of light guide channels, and the plurality of target fingerprint light signals are used for detecting fingerprint information of the finger.

In this application, to a plurality of fingerprint identification units in the fingerprint identification module, on vertical space, in some embodiments, the light path structure of every fingerprint identification unit in this a plurality of fingerprint identification units is mutually independent, for example, as two fingerprint identification units shown in fig. 3, the microlens in a fingerprint identification unit transmits the light signal that it received to in its below corresponding pixel.

In other embodiments, the structures of the fingerprint identification units may be staggered with respect to each other. For example, a microlens in one fingerprint identification cell may converge the oblique light signal it receives to a pixel cell below a microlens in an adjacent fingerprint identification cell. In other words, one microlens converges the received oblique light signal to a pixel cell under a microlens adjacent to the microlens.

Specifically, in the lateral space, in some embodiments, as shown in fig. 4, the plurality of fingerprint identification units may be arranged in a square array, and the plurality of microlenses in the plurality of fingerprint identification units form a square array of microlenses, and the centers of four adjacent microlenses form a square.

In other embodiments, the plurality of fingerprint identification units may also be arranged in a diamond array, and the plurality of microlenses in the plurality of fingerprint identification units form a diamond-arranged microlens array, and the centers of four adjacent microlenses form a diamond.

It is understood that, besides the above-mentioned several ways, the multiple fingerprint identification units in the embodiment of the present application may be arranged in any other form in the longitudinal space and the transverse space, and the embodiment of the present application is not particularly limited.

Specifically, in the present application, the microlens 310 may be various lenses having a condensing function for increasing a field of view and increasing an amount of light signals transmitted to the pixel unit. The material of the microlens 310 may be an organic material, such as a resin. Alternatively, the surface of the microlens 310 may be spherical or aspherical. The micro lens 310 may be a circular lens, a square lens, or the like, which is not limited in the embodiments of the present application.

Alternatively, if the micro-lens 310 is a circular micro-lens, the manufacturing cost is lower than that of a square micro-lens, so that the manufacturing cost of the entire fingerprint identification device can be reduced.

Specifically, the diameter of the circular microlens is not more than the arrangement period of the plurality of pixel units. For example, if the area where the plurality of pixel units are located is a quadrilateral area of A × B, where A ≦ B, and A and B are positive integers, the diameter of the microlens 310 is smaller than or equal to A.

In some embodiments, as shown in fig. 4, in the fingerprint identification device, if the plurality of fingerprint identification units are arranged in a square array, the plurality of microlenses in the plurality of fingerprint identification units form a microlens array arranged in a square. In the square microlens array, due to the manufacturing process, there is usually a gap between two adjacent circular microlenses rather than a tangent state, for example, if the gap width is 1 μm, and a plurality of pixel units form an L × L square region, the diameter of the circular microlens is (L-1) μm, and the orthographic projection of the center of the circular microlens on the square region is located at the center of the square region.

Specifically, in the present application, the pixel unit may be a kind of photoelectric conversion unit. Alternatively, the pixel unit may include a Photodiode (PD), a switching tube, and the like, wherein the switching tube is used for receiving a control signal to control the operation of the PD and for controlling an electrical signal output from the PD. Alternatively, the plurality of pixel units in the fingerprint identification unit 302 may be quadrilateral pixel units, such as square pixel units.

As shown in fig. 3, the pixel units may be formed in the substrate by using a semiconductor process, the pixel units in the fingerprint identification units may form a pixel array, the pixel array is electrically connected by one or more metal wiring layers (e.g., the metal wiring layer 335 shown in fig. 3), the one or more metal wiring layers, the pixel array, the substrate, etc. may form an image sensor chip 330, which may be a CMOS image sensor or a CCD sensor, and it is understood that the image sensor may include necessary dielectric layers or other stacked structures besides the metal wiring layers, the pixel array, and the substrate, for example, a dielectric layer between one or more metal layers, and a protective layer above the topmost metal layer, etc., which may be referred to related descriptions in the prior art, this is not described in detail in the present application.

Specifically, in the present application, at least two diaphragm layers may be filter material layers that transmit optical signals in a target wavelength band and cut off optical signals in a non-target wavelength band, and light passing holes are provided therein to limit light beams to realize imaging.

The at least two layers of diaphragm layers include at least one first diaphragm layer, and the non-light-passing hole area of the first diaphragm layer is used for absorbing visible light, for example, the first diaphragm layer may be an infrared light transmission (IR-pass, IRP) visible light cut-off filter layer, the infrared light transmission visible light cut-off filter layer is combined with an infrared light cut-off filter layer above the fingerprint identification unit, all visible light and infrared light signals can be cut off, so that the combination of the visible light cut-off filter layer and the infrared light cut-off filter layer can achieve a good light blocking effect.

And, compare in fig. 2 that the layer 220 material that is in the light of being in the light is the blackfilled compound material, the cost on the first diaphragm layer of at least one deck in this application is lower, and the machining precision is high, can improve the uniformity and the production yield of product, in other words, the size and the position of the logical unthreaded hole in this at least one deck first diaphragm layer all can accurate control to can improve the control accuracy to light guide channel, promote fingerprint identification device's wholeness ability. Through the technical scheme of this application, can further reduce fingerprint identification device's cost and improve fingerprint identification device's performance under can guaranteeing good light blocking's the condition.

Further, the at least two diaphragm layers further include at least one second diaphragm layer, and the at least one second diaphragm layer is configured to transmit non-pixel-sensitive light, which is a light signal to which the pixel unit is not sensitive, that is, the pixel unit has a smaller or no response to the non-pixel-sensitive light, for example, smaller than a first preset threshold. In other words, even if the pixel unit receives the non-pixel sensitive light, the pixel unit does not convert the non-pixel sensitive light into an electrical signal or the converted electrical signal is small.

By way of example, the non-pixel sensitive light may be a first color light including, but not limited to, blue light, or may also be a light signal of another color.

Optionally, in this embodiment of the application, the first preset threshold may be less than or equal to 10%, and the responsivity of the pixel unit to the light of the first color is less than 10%, and as an example, the quantum efficiency of the pixel unit to the blue light is less than 10%.

Further, the non-light-transmitting hole region of the at least one second aperture layer is used for absorbing the pixel-sensitive light while transmitting the non-pixel-sensitive light, and the non-light-transmitting hole region of the at least one second aperture layer has a larger absorptivity to the pixel-sensitive light, for example, larger than a third preset threshold.

The pixel sensitive light is a light signal to which the pixel unit is sensitive corresponding to the pixel non-sensitive light, that is, the responsivity of the pixel unit to the pixel sensitive light is relatively large, for example, greater than a second preset threshold, and the second preset threshold is greater than the first preset threshold. In other words, when a pixel element receives the pixel sensitive light, the pixel element responds to the pixel sensitive light and converts it into a corresponding electrical signal.

By way of example, the pixel sensitive light may include a second color light including, but not limited to, green or cyan light, or other light signals different from the first color light.

In some embodiments, the second and third preset thresholds may be greater than or equal to 70%, specifically, the responsivity of the pixel unit to the second color light is greater than 70%, and the absorptivity of the non-light-transmitting aperture area of the second diaphragm layer to the second color light is greater than 70%, as an example, the quantum efficiency of the pixel unit to the green light is greater than 70%, and the absorptivity of the non-light-transmitting aperture area of the second diaphragm layer to the green light is greater than 70%.

By the above description of the second aperture layer, in the embodiment of the present application, the second aperture layer may be an aperture layer made of a second color filter material, for example, it may be a blue filter layer or a filter layer made of a violet filter layer, and the non-light-transmitting hole region is used for transmitting a blue light signal and absorbing a light signal other than blue light.

Compare in figure 2 the layer 220 material that is in the light be the blackfilled compound material, the same cost of at least one deck second diaphragm layer in this application is lower, and the machining precision is high, is favorable to further improving the uniformity and the production yield of product, through the technical scheme of this application, under the condition that can guarantee good light blocking, further reduces fingerprint identification device's cost and promotes fingerprint identification device's performance.

It should be understood that the numerical values of the first preset threshold, the second preset threshold, and the third preset threshold are all exemplary illustrations, and the embodiment of the present application does not limit the specific numerical values thereof.

In this embodiment, by designing a combination of corresponding aperture layers for the response characteristics of the pixel cells in the fingerprint recognition unit 302, the influence of stray light on the pixel cells can be reduced while reducing the cost, and the imaging quality can be further improved.

Moreover, in the embodiment of the present application, the pixel units in the fingerprint identification unit 302 have the highest responsivity to green light or cyan light, and the fingerprint image generated by the pixel array formed by the plurality of fingerprint identification units 302 has better quality and higher contrast.

Furthermore, the pixel unit in the fingerprint identification unit 302 may have the highest responsivity to green light or cyan light, and when performing fingerprint identification, the light source may emit a light signal of green or cyan, and may further reduce stray light signals of other wavelength bands.

Of course, the light source may also emit other light signals including a green light signal, such as a white light signal, etc., which is not limited in the embodiments of the present application.

Alternatively, as shown in fig. 5, if the fingerprint identification device is disposed below the display screen 120 and the light source of the fingerprint identification device is the display screen 120 when performing fingerprint identification, the light emitting area 121 of the display screen displays a green, cyan or white light spot corresponding to the position pressed by the finger or the fingerprint detection area of the fingerprint identification device when performing fingerprint identification, so as to provide the light source for fingerprint identification.

Taking green light signals emitted by a light source as an example, after green fingerprint light signals returned after being reflected or scattered by a finger are converged by a micro lens, a plurality of green target fingerprint light signals in different directions are respectively transmitted to a plurality of pixel units through a plurality of light guide channels, and the plurality of green target fingerprint light signals are used for detecting fingerprint information of the finger.

Optionally, as shown in fig. 5, the fingerprint identification device 300 may include an ir-cut filter 301, where the ir-cut filter 301 is disposed in an optical path from the display screen 120 to a plurality of pixel units in the fingerprint identification module.

In this application, infrared cut-off filter 301 is arranged in preventing that the infrared light signal in the environment from entering into the fingerprint identification module, influences the fingerprint identification result. Further, the ir-cut filter 301 can also prevent the near-infrared light signal and part or all of the red light signal in the visible light from entering the pixel unit, for example, the ir-cut filter 301 can be used to cut off red light and infrared light above the wavelength band of 620nm from entering the pixel unit.

In one embodiment, the infrared cut filter 301 may be disposed on a surface of an image sensor chip where a plurality of pixel units are located, and the manner of disposing may be described with reference to fig. 2.

Preferably, in another embodiment, as shown in fig. 5, the infrared cut filter 301 may be disposed above the fingerprint recognition module.

Optionally, this infrared cut-off filter 301 is unsettled to be set up in fingerprint identification module top, and it can utilize support and/or glue film to be fixed in the marginal area of fingerprint identification module, also can be fixed in the display screen below, and this application embodiment does not do the injecing to its concrete fixed mode, and it only need be located between display screen and the fingerprint identification module can.

Compared with the optical filter 240 in fig. 2, the infrared cut-off optical filter 301 is suspended above the fingerprint identification module, so that the optical signal can be prevented from being reflected between the optical filter and the metal layer to form stray light.

The basic imaging principle of the fingerprint identification device of the embodiment of the present application and at least two layers of diaphragm layers are briefly described above, and the structure of the fingerprint identification device of the embodiment of the present application is specifically discussed below with reference to fig. 3 to 9.

In this embodiment of the application, in order to form N light guide channels in at least two diaphragm layers, N light passing holes may be disposed in at least one target diaphragm layer of the at least two diaphragm layers, and correspond to N pixel units below the diaphragm layers one to one, where N is a positive integer greater than 1. For example, N light-passing holes may be provided in the bottom diaphragm layer of at least two diaphragm layers, one for each of the N pixel units.

Optionally, one or more of the at least one target stop layer is a first stop layer.

Optionally, in at least two of the diaphragm layers, except the first diaphragm layer, the other diaphragm layers are the second diaphragm layer.

Furthermore, in addition to the target diaphragm layer, M light-passing holes may be formed in other diaphragm layers of the at least two diaphragm layers, where M is greater than or equal to 1 and less than or equal to N, and M is a positive integer.

Optionally, in at least two diaphragm layers, the number of light-passing holes in the upper diaphragm layer is less than or equal to the number of light-passing holes in the lower diaphragm layer.

Optionally, in at least two diaphragm layers, the aperture of the light through hole in the upper diaphragm layer is larger than that of the light through hole in the lower diaphragm layer, in other words, in the plurality of light guide channels, the aperture of the light through hole decreases from top to bottom in sequence.

Optionally, in at least two-layer diaphragm layer, logical unthreaded hole is the circular port, compares in quad slit or dysmorphism hole, leads to the unthreaded hole and adopts the circular port, can guarantee the symmetry when light signal gets into logical unthreaded hole, guarantees image imaging quality.

As an example, in at least two layers of diaphragm layers, one light through hole is arranged in the top diaphragm layer, and N light through holes are arranged in all the other diaphragm layers except the top diaphragm layer to form N light guide channels.

As another example, in the at least two diaphragm layers, N light-passing holes are also provided in the top diaphragm layer, that is, in this example, N light-passing holes are provided in each of the at least two diaphragm layers to form N light-guiding channels.

Of course, in addition to the two examples, the light-passing holes may be arranged in other manners, for example, in at least two layers of diaphragm layers, except that N light-passing holes are arranged in the bottom diaphragm layer, only one light-passing hole is arranged in each of the other diaphragm layers to form N light-guiding channels. The embodiment of the application does not specifically limit the specific arrangement of the light through holes in at least two layers of diaphragm layers, and only needs to form N light guide channels.

In some embodiments, as shown in fig. 3, in the fingerprint identification unit 302, at least two layers of diaphragm layers are three layers of diaphragm layers, wherein one light-passing hole is disposed in the top layer diaphragm layer 320 located at the uppermost layer, and a plurality of light-passing holes corresponding to a plurality of pixel units are disposed in each of the middle layer diaphragm layer 340 and the bottom layer diaphragm layer.

Specifically, the filter material of the non-light-passing aperture region of the top stop layer 320 is located at the edge portion of the microlens 310, and is used for blocking stray light at the edge portion of the microlens 310. The reasonable increase of the aperture of the light-transmitting hole in the first diaphragm layer 320 helps to increase the total light-entering amount and improve the imaging quality.

The filter material in the non-light-passing aperture region of the intermediate layer stop layer 340 is used to further absorb and block other stray light, where the plurality of light-passing apertures are used to form a plurality of light-guiding channels corresponding to the plurality of pixel units.

The filter material in the non-light-passing hole region of the bottom layer stop layer 350 is used to absorb or transmit the stray light reflected by the uppermost metal layer (e.g., the metal wiring layer 335 in fig. 3) of the chip where the pixel unit is located, and the plurality of light-passing holes therein are matched with the plurality of light-passing holes in the previous layer to form a plurality of light-guiding channels with higher direction accuracy, so that the imaging quality can be further improved.

In some embodiments, the three layers of diaphragm layers may be all the first diaphragm layers, and the non-light-transmitting hole regions thereof are used for absorbing visible light. For example, the non-light-transmitting hole areas of the three diaphragm layers can be all infrared light transmitting visible light cut-off filter layers. With this configuration, the non-light-passing hole region of the bottom stop layer 350 in the lowermost layer can absorb or transmit stray light to a greater extent, which contributes to a greater improvement in imaging quality.

In other embodiments, one or both of the three aperture layers is a first aperture layer.

Specifically, the middle diaphragm layer 340 of the three diaphragm layers is the first diaphragm layer, and/or the bottom diaphragm layer is the first diaphragm layer, so as to play a good light blocking role and form a light guide channel.

As an example, the intermediate diaphragm layer 340 is a first diaphragm layer, e.g., an infrared light transmitting visible light cut filter, and the top diaphragm layer 320 and the intermediate diaphragm layer 350 are second diaphragm layers, e.g., blue diaphragm layers.

After the optical signal is converged by the micro lens 310, most of the visible light in the wavelength band is blocked by the filter material of the top layer diaphragm layer 320, only part of the non-sensitive light of the pixel is transmitted, all the visible light is blocked at the filter material of the middle layer diaphragm layer 340, and a plurality of light guide channels are formed, the stray light transmitted to the pixel unit by the micro lens is further blocked at the filter material of the bottom layer diaphragm layer 350, and the stray light reflected by the metal layer of the chip where the pixel unit is located is absorbed, so that the imaging quality is improved.

It will be appreciated that the bottom stop layer 350 needs to be located close to the metal layer of the chip to enhance its effect of absorbing stray light, for example, it is located 1 μm to 3 μm above the chip.

Fig. 6 shows the relevant structural parameters of three layers of diaphragm layers when at least two layers of diaphragm layers are three layers of diaphragm layers.

As shown in fig. 6, in the fingerprint identification unit 302, a plurality of pixel units are formed in the sensor chip 330, and the diameter of the microlens 310 is D, it can be understood that if the microlens 310 is a spherical microlens and the lower surface of the microlens 310 is circular, the diameter D of the microlens 310 can be the diameter of the circular lower surface of the microlens 310. If the microlens 310 is an aspheric microlens, the diameter D of the microlens 310 can be the maximum diameter of the lower surface of the microlens 310.

As shown in fig. 6, the height of the optical path between the lower surface of the microlens 310 and the upper surface of the sensor chip 330 is H, the height of the optical path between any one of the diaphragm layers and the upper surface of the sensor chip 330 is H, and the aperture D of the light-passing hole in the any one of the diaphragm layers is in the range of (1 ± 0.3) × D × H/H.

For example, in FIG. 6, the diameter of the light-passing hole in the bottom stop layer 350 is d₃The height of the optical path between the bottom diaphragm layer 350 and the upper surface of the sensor chip 330 is h₃Then d is₃At (1. + -. 0.3). times.Dxh₃between/H, similarly, the diameter of the light-passing hole in the intermediate layer diaphragm layer 340 is d₂The height of the optical path between the intermediate layer diaphragm layer 340 and the upper surface of the sensor chip 330 is h₂Then d is₂At (1. + -. 0.3). times.Dxh₂between/H, the diameter of the light-passing hole in the top diaphragm layer 320 is d₁The height of the optical path between the top diaphragm layer 320 and the upper surface of the sensor chip 330 is h₁Then d is₁At (1. + -. 0.3). times.Dxh₁between/H.

It should be noted that, according to the above calculation method of the aperture of the light transmitting hole, if a plurality of light transmitting holes are formed in one layer of the diaphragm layer and overlap exists between the light transmitting holes, the light transmitting holes form one light transmitting hole with a large aperture.

With continued reference to FIG. 6, in some embodiments, the optical path height h between the bottom stop layer 350 and the upper surface of the sensor chip 330₃The optical path height H between 0 and H/3 and the distance between the middle layer diaphragm layer 340 and the upper surface of the sensor chip 330₂The height H of the optical path between the top diaphragm layer 320 and the upper surface of the sensor chip 330 can be designed to be between H/5 and 2H/3₁Can be designed between H/2 and H.

It is understood that in this embodiment, the bottom layer of the aperture layer is located below the middle layer of the aperture layer, and the middle layer of the aperture layer is located below the top layer of the aperture layer. As an example, if the bottom stop layer 350 is at the height h of the optical path between the top surface of the sensor chip 330 and the bottom stop layer 350₃H/3, when the intermediate diaphragm layer is disposed above the bottom diaphragm layer to satisfy the above design condition, the optical path height H between the intermediate diaphragm layer 340 and the upper surface of the sensor chip 330₂Can be designed between H/3 and 2H/3.

In another embodiment of the method of the present invention,height h of light path between bottom diaphragm layer 350 and upper surface of sensor chip 330₃Can be designed between 0 and H/3; alternatively, the optical path height h between the intermediate layer diaphragm layer 340 and the upper surface of the sensor chip 330₂Can be designed between H/5 and 2H/3; alternatively, the height h of the optical path between the top stop layer 320 and the upper surface of the sensor chip 330₁Can be designed between H/2 and H.

It can also be understood that fig. 6 only illustrates a case where at least two diaphragm layers are three diaphragm layers, and when at least two diaphragm layers are other diaphragm layers, the size of the light-passing hole in any one diaphragm layer and the position of the diaphragm layer may refer to the above description, which is not repeated herein.

A schematic top view of one of the fingerprint identification units 302 of figure 3 is shown in figure 7.

In this embodiment of the application, it is described that the fingerprint identification unit 302 includes 4 pixel units, and optionally, the fingerprint identification unit 302 may further include 2 pixel units or 3 pixel units, or even a greater number of pixel units, which is not limited in this embodiment of the application.

As shown in fig. 7, the 4 pixel units in the fingerprint identification unit 302 are a first pixel unit 331, a second pixel unit 332, a third pixel unit 333 and a fourth pixel unit 334, respectively.

Correspondingly, in the fingerprint identification unit, light-passing holes in at least two layers of diaphragm layers form 4 light-guiding channels in different directions, and light-sensing areas in the 4 pixel units are respectively used for receiving 4 target fingerprint light signals passing through the 4 light-guiding channels.

As shown in fig. 3 and 7, an 11# light passing hole 321 is formed in the top diaphragm layer 320, and four light passing holes are formed in the intermediate diaphragm layer 340 and the bottom diaphragm layer 350, specifically, the four light passing holes in the intermediate diaphragm layer 340 are a 21# light passing hole 341, a 22# light passing hole 342, a 23# light passing hole 343 and a 24# light passing hole 344, respectively, and the four light passing holes in the bottom diaphragm layer 350 are a 31# light passing hole 351, a 32# light passing hole 352, a 33# light passing hole 353 and a 34# light passing hole 354, respectively.

The 11# light passing hole 321, the 21# light passing hole 341, and the 31# light passing hole 351 form a first light guide channel through which the first target fingerprint light signal of the first direction is transmitted to the first pixel unit 331.

Similarly, the above-mentioned 11# clear aperture 321, 22# clear aperture 342 and 32# clear aperture 352 form a second light guide channel through which the second target fingerprint light signal of the second direction is transmitted to the second pixel unit 332.

The aforementioned 11# light passing hole 321, 23# light passing hole 343 and 33# light passing hole 353 form a third light guiding channel through which a third target fingerprint light signal of a third direction is transmitted to the third pixel unit 333.

The aforementioned 11# light passing hole 321, 24# light passing hole 344, and 34# light passing hole 354 form a fourth light guide channel through which a fourth target fingerprint light signal of a fourth direction is transmitted to the fourth pixel unit 334.

Alternatively, the direction of the light guide channel may be a direction of a central line of all or part of the light through holes on the light guide channel, or the direction of the light guide channel is a direction close to the central line, for example, the direction of the light guide channel and the direction of the central line are within ± 5 °. In the present application, the direction of the light guide channel is the same as or similar to the direction of the target fingerprint light signal received by the light guide channel.

Another schematic top view of one of the fingerprint recognition units 302 of fig. 3 is shown in fig. 8.

The structure of the fingerprint identification unit 302 in fig. 8 is similar to the structure of the fingerprint identification unit 302 in fig. 7 above, and the related schemes can be described above. The fingerprint identification unit in fig. 7 and 8 is different in that the positions of the light-passing holes in the three layers of the diaphragm layers in fig. 8 are different from the positions of the light-passing holes in the three layers of the diaphragm layers in fig. 7.

Taking the first light guiding channel corresponding to the first pixel unit 331 in fig. 7 and 8 as an example, if an angle between a line connecting a center of the 31# light-passing hole 351 corresponding to the first pixel unit 331 in the bottom stop layer 350 in fig. 7 and a center of the 21# light-passing hole 341 corresponding to the first pixel unit 331 in the middle stop layer 340 and a vertical direction is a first angle, and an angle between a line connecting a center of the 31# light-passing hole 351 corresponding to the first pixel unit 331 in the bottom stop layer 350 in fig. 8 and a center of the 21# light-passing hole 341 corresponding to the first pixel unit 331 in the middle stop layer 340 and a vertical direction is a second angle, the first angle is smaller than the second angle. In the present application, the vertical direction is a direction perpendicular to the plane of the display screen, and the horizontal direction is a direction parallel to the plane of the display screen.

Thus, the angle at which the first light guide channel receives the first target fingerprint light signal in fig. 7 is smaller than the angle at which the first light guide channel receives the first target fingerprint light signal in fig. 8. Similarly, the angles of the target fingerprint light signals received by the other light-guiding channels in fig. 7 are also smaller than the angles of the target fingerprint light signals received by the other light-guiding channels in fig. 8.

The fingerprint identification device provided by the figure 8 is adopted, and the light guide channel with a large angle is arranged, so that a target fingerprint light signal with a large angle can be received, the detection of dry fingers is facilitated, and the height of a light path is reduced.

Optionally, the aperture of the light through hole in the light guide channel decreases from top to bottom. For example, in the first light guide channel, the aperture of the 11# light passing hole 321, the 21# light passing hole 341 and the 31# light passing hole 351 from top to bottom are sequentially reduced.

In this embodiment, each light-passing hole may be located at any position below the microlens 310, and is intended to form any four light-guiding channels, and the included angles between the four light-guiding channels in different directions and the display screen may be completely the same or may not be completely the same. In other words, the first pixel unit 331, the second pixel unit 332, the third pixel unit 333, and the fourth pixel unit 334 corresponding to the microlens 310 may also be located at any position below the microlens 310, and are intended to receive target fingerprint light signals of four different directions passing through light guide channels of four different directions.

Further, as shown in fig. 7 and 8, the 4 pixel units are respectively provided with a first photosensitive region 3311, a second photosensitive region 3321, a third photosensitive region 3331 and a fourth photosensitive region 3341.

In one possible implementation, the photosensitive area in the 4 pixel units occupies only a small area in the pixel units to meet the requirement of receiving the optical signal.

In this embodiment, the center of the first photosensitive region 3311 may be located at the bottom of the first light guide channel, for example, the center of the first photosensitive region 3311 may be located on the line connecting the plurality of light holes in the first light guide channel. Similarly, the centers of the photosensitive regions in other pixel units can be located at the bottom of the corresponding light guide channels.

With the above arrangement, the first target fingerprint light signal forms a first light spot on the first pixel unit 331 through the first light guide channel, and the first light sensing area 3311 in the first pixel unit 331 can completely cover the first light spot for maximum reception of the first target fingerprint light signal. Similarly, the photosensitive areas in other pixel cells may also completely cover the light spot formed by the target fingerprint light signal.

Alternatively, if the first pixel unit 331 can be a quadrilateral area among four pixel units, the length and width of the first pixel unit 331 are L and W, respectively, where W is less than or equal to L, and W and L are positive numbers, and both the length and width of the first photosensitive area 3311 in the first pixel unit 331 are greater than or equal to 0.1 × W. Of course, the sizes of the other three pixel units and the photosensitive area in the four pixel units may also correspondingly satisfy the above conditions.

In this case, the photosensitive area in the pixel unit is small, but the fingerprint optical signal passing through the light guide channel is sufficiently received, so that the fingerprint imaging requirement is met, and meanwhile, the area of other areas in the pixel unit is large, so that enough space is provided for the wiring of the pixel unit, the process requirement is reduced, the process manufacturing efficiency is improved, and other areas can be used for arranging other circuit structures, so that the signal processing capacity of the pixel unit can be improved.

As shown in fig. 7 and 8, in the embodiment of the present application, the centers of the regions where the 4 pixel units are located coincide with the center of the microlens in the vertical direction, and the 4 photosensitive regions of the 4 pixel units are disposed offset from the centers of the four pixel units.

Alternatively, the 4 photosensitive areas are offset from the center of the pixel unit and are also offset away from the center of the microlens, so that the target fingerprint optical signal angle received by the 4 photosensitive areas can be increased, and the thickness of the fingerprint identification unit can be further reduced. In the fingerprint identification unit shown in fig. 5, 4 photosensitive regions are respectively located at four corners of the region where the 4 pixel units are located.

It should be understood that, in the embodiment of the present application, the 4 photosensitive regions may also be respectively located at the centers of the 4 pixel units, and in order to meet the requirement of the photosensitive regions for receiving the light signals at an angle, the four pixel units may be shifted away from the center of the microlens (the center of the region where the 4 pixel units are located and the center of the microlens are not aligned in the vertical direction), so as to increase the angle of the target fingerprint light signals received by the four photosensitive regions, and decrease the thickness of the fingerprint identification unit.

In the embodiment of the above application, the photosensitive regions in the 4 pixel units occupy only a small part of the area in the pixel units, and in another possible implementation, the photosensitive regions in the 4 pixel units occupy most of the area in the pixel units, so as to improve the dynamic range of the pixel units.

For example, the photosensitive area in 4 pixel units covers other areas besides the light spot on the pixel unit. Alternatively, the photosensitive regions in the 4 pixel cells occupy most of the area of the pixel cells. For example, the first photosensitive region 3311 in the first pixel unit 331 occupies 95% or more of the area in the first pixel unit 331, or the respective photosensitive regions in the other pixel units occupy 95% or more of the area.

In this embodiment, the photosensitive area of the pixel unit is increased, and the full-well capacity and the dynamic range of the pixel unit can be increased, thereby improving the overall performance of the pixel unit and realizing high dynamic range imaging (HDR) of the fingerprint recognition device.

In the embodiment of the present application, 4 pixel units may be disposed at any position below the microlens, and the 4 pixel units form a pixel region of a quadrilateral region, and a center point of the pixel region coincides or does not coincide with a center of the microlens in a vertical direction. And 4 photosensitive regions may be disposed at any position in the 4 pixel units, and are intended to receive target fingerprint optical signals passing through four channels.

According to the scheme of the embodiment of the application, one micro lens corresponds to a plurality of pixel units, the plurality of pixel units respectively receive fingerprint optical signals in a plurality of directions which are converged by the micro lens and pass through a plurality of light guide channels, and the fingerprint optical signals in the plurality of directions are respectively received by the plurality of pixel units. Compared with the technical scheme that one microlens corresponds to one pixel unit (such as the fingerprint identification device in fig. 2), the light-entering amount of the fingerprint identification device can be increased, the exposure time can be shortened, and the visual field of the fingerprint identification device can be increased.

In addition, in the embodiment of the present application, the angle of the fingerprint optical signal received by the photosensitive region in the plurality of pixel units (the included angle between the fingerprint optical signal and the direction perpendicular to the display screen) is determined by the relative position relationship between the plurality of photosensitive regions and the microlens, and the farther the photosensitive region is shifted from the center of the microlens, the larger the angle of the fingerprint optical signal received by the photosensitive region is. Therefore, the positions of the pixel units and/or the photosensitive areas are flexibly set, so that the photosensitive areas can receive fingerprint optical signals with large angles, the identification problem of dry fingers is further improved, the thickness of an optical path in the fingerprint identification unit can be further reduced, the thickness of the fingerprint identification device is reduced, and the process cost is reduced.

In addition, the diaphragm layer in the embodiment of the application is lower than the cost of traditional black glue materials, and the machining precision is high, in other words, the size and the position of the light through hole in the diaphragm layer can be accurately controlled, so that the control precision of the light guide channel can be improved, and the overall performance of the fingerprint identification device is improved.

To sum up, by adopting the technical scheme of the embodiment of the application, the whole light incoming quantity of the fingerprint identification device is improved, the identification problem of a dry finger is improved, the thickness of a light path is reduced, the performance of the fingerprint identification device is comprehensively improved, meanwhile, the manufacturing process precision of the fingerprint identification device can be improved, the process cost is reduced, and the fingerprint identification device in the embodiment of the application has wider application scenes at low cost and is favorable for the light and thin development of electronic equipment where the fingerprint identification device is located.

Optionally, the target fingerprint optical signals in multiple directions received by the fingerprint identification unit 302 are all optical signals inclined with respect to the display screen, or one of the target fingerprint optical signals in multiple directions is an optical signal inclined perpendicular to the display screen, and the other target fingerprint optical signals are optical signals inclined with respect to the display screen.

In other words, in the fingerprint identification unit 302, the directions of the plurality of light guide channels in different directions formed in at least two diaphragm layers are all inclined directions relative to the display screen. Or, the direction of one light guide channel in the plurality of light guide channels in different directions is a direction perpendicular to the display screen, and the directions of the other light guide channels are directions inclined relative to the display screen.

Alternatively, the angle of the target fingerprint light signal of the plurality of directions (the angle between the target fingerprint light signal and the direction perpendicular to the display screen) may be between 10 ° and 45 °.

It should be understood that, in a specific implementation, a person skilled in the art may determine the direction of the light guide channel according to the light path design requirement, so as to determine the distribution of the light through holes in at least two layers of the diaphragm layers, form a light guide channel meeting the light path design requirement, and receive the target fingerprint light signal passing through a specific direction by the pixel unit.

By selecting the target fingerprint optical signal between 10 degrees and 45 degrees to be received by the pixel unit through the light guide channel, the optical path height of the fingerprint identification device can be reasonably controlled within 30 mu m, and the duty ratio of the micro-lens array can be improved to the maximum extent.

In the fingerprint identification device 300 and the fingerprint identification unit 302 shown in fig. 3 to 8, at least two layers of diaphragm layers are three layers of diaphragm layers, and optionally, at least two layers of diaphragm layers can also be two layers of diaphragm layers.

Figure 9 shows a schematic cross-sectional view of another fingerprint recognition device.

As shown in fig. 9, in a fingerprint identification unit 302, it includes only a top layer of apertures 370 and a bottom layer of apertures 380.

In some embodiments, the top stop layer 370 and the bottom stop layer 380 may also be both the first stop layer, for example, the non-light-passing hole areas may be both infrared light-transmitting visible light-cutting filter layers.

In other embodiments, the top stop layer 370 may be a second stop layer, for example, a blue filter layer in the non-light-transmitting aperture region, and the bottom stop layer 380 may be a first stop layer, for example, a visible light-transmitting infrared light-blocking filter layer in the non-light-transmitting aperture region.

In the above embodiment, the non-light-passing aperture region of the bottom layer stop layer 380, while serving to block visible light and form 4 light-guiding channels, also serves to absorb stray light signals reflected from the metal layer below it. When the period of the pixel unit is greater than a certain threshold value, the scheme of the embodiment is adopted, and the cost of the fingerprint identification device can be further reduced by reducing the number of layers of the diaphragm layer on the premise of ensuring the imaging quality.

Alternatively, in the embodiment of the present application, the height of the optical path between the lower surface of the microlens 310 and the upper surface of the sensor chip 330 is H,

the distance between the bottom stop layer 380 and the upper surface of the sensor chip 330 is H/5 to 2H/3, and the distance between the top stop layer 370 and the upper surface of the sensor chip 330 is H/2 to H.

It is understood that in this embodiment, the bottom layer of the aperture layer is located below the top layer of the aperture layer. As an example, if the distance between the bottom layer stop layer 380 and the upper surface of the sensor chip 330 is 2H/3, the distance between the top layer stop layer 370 and the upper surface of the sensor chip 330 may be designed to be 2H/3 to H in order to satisfy the above-described design conditions and to dispose the bottom layer stop layer above the bottom layer stop layer.

In another embodiment, the distance between the bottom stop layer 380 and the upper surface of the sensor chip 330 is between H/5 and 2H/3, or the distance between the top stop layer 370 and the upper surface of the sensor chip 330 is between H/2 and H.

It can also be understood that the fingerprint identification apparatus in fig. 9 differs from the fingerprint identification apparatus in fig. 3 only in the number of the diaphragm layers, and the top diaphragm layer 370 in fig. 9 may be the top diaphragm layer 320 in fig. 3, the middle diaphragm layer 340 in the bottom diaphragm layer in fig. 9, and other structures and related technical solutions of the fingerprint identification apparatus in fig. 9 may be referred to the descriptions in fig. 3 to fig. 7 above, and are not described again here.

It is also understood that in the present application, the at least two diaphragm layers may also be 4 diaphragm layers or more than 4 diaphragm layers. Optionally, on the basis of fig. 3, more diaphragm layers may be additionally disposed between the top diaphragm layer 320 and the middle diaphragm layer 340, and/or between the middle diaphragm layer 340 and the bottom diaphragm layer 350, so as to reduce stray light and improve the fingerprint imaging effect.

In the above embodiment, by providing the light-passing holes in each of the at least two diaphragm layers to form a plurality of light-guiding channels in different directions, the number of the light-passing holes on each light-guiding channel is equal to the number of layers of the diaphragm layers.

Optionally, on the basis, more light through holes can be formed on the light guide channel. For example, in the metal wiring layer above the pixel unit, a plurality of light passing holes corresponding to a plurality of light guide channels are also provided.

Referring to fig. 3 and 9, in the fingerprint identification device 300 provided therein, a metal circuit layer 335 is disposed above 4 pixel units in a

sensor chip

330, 4 light-passing holes corresponding to the 4 pixel units are formed in the metal circuit layer 335, the 4 light-passing holes may be all circular holes, and the 4 light-passing holes are disposed below the 4 light-passing holes in the bottom diaphragm layer 350, and form the 4 light-guiding channels together with the light-passing holes in the three diaphragm layers, the light-passing holes in the metal circuit layer 335 do not change the directions of the 4 target fingerprint optical signals passing through the 4 light-guiding channels, and further block stray light and interference light affecting fingerprint identification effects. Specifically, in the metal wiring layer 335, the light passing hole corresponding to the first pixel unit 331 is a # 41 light passing hole 3351, the light passing hole corresponding to the second pixel unit 332 is a # 42 light passing hole 3352, the light passing hole corresponding to the third pixel unit 333 is a # 43 light passing hole 3353, and the light passing hole corresponding to the fourth pixel unit 334 is a # 44 light passing hole 3354.

Optionally, the centers of the 4 light-passing holes in the metal circuit layer 335 may be located on a connection line between the centers of the light-passing holes in the at least two diaphragm layers, or may also be located within a preset range around the connection line. For example, the 11# clear holes 321, 21# clear holes 341, and 31# clear holes 351 form a first light guide channel, the centers of the 11# clear holes 321, 21# clear holes 341, and 31# clear holes 351 are located on a first straight line corresponding to the first pixel unit 331, the center of the 41# clear hole 3351 corresponding to the first pixel unit 331 in the metal wiring layer 335 is also located on the first straight line, or the center of the 41# clear hole 3351 may be located within a predetermined range around the first straight line.

Alternatively, the diameters of the 4 light-passing holes in the metal circuit layer 335 may be smaller than the diameters of the light-passing holes in the bottom diaphragm layer in at least two diaphragm layers, for example, if the fingerprint identification unit 302 includes three diaphragm layers, the diameters of the 4 light-passing holes in the metal circuit layer 335 may be smaller than the diameters of the 4 light-passing holes in the third diaphragm layer 350. For another example, if the fingerprint identification unit 302 includes two aperture layers, the diameter of the 4 light-passing holes in the metal circuit layer 335 may be smaller than the diameter of the 4 light-passing holes in the second aperture layer 340.

Like this, through set up logical unthreaded hole in the metal wiring layer, be one deck diaphragm layer with the metal wiring layer multiplexing, can further improve light guide channel's leaded light effect to promote the fingerprint identification effect.

With continued reference to fig. 3, in the embodiment of the present application, the fingerprint identification unit 302 may further include, in addition to the above-described microlens 310, three layers of aperture layers (a top layer aperture layer 320, a middle layer aperture layer 340, and a bottom layer aperture layer 350), four pixel units (a first pixel unit 331, a second pixel unit 332, a third pixel unit 333, and a fourth pixel unit 334) in the sensor chip 330, and a metal line layer 335:

a first buffer layer 311 and a second buffer layer 351, wherein the first buffer layer 311 is disposed between the microlens 310 and the top stop layer 320, and is used for connecting the microlens 310 and the top stop layer 320. The second buffer layer 351 is disposed between the sensor chip 330 and the bottom stop layer 350, and is used for connecting the sensor chip 330 and the bottom stop layer 350.

Optionally, the first buffer layer 311 is grown above the top-layer diaphragm layer 320, and the first buffer layer 311 is formed in a light-passing hole in the top-layer diaphragm layer 320, for example, the 11# light-passing hole 321 in fig. 3, in addition to the upper surface of the top-layer diaphragm layer 320.

Alternatively, the surface of the sensor chip 330 is a flat protective layer formed by silicon oxide and/or silicon nitride, the second buffer layer 351 can be grown on the protective layer, and the bottom stop layer 350 can be continuously fabricated on the second buffer layer 351.

It is understood that the first buffer layer 311 and the second buffer layer 351 are both transparent media, which include but are not limited to transparent organic polymer materials, and the refractive index of which includes but is not limited to about 1.55.

Further, between the top layer aperture layer 320 and the middle layer aperture layer 340, a first transparent medium layer 361 may be further formed, and between the middle layer aperture layer 340 and the bottom layer aperture layer 350, a second transparent medium layer 362 may be further formed.

The first transparent medium layer 361 is used for connecting the top layer diaphragm layer 320 and the middle layer diaphragm layer 340, and controlling the optical path height between the top layer diaphragm layer 320 and the middle layer diaphragm layer 340 to control the angles of the light guide channel and the target fingerprint light signal.

Alternatively, after the intermediate layer stop layer 340 is grown, a first transparent medium layer 361 is grown on the surface thereof, and the first transparent medium layer 361 is formed in the light passing holes in the intermediate layer stop layer 340, for example, 21# light passing holes 341, 22# light passing holes 342, 23# light passing holes 343, and 24# light passing holes 344 in fig. 3 and 5, in addition to the upper surface of the intermediate layer stop layer 340.

The second transparent medium layer 362 is used to connect the middle layer diaphragm layer 340 and the bottom layer diaphragm layer 350, and control the optical path height between the middle layer diaphragm layer 340 and the bottom layer diaphragm layer 350, so as to further adjust and control the angles of the light guide channel and the target fingerprint optical signal.

Alternatively, after the bottom layer aperture layer 350 is grown, a second transparent medium layer 362 is grown on the surface thereof, and the second transparent medium layer 362 is formed in the light passing holes in the bottom layer aperture layer 350 in addition to the upper surface of the bottom layer aperture layer 350, for example, the 31# light passing hole 351, the 32# light passing hole 352, the 33# light passing hole 353 and the 34# light passing hole 354 in fig. 3 and 5.

It is understood that the first transparent medium layer 361 and the second transparent medium layer 362 are both transparent media, and include, but are not limited to, transparent organic polymer materials, which have refractive indexes similar to those of the first buffer layer 311 and the second buffer layer 351 (the difference between the refractive indexes is smaller than a predetermined threshold), for example, the refractive indexes of the first transparent medium layer 361 and the second transparent medium layer 362 may also be about 1.55.

Similarly, referring to fig. 9, the fingerprint identification unit 302 may further include, in addition to the above-described microlens 310, three layers of aperture layers (a top layer aperture layer 370 and a bottom layer aperture layer 380), four pixel units in the sensor chip 330, and the metal wiring layer 335:

a first buffer layer 311 and a second buffer layer 351, wherein the first buffer layer 311 is disposed between the microlens 310 and the top stop layer 370, and is used for connecting the microlens 310 and the top stop layer 370. The second buffer layer 351 is disposed between the sensor chip 330 and the bottom stop layer 380, and is used to connect the sensor chip 330 and the bottom stop layer 380.

Further, a first transparent medium layer 361 may be further formed between the top stop layer 370 and the bottom stop layer 380.

Specifically, the technical solutions related to the first buffer layer 311, the second buffer layer 351 and the first transparent dielectric layer may refer to the above description, and are not described herein again.

In the above-mentioned embodiments, the design of each layer structure in the fingerprint identification unit 302 and its related parameters are verified through a lot of experiments to optimize the quality of the fingerprint image and reduce the thickness of the fingerprint identification device. For example, the top layer diaphragm layer (e.g., the top layer diaphragm layer 320) of the at least two diaphragm layers has a ratio of the aperture of the light passing hole (e.g., the 11# light passing hole 321) to the microlens period between the preset thresholds to balance the amount of incoming light and block stray light. For another example, the sizes and positions of the light-passing holes in at least two diaphragm layers except the top diaphragm layer are designed to ensure that the light-passing holes smoothly transit to the inside of the sensor chip along the center of the received light so as to ensure the imaging quality. In addition, the curvature radius of the micro lens is designed, so that the fingerprint can be better imaged in an imaging area of the sensor chip, namely the diameter of a diffuse spot imaged by the fingerprint object space image point on the sensor chip is as small as possible.

The basic structure of the fingerprint identification device 300 in the present application is described above with reference to fig. 3 to 9, and further, by introducing a processing method of pixel values in the fingerprint identification device 300, it is able to avoid generating moire fringes in a fingerprint image, and improve the quality of the fingerprint image and the image processing speed to improve the user experience.

In the embodiment of the present application, the fingerprint identification unit 302 includes 4 pixel units for illustration.

It is understood that if a plurality of fingerprint identification units 302 are included in the fingerprint identification device 300, and each fingerprint identification unit includes 4 pixel units, all the pixel units may form a pixel array of the fingerprint identification device 300.

Fig. 10 shows a schematic diagram of a pixel array 303 in a fingerprint recognition device 300. As shown in fig. 10, the numeral "1" denotes the first pixel unit 331, the numeral "2" denotes the second pixel unit 332, the numeral "3" denotes the third pixel unit 333, and the numeral "4" denotes the fourth pixel unit 334.

As shown in fig. 10, none of the plurality of first pixel units 331, the plurality of second pixel units 332, the plurality of third pixel units 333, and the plurality of fourth pixel units 334 are adjacent to each other.

It should be understood that fig. 10 is only a schematic arrangement diagram of a pixel array 303, and in a fingerprint identification unit, the relative position relationship among the first pixel unit 331, the second pixel unit 332, the third pixel unit 333, and the fourth pixel unit 334 may be changed, for example, the position of the first pixel unit 331 in the figure may also be the second pixel unit 332, or the third pixel unit 333, or the fourth pixel unit 334, which is not limited in this embodiment of the application.

In the pixel array 303, a plurality of first pixel units 331 receive a target fingerprint light signal of one direction, which is used to form a first fingerprint image of a finger. The plurality of second pixel units 332 receive fingerprint light signals of another direction, which are used to form a second fingerprint image of the finger. The plurality of third pixel units 333 receives a third directional fingerprint light signal for forming a third fingerprint image of the finger. The plurality of fourth pixel units 334 receives a fourth direction of fingerprint light signals for forming a fourth fingerprint image of the finger. The first fingerprint image, the second fingerprint image, the third fingerprint image and the fourth fingerprint image can be independently used for fingerprint identification, any two or three of the first fingerprint image, the second fingerprint image, the third fingerprint image and the fourth fingerprint image can be reconstructed, and the reconstructed fingerprint images are subjected to fingerprint identification.

Alternatively, in the pixel array 303, each pixel unit receives the target fingerprint light signal in the corresponding direction to generate an original pixel value, and the schematic diagram of the pixel array 303 shown in fig. 10 can also be regarded as an original image schematic diagram formed by the original pixel values.

The original pixel values formed by the pixel array 303 need to undergo physical pixel synthesis and/or digital pixel synthesis (binning), and the like, and finally form the first fingerprint image, the second fingerprint image, the third fingerprint image, and the fourth fingerprint image for fingerprint identification.

Fig. 11 shows a schematic diagram of an image processing method.

As shown in fig. 11, fig. 1# is a schematic diagram of an original image formed by the pixel array 303 in fig. 10.

In fig. 1, "1" represents an original pixel value generated by the first pixel unit 331, numeral "2" represents an original pixel value generated by the second pixel unit 332, numeral "3" represents an original pixel value generated by the third pixel unit 333, and numeral "4" represents an original pixel value generated by the fourth pixel unit 334.

Optionally, in this embodiment of the present application, the fingerprint identification device 300 includes a first summing and averaging circuit, a second summing and averaging circuit, a third summing and averaging circuit, and a fourth summing and averaging circuit, which are used for performing physical pixel synthesis on the original pixel values.

Specifically, the first summing and averaging circuit is used to connect to a plurality of first pixel cells 331 in the pixel array 302 through metal routing, and will be every X₁×X₂The raw pixel values of the first pixel cells 331 are summed and averaged to form one pixel value in the first intermediate fingerprint image.

Similarly, a second summing and averaging circuit is used to connect to a plurality of second pixel cells 332 in pixel array 302 via metal traces and will be every X₁×X₂The original pixel values of the second pixel elements 332 are summed and averaged to form one pixel value in the second intermediate fingerprint image.

The third summing and averaging circuit is used for connecting to a plurality of third pixel units 333 in the pixel array 302 through metal wiring, and every X₁×X₂The original pixel values of the third pixel elements 333 are summed and averaged to form one pixel value in the third intermediate fingerprint image.

The fourth summing and averaging circuit is used for connecting to a plurality of fourth pixel units 334 in the pixel array 302 through metal wiring, and every X₁×X₂The original pixel values of the fourth pixel elements 334 are summed and averaged to form a pixel value in the fourth intermediate fingerprint image.

Alternatively, the X₁×X₂The first pixel units 331 may be adjacent xs in the first pixel units 331 of the pixel array 302₁×X₂The number of pixel units may be, for example, 4 first pixel units of 2 × 2, or 3 pixel units9 first pixel units of 3, and likewise, the X₁×X₂The second pixel units 332 may be X adjacent pixel units in the second pixel units 332 of the pixel array 302, where X is₁×X₂The third pixel units 333 may be adjacent X's in the third pixel units 333 of the pixel array 302₁×X₂A pixel unit, or the X₁×X₂The fourth pixel unit 334 may be an adjacent X in the fourth pixel units 334 of the pixel array 302₁×X₂A pixel unit, the embodiment of the application is to X₁And X₂And is not particularly limited.

In some embodiments, X₁＝X₂When the fingerprint image is 2, the first intermediate fingerprint image, the second intermediate fingerprint image, the third intermediate fingerprint image and the fourth intermediate fingerprint image can be referred to as a figure # 2 in fig. 11.

Where the pixel value in the first intermediate fingerprint image (denoted as "1 '" in fig. 11) is obtained by summing and averaging the 2 × 2 original pixel values (denoted as "1" in fig. 11) of the first pixel unit 331, similarly, the pixel value in the second intermediate fingerprint image (denoted as "2'" in fig. 11) is obtained by summing and averaging the 2 × 2 original pixel values (denoted as "2" in fig. 11) of the first pixel unit 332, the pixel value in the third intermediate fingerprint image (denoted as "3 '" in fig. 11) is obtained by summing and averaging the 2 × 2 original pixel values (denoted as "3" in fig. 11) of the first pixel unit 333, and the pixel value in the fourth intermediate fingerprint image (denoted as "4'" in fig. 11) is obtained by summing and averaging the 2 × 2 original pixel values (denoted as "4" in fig. 11) of the first pixel unit 334.

After the above physical pixel synthesis, 4 intermediate fingerprint images are formed, and the sum of the pixel value numbers of the 4 intermediate fingerprint images is 1/4 of the original pixel value number in the original image, and the pixel value number of each intermediate fingerprint image is 1/16 of the original pixel value number in the original image.

After physical pixel synthesis, the number of pixel values is greatly reduced, which is beneficial to the processing of subsequent digital images and improves the image processing efficiency.

Optionally, after the physical pixel synthesis, further, digital pixel synthesis may be performed on the 4 intermediate fingerprint images, so as to further reduce the number of pixel values and improve the image processing efficiency.

Alternatively, the process of digital pixel synthesis is not implemented by analog hardware circuits, but may be implemented by digital circuits, for example, the fingerprint identification apparatus may include a processing unit for performing digital pixel synthesis on the first intermediate fingerprint image, the second intermediate fingerprint image, the third intermediate fingerprint image and the fourth intermediate fingerprint image, the processing unit including but not limited to an Image Signal Processor (ISP).

In some embodiments, every Y in the first intermediate fingerprint image is₁×Y₂The pixel values are used for carrying out digital pixel synthesis to form a pixel value in the first fingerprint image; every Y in the second intermediate fingerprint image₁×Y₂The pixel values are used for carrying out digital pixel synthesis to form one pixel value in the second fingerprint image; every Y in the third intermediate fingerprint image₁×Y₂The pixel values are used for carrying out digital pixel synthesis to form a pixel value in the third fingerprint image; every Y in the fourth intermediate fingerprint image₁×Y₂The pixel values are used for carrying out digital pixel synthesis to form a pixel value in the fourth fingerprint image; wherein, Y₁And Y₂Is a positive integer.

Alternatively, Y₁＝Y₂When the fingerprint image is 2, the first fingerprint image, the second fingerprint image, the third fingerprint image and the fourth fingerprint image may be referred to as diagram # 3 in fig. 11.

Where the pixel values in the first fingerprint image (denoted "1" in figure 11) are the 2 x 2 pixel values in the first intermediate fingerprint image (denoted "1 '" in figure 11) after the sum-and-average, similarly, the pixel values in the second fingerprint image (denoted "2" in figure 11) are the 2 x 2 pixel values in the second intermediate fingerprint image (denoted "2'" in figure 11) after the sum-and-average, the pixel values in the third fingerprint image (denoted "3 '" in figure 11) are the 2 x 2 pixel values in the third intermediate fingerprint image (denoted "3'" in figure 11) after the sum-and-average, and the pixel values in the fourth fingerprint image (denoted "4 '" in figure 11) are the 2 x 2 pixel values in the fourth intermediate fingerprint image (denoted "4'" in figure 11) after the sum-and-average.

After the above digital pixel synthesis, 4 fingerprint images for fingerprint identification were formed, and the number of pixel values of each fingerprint image was 1/64 of the number of original pixel values in the original image.

It is understood that the 4 fingerprint images may also be subjected to other subsequent image processing, for example, the 4 fingerprint images are interspersed and reconstructed into one fingerprint image and then used for fingerprint identification, or any one of the 4 fingerprint images may be used for fingerprint identification alone. In the embodiment of the present application, only the pixel synthesis process in the image processing process is listed, and other image processing processes include, but are not limited to, the image processing process in the prior art, which is not described herein.

It should be further understood that, in the above processes of physical pixel synthesis and digital pixel synthesis, an average value of a plurality of pixel values is used as a synthesized pixel value, and in addition to this mode, a maximum value, a minimum value, or a calculated value obtained according to another calculation mode of the plurality of pixel values may be used as the synthesized pixel value, which is not specifically limited in the embodiment of the present application.

Further, as shown in fig. 11, before the 4 intermediate fingerprint images are digitally pixel-combined, the 4 intermediate fingerprint images may be low-pass filtered to reduce the effect of moire, and after the 4 intermediate fingerprint images are low-pass filtered, the digital pixel combining process may be performed, thereby reducing the amount of pixel data and further optimizing the fingerprint image quality.

Optionally, in this embodiment of the present application, the fingerprint identification apparatus 300 may further include a low-pass filter (LPF) for performing the low-pass filtering process.

As shown in the 1# diagram in fig. 11, in the original image, the distance between the pixel values of two adjacent pixel units receiving the light signals in the same direction is L in the X direction and the Y direction, in other words, the spatial sampling period of the fingerprint identification device 300 is L.

Specifically, the spatial sampling period L of the fingerprint identification device 300 may also be understood as an arrangement period of a plurality of fingerprint identification units, or an arrangement period of microlenses in a microlens array formed by a plurality of fingerprint identification units, or an arrangement period of pixel unit groups in a pixel array formed by a plurality of fingerprint identification units.

By X₁×X₂After the physical pixel composition, if X₁＝X₂The spatial sampling period of the fingerprint recognition device 300 is changed from L to X × L. Then passes through Y₁×Y₂After digital pixel synthesis of (2), Y₁＝Y₂The spatial sampling period of the fingerprint recognition device 300 is changed from X × L to Y × X × L.

In some embodiments, L is between 12 μm and 20 μm, e.g., L15 μm, X₁＝X₂＝2，X₁＝X₂The spatial sampling period of the fingerprint identification device 300 is 60 μm, which is between 40 μm and 70 μm, which is the preferred spatial sampling period of the fingerprint.

In addition to the above-mentioned forming of the fingerprint image by performing the physical pixel synthesis, the low-pass filtering and the digital pixel synthesis on the original pixel values in the original image, in another embodiment, only the original pixel values in the original image may be subjected to the physical pixel synthesis or the digital pixel synthesis, for example, only the original pixel values in the original image may be subjected to the physical pixel synthesis of 3 × 3, and if the original spatial sampling period L of the fingerprint recognition device is 15 μm, after the physical pixel synthesis of 3 × 3, the spatial sampling period of the fingerprint recognition device is 45 μm, and then the low-pass filtering and the digital pixel synthesis are not performed again, and in this embodiment, the spatial sampling period of the fingerprint recognition device is also between the spatial sampling periods of 40 μm and 70 μm, and a good fingerprint image can be obtained.

Optionally, in this embodiment of the present application, the spatial sampling period of the fingerprint identification device is related to the spatial imaging period of the display screen, for example, the spatial sampling period of the fingerprint identification device 300 is less than half of the spatial imaging period of the display screen, so that the spatial sampling period of the fingerprint identification device can satisfy the nyquist sampling law with respect to the spatial imaging period of the display screen, that is, moire fringes can be avoided from occurring in the fingerprint image, and accordingly, the fingerprint identification effect is improved.

The spatial imaging period of the display screen may be a period of a pixel unit of the display screen. Or, the spatial imaging period of the display screen may also be a ratio of a pixel unit period of the display screen to a scaling factor K of the optical imaging system, where K is a scaling ratio between an image displayed in a photosensitive area in a pixel unit in the fingerprint identification device and an image collected by the pixel unit in the photosensitive area.

At present, the pixel unit period of the existing high-pixel-density screen in the market, namely the space imaging period of the display screen is mostly more than 45um, and for the screen with dense pixel arrangement, the screen structure period is more complex. Typically the fingerprint module is required to be within a mounting tolerance of, for example, ± 2.5 ° by mounting tolerances so that the period of the moire fringes is outside the fingerprint period. If the spatial sampling period of the fingerprint recognition device is between 25-50um, there may be no proper tolerance angle for the densely arranged pixel screens or a large rotation angle may be required to move the period of the moire fringes away from the fingerprint period. Since the parameters of different screens may be different, the rotation angle of the fingerprint recognition device may be different for different screens, which may not achieve product normalization.

In order to solve the problem, according to the scheme of the embodiment of the application, if the spatial sampling rate period of the fingerprint identification device is smaller than half of the spatial imaging period of the display screen, for example, smaller than 20um, moire fringes can be prevented from appearing in the fingerprint image, and accordingly, the fingerprint identification effect is improved. Meanwhile, the universality of the fingerprint module can be increased, and the moire fringe problem can be solved in the fingerprint image caused by almost all screens on the market without rotation.

As can be seen from the above description, the spatial sampling rate of the fingerprint identification device in the embodiment of the present application is not only dependent on the original spatial sampling rate of the fingerprint identification device, i.e. not only dependent on the arrangement period of the pixel units receiving the same direction, but also dependent on the subsequent pixel synthesis process. The subsequent image processing process and the spatial sampling period of the fingerprint identification device are comprehensively considered, and an optimal implementation scheme is adopted, so that the moire fringe problem in the fingerprint image is solved, the quality of the fingerprint image is improved, and the image processing speed is increased.

The embodiment of the application also provides electronic equipment which can comprise a display screen and the fingerprint identification device, wherein the fingerprint identification device is arranged below the display screen to realize optical fingerprint identification under the screen. The electronic device may be any electronic device having a display screen.

The display screen may be the display screen described above, for example, an OLED display screen or other display screens, and the description of the display screen in the above description may be referred to for the relevant description of the display screen, and for brevity, the description is not repeated here.

In some embodiments of the present application, a layer of foam may be disposed below the display screen, and the layer of foam may be disposed above the fingerprint recognition device with at least one opening for transmitting the light signal reflected by the finger to the fingerprint recognition device.

For example, there is the cotton black bubble of one deck below the display screen, and this black bubble is cotton can be provided with an trompil in fingerprint identification device's top, and when the finger was put in the display screen top of lighting up, the light that the display screen sent will be reflected to the finger, and the reverberation via finger reflection can pierce through the display screen and transmit to fingerprint identification device through at least one trompil. A fingerprint is a diffuse reflector whose reflected light is present in all directions.

Optionally, the display screen displays a green, cyan or white light spot at the finger placement area or the fingerprint detection area, and the fingerprint identification device performs fingerprint identification by using the green, cyan or white light source.

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

In some embodiments of the present application, there may or may not be a gap between the fingerprint recognition device and the display screen.

For example, there may be a gap of 0 to 1mm between the fingerprint recognition device and the display screen.

In some embodiments of the present application, the fingerprint recognition device may output the collected image to a special processor of a computer or a special processor of an electronic device, so as to perform fingerprint recognition.

It should be understood that the processor of the embodiments of the present application may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The processor may be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

It will be appreciated that the fingerprinting of embodiments of the present application may also include memory, which may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile Memory may be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash Memory. The volatile Memory may be a Random Access Memory (RAM) which functions as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static random access memory (Static RAM, SRAM), dynamic random access memory (dynamic RAM, DRAM), Synchronous dynamic random access memory (Synchronous DRAM, SDRAM), Double Data Rate Synchronous dynamic random access memory (DDR SDRAM), Enhanced Synchronous SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), and Direct Rambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. 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.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed 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 can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

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

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A fingerprint identification device, its characterized in that is applicable to the below of display screen in order to realize optical fingerprint identification under the screen, fingerprint identification device includes:

fingerprint identification module, including a plurality of fingerprint identification units, every fingerprint identification unit in a plurality of fingerprint identification units includes:

a microlens;

at least two layers of diaphragm layers, which are arranged below the micro lens, wherein each diaphragm layer of the at least two layers of diaphragm layers is provided with a light through hole to form a plurality of light guide channels in different directions, in the at least two layers of diaphragm layers, the non-light through hole area of at least one first diaphragm layer is used for absorbing visible light, and the non-light through hole area of at least one second diaphragm layer is used for transmitting non-pixel sensitive light and absorbing pixel sensitive light;

the pixel units are arranged below the at least two layers of diaphragm layers, the pixel units are correspondingly arranged at the bottoms of the light guide channels one by one, the responsivity of the pixel units to the non-pixel sensitive light is smaller than or equal to a first preset threshold, the responsivity of the pixel units to the pixel sensitive light is larger than or equal to a second preset threshold, and the first preset threshold is smaller than the second preset threshold;

the fingerprint light signals returned after being reflected or scattered by the finger above the display screen are converged by the micro lens, wherein a plurality of target fingerprint light signals in different directions are transmitted to the plurality of pixel units through the plurality of light guide channels respectively, and the plurality of target fingerprint light signals are used for detecting fingerprint information of the finger.

2. The fingerprint identification device of claim 1, wherein the non-through aperture region of the first aperture layer is further configured to transmit infrared light, and the non-through aperture region of the first aperture layer is a visible light cut-off filter layer for transmitting infrared light.

3. The fingerprint recognition device according to claim 2, further comprising:

and the infrared cut-off filter is arranged in a light path from the display screen to the plurality of pixel units in the fingerprint identification module.

4. The fingerprint recognition device according to claim 3, wherein the infrared cut filter is disposed above the fingerprint recognition module.

5. The fingerprint recognition device of claim 1, wherein the non-pixel sensitive light is a first color light, the pixel sensitive light comprises a second color light, and the non-clear aperture region in the second aperture layer is configured to transmit the first color light and absorb the second color light.

6. The fingerprint recognition device according to claim 5, wherein the first color light is blue light, and the non-through aperture region of the second diaphragm layer is a filter layer formed of a blue filter material or a filter layer formed of a violet filter material.

7. The fingerprint recognition device according to claim 5, wherein the display screen is configured to emit the second color light in the finger pressing area, and the second color light is reflected or scattered from the finger and then is converged by the micro lens, wherein a plurality of second color target fingerprint light signals in different directions are transmitted to the plurality of pixel units through the plurality of light guide channels, respectively, and the plurality of second color target fingerprint light signals are used for detecting fingerprint information of the finger.

8. The fingerprint recognition device of claim 7, wherein the second color light is green or cyan.

9. The fingerprint recognition device according to any one of claims 1 to 8, wherein the first preset threshold is 10% or less, and the second preset threshold is 70% or more.

10. The fingerprint recognition device according to any one of claims 1 to 8, wherein an absorbance of the non-clear aperture region of the at least one second diaphragm layer sensitive to the pixels is greater than a third preset threshold.

11. The fingerprint recognition device according to claim 10, wherein the third predetermined threshold is equal to or greater than 70%.

12. The fingerprint recognition device according to any one of claims 1 to 8, wherein the at least two layers of diaphragm layers are three layers of diaphragm layers, a middle layer of diaphragm layers of the three layers of diaphragm layers is the first diaphragm layer, and a top layer of diaphragm layers and a bottom layer of diaphragm layers of the three layers of diaphragm layers are the second diaphragm layer.

13. The fingerprint identification device according to claim 12, wherein a plurality of light passing holes corresponding to the plurality of pixel units in a one-to-one manner are provided in an intermediate diaphragm layer of the three diaphragm layers to form the plurality of light guide channels.

14. The fingerprint identification device according to claim 13, wherein a top diaphragm layer of the three diaphragm layers has a light hole, and a bottom diaphragm layer of the three diaphragm layers has a plurality of light holes corresponding to the plurality of pixel units one to one, respectively, to form the plurality of light guide channels.

15. The fingerprint recognition device of claim 12, wherein the plurality of pixel units are formed in a sensor chip, an optical path height between a lower surface of the micro lens and an upper surface of the sensor chip is H,

the distance between the bottom diaphragm layer in the three diaphragm layers and the upper surface of the sensor chip is between 0 and H/3, the distance between the middle diaphragm layer in the three diaphragm layers and the upper surface of the sensor chip is between H/5 and 2H/3, and the distance between the top diaphragm layer in the at least two diaphragm layers and the upper surface of the sensor chip is between H/2 and H.

16. The fingerprint recognition device according to any one of claims 1 to 8, wherein the at least two diaphragm layers are two diaphragm layers, a bottom diaphragm layer of the two diaphragm layers is the first diaphragm layer, and a top diaphragm layer of the two diaphragm layers is the second diaphragm layer.

17. The fingerprint identification device according to claim 16, wherein a plurality of light passing holes corresponding to the plurality of pixel units in a one-to-one manner are disposed in a bottom diaphragm layer of the two diaphragm layers to form the plurality of light guide channels.

18. The fingerprint recognition device of claim 17, wherein a light passing hole is formed in a top diaphragm layer of the two diaphragm layers to form the plurality of light guide channels.

19. The fingerprint recognition device of claim 16, wherein the plurality of pixel units are formed in a sensor chip, an optical path height between a lower surface of the micro lens and an upper surface of the sensor chip is H,

the distance between the bottom diaphragm layer of the at least two diaphragm layers and the upper surface of the sensor chip is H/5-2H/3, and the distance between the top diaphragm layer of the at least two diaphragm layers and the upper surface of the sensor chip is H/2-H.

20. The fingerprint identification device according to any one of claims 1 to 8, wherein the light passing holes in the plurality of light guide channels decrease in aperture from top to bottom in sequence.

21. The fingerprint recognition device of claim 20, wherein the plurality of pixel units are formed in a sensor chip, the micro-lens has a diameter D, an optical path height between a lower surface of the micro-lens and an upper surface of the sensor chip is H, an optical path height between one of the at least two diaphragm layers and the upper surface of the sensor chip is H, and an aperture diameter D of a light-passing hole in the one diaphragm layer is in a range of (1 ± 0.3) × D × H/H.

22. The fingerprint recognition device according to any one of claims 1 to 8, further comprising:

the light guide device comprises a metal circuit layer, a light guide channel and a light source, wherein a plurality of light through holes are formed in the metal circuit layer, and are arranged above a plurality of pixel units in a one-to-one correspondence manner and below a plurality of light guide channels in a one-to-one correspondence manner;

23. The fingerprint identification device of claim 22, wherein the center of the light through hole in a first light guide channel of the plurality of light guide channels is located on a first straight line, and the light through hole in the metal circuit layer corresponding to the first light guide channel is also located on the first straight line.

24. The fingerprint identification device of claim 22, wherein the light holes in the at least two diaphragm layers and the light holes in the metal circuit layer are circular light holes.

25. The fingerprint recognition device of claim 24, wherein the diameter of the light passing holes in the metal trace layer is smaller than the diameter of the light passing holes in the bottom layer of the at least two layers of diaphragm layers.

26. The fingerprint recognition device according to any one of claims 1 to 8, wherein each fingerprint recognition unit further comprises:

and the transparent medium layer is used for connecting the at least two diaphragm layers.

27. The fingerprint recognition device of claim 26, wherein each fingerprint recognition unit further comprises:

the first buffer layer is used for connecting the micro lens with the top diaphragm layer of the at least two diaphragm layers;

and the second buffer layer is used for connecting the sensor chip with the bottom diaphragm layer in the at least two diaphragm layers.

28. The fingerprint recognition device of claim 27, wherein the difference between the refractive indices of the transparent medium layer and the first buffer layer, and the difference between the refractive indices of the transparent medium layer and the second buffer layer are within a predetermined threshold.

29. The fingerprint recognition device according to any one of claims 1 to 8, wherein the plurality of pixel units are four pixel units, the four pixel units form a pixel area of a quadrilateral area, and a center point of the pixel area coincides with or does not coincide with a center of the microlens in a vertical direction.

30. The fingerprint recognition device of claim 29, wherein the plurality of light-conducting channels are four light-conducting channels, and at least three of the four light-conducting channels are oriented in a direction that is oblique with respect to the display screen.

31. The fingerprint recognition device of claim 30, wherein the four light-guiding channels are angled between 10 and 45 ° from a direction perpendicular to the display screen.

32. The fingerprint recognition device of claim 29, wherein each of the four pixel units comprises four photosensitive areas, and the four photosensitive areas are located at the bottom of the four light guide channels.

33. The fingerprint recognition device of claim 32, wherein at least one of the four photosensitive regions is disposed off-center from a center of the pixel cell in which it is disposed.

34. The fingerprint recognition device of claim 33, wherein the at least one photosensitive area is offset in a direction away from a center of the microlens.

35. The fingerprint recognition device of claim 34, wherein the four pixel units form a quadrilateral pixel area, and the four photosensitive areas are respectively located at four corners of the pixel area.

36. The apparatus according to claim 29, wherein the fingerprint recognition module comprises a plurality of sets of the four pixel units;

the optical signals received by a plurality of first pixel units in the plurality of groups of four pixel units are used for forming a first fingerprint image of the finger, the optical signals received by a plurality of second pixel units in the plurality of groups of four pixel units are used for forming a second fingerprint image of the finger, the optical signals received by a plurality of third pixel units in the plurality of groups of four pixel units are used for forming a third fingerprint image of the finger, the optical signals received by a plurality of fourth pixel units in the plurality of groups of four pixel units are used for forming a fourth fingerprint image of the finger, and one or more images of the first fingerprint image, the second fingerprint image, the third fingerprint image and the fourth fingerprint image are used for fingerprint identification.

37. The fingerprint recognition device of claim 36, wherein each X of the plurality of first pixel units₁×X₂The first pixel units are connected to the first summing and averaging circuit to perform physical pixel synthesis to form a pixel value in the first intermediate fingerprint image;

every X in the plurality of second pixel units₁×X₂The second pixel units are connected to the second summing and averaging circuit to perform physical pixel synthesis to form a pixel value in the second intermediate fingerprint image;

every X in the plurality of third pixel units₁×X₂The third pixel units are connected to the third summing and averaging circuit to perform physical pixel synthesis to form a pixel value in the third intermediate fingerprint image;

every X in the plurality of fourth pixel units₁×X₂The fourth pixel units are connected to the fourth summing and averaging circuit to perform physical pixel synthesis to form a pixel value in the fourth intermediate fingerprint image; wherein, X₁And X₂Is a positive integer.

38. The fingerprint recognition device of claim 37, further comprising:

the first summing and averaging circuit, the second summing and averaging circuit, the third summing and averaging circuit, and the fourth summing and averaging circuit.

39. The fingerprint recognition device of claim 37, wherein the fingerprint recognition device is a portable fingerprint recognition deviceEvery Y in the first intermediate fingerprint image₁×Y₂The pixel values are used for carrying out digital pixel synthesis to form a pixel value in the first fingerprint image;

every Y in the second intermediate fingerprint image₁×Y₂The pixel values are used for carrying out digital pixel synthesis to form one pixel value in the second fingerprint image;

every Y in the third intermediate fingerprint image₁×Y₂The pixel values are used for carrying out digital pixel synthesis to form one pixel value in the third fingerprint image;

every Y in the fourth intermediate fingerprint image₁×Y₂The pixel values are used for carrying out digital pixel synthesis to form one pixel value in the fourth fingerprint image; wherein, Y₁And Y₂Is a positive integer.

40. The fingerprint recognition device of claim 39, further comprising:

a processing unit for performing digital pixel synthesis on the first intermediate fingerprint image, the second intermediate fingerprint image, the third intermediate fingerprint image and the fourth intermediate fingerprint image.

41. The fingerprint recognition device of claim 39, wherein the first intermediate fingerprint image, the second intermediate fingerprint image, the third intermediate fingerprint image and the fourth intermediate fingerprint image are configured to be low pass filtered and then digitally pixel synthesized.

42. The fingerprint recognition device of claim 41, further comprising:

a low pass filter for low pass filtering the first intermediate fingerprint image, the second intermediate fingerprint image, the third intermediate fingerprint image and the fourth intermediate fingerprint image.

43. The fingerprint recognition device of claim 39, wherein X is₁＝X₂＝Y₁＝Y₂＝2。

44. The apparatus of claim 36, wherein the first pixel units are not adjacent to each other, the second pixel units are not adjacent to each other, the third pixel units are not adjacent to each other, and the fourth pixel units are not adjacent to each other.

45. The fingerprint recognition device according to any one of claims 1 to 8, wherein the arrangement period of the light-emitting pixels in the display screen is P₁Spatial sampling period P of the fingerprint recognition device₂＜P₁/2。

46. The apparatus according to claim 45, wherein the spatial sampling period of the fingerprint recognition apparatus is calculated according to the arrangement period of the fingerprint recognition units and the pixel synthesis method.

47. The fingerprint recognition device according to any one of claims 1 to 8, wherein the arrangement period of the plurality of fingerprint recognition units is between 12 μm and 20 μm.

48. The fingerprint recognition device according to any one of claims 1 to 8, wherein the optical path thickness of each fingerprint recognition unit of the plurality of fingerprint recognition units is within 30 μm.

49. The fingerprint recognition device of any one of claims 1-8, wherein the distance between the fingerprint recognition device and the display screen is 0-1 mm.

50. An electronic device, comprising: a display screen; and

the fingerprint recognition device of any one of claims 1-49, said fingerprint recognition device disposed below said display screen to enable off-screen optical fingerprint recognition.

51. The electronic device of claim 50, wherein the display screen is configured to display a green, cyan or white light spot in a fingerprint detection area, and the fingerprint identification device is configured to receive a green, cyan or white target fingerprint light signal to detect fingerprint information of a finger.