CN112069942A

CN112069942A - Optical detection system and electronic equipment under screen

Info

Publication number: CN112069942A
Application number: CN202010859937.XA
Authority: CN
Inventors: 徐洪伟; 张东虎
Original assignee: Shenzhen Fushi Technology Co Ltd
Current assignee: Shenzhen Fushi Technology Co Ltd
Priority date: 2020-08-24
Filing date: 2020-08-24
Publication date: 2020-12-11
Anticipated expiration: 2040-08-24
Also published as: CN112069942B

Abstract

The application discloses an optical detection device for optically detecting an external object. The optical detection device includes: at least one first light detection unit including a first pixel unit that detects a color change of light returned through the external object by the first pixel unit; and a plurality of second light detection units, each of which includes a second pixel unit, the second light detection units receiving light returned through the external object through the second pixel units to acquire image information of the external object. The application also discloses an optical detection system and electronic equipment under the screen comprising the optical detection device.

Description

Optical detection system and electronic equipment under screen

Technical Field

The present application relates to the field of optoelectronic technologies, and in particular, to an off-screen optical detection system and an electronic device using an optical principle to detect an external object.

Background

At present, the optical fingerprint recognition function of electronic products such as mobile phones and tablet computers is usually realized by recognizing a fingerprint image of a finger pressed on a screen by a user, and the optical fingerprint recognition function is easily broken by lawless persons using fake fingerprint rubber heads, printed fingerprint images and other fake fingerprint channels. Therefore, the optical fingerprint identification function of the existing electronic product has obvious potential safety hazard.

Disclosure of Invention

In view of the above, the present invention provides an off-screen optical detection system and an electronic device capable of improving the problems of the prior art.

One aspect of the present application provides an optical detection system under a screen for detecting a finger of a user, comprising:

a protective layer;

the display screen is positioned below the protective layer and used for displaying pictures;

an optical detection device located below the display screen to receive light returned by the finger through the display screen and the protective layer, the optical detection device comprising:

at least one first light detection unit including a first pixel unit that detects a color change of light returned through the external object by the first pixel unit; and

a plurality of second light detection units, each of which includes a second pixel unit, the second light detection units receiving light returned through the external object through the second pixel unit to acquire image information of the external object;

the control module is used for controlling the first light detection module to respectively detect the colors of the light rays returning through the finger at least two different moments; and

and the processing module is used for comparing the color difference values of the light rays returned by the finger and detected by the first light detection unit at different moments, and judging that the finger is a real finger when the color difference values are larger than a preset color difference threshold value.

In some embodiments, the first light detecting unit includes a first filtering unit disposed on a light incident side of the first pixel unit, and the first filtering unit is configured to transmit light within a predetermined wavelength range to the first pixel unit.

In some embodiments, the predetermined wavelength range of the light transmitted by the first filtering unit is 600nm to 780nm, 490nm to 580nm, or 430nm to 450 nm.

In some embodiments, each of the second light detection units includes a second filter unit disposed on the light incident side of the second pixel unit, and the second filter unit is configured to transmit light in a predetermined wavelength range to the second pixel unit.

In some embodiments, the predetermined wavelength range of the light transmitted by the second filtering unit is 900nm to 1200nm, 390nm to 620nm, or 360nm to 800 nm.

In some embodiments, the first and second light detection units are arranged in an array to form an array of light detection units, wherein two of the first light detection units are disposed adjacent to each other; alternatively, the second light detection unit is provided between the two first light detection units.

In some embodiments, a plurality of the first light detecting units are included, and the first light detecting units are regularly arranged in a preset pattern in the light detecting unit array; alternatively, the first photodetecting units are irregularly arranged in the photodetecting unit array.

In some embodiments, the display device further includes a microlens array disposed above the first pixel unit and the second pixel unit, the microlens array including a plurality of microlenses for converging light returned by the external object to the first pixel unit or the second pixel unit.

In some embodiments, each of the microlenses is disposed corresponding to one of the first pixel units or one of the second pixel units, respectively;

alternatively, each of the microlenses may be provided corresponding to two or more of the first pixel units or two or more of the second pixel units.

In some embodiments, the display device further comprises at least one light blocking layer disposed between the microlens array and the first pixel unit and the second pixel unit, wherein each light blocking layer is formed with an aperture array, and light rays converged by the microlenses are transmitted to the first pixel unit or the second pixel unit through apertures in the aperture array.

In some embodiments, the first light detection unit detects a change in color by detecting a gray level of an image of a portion of the return light having a predetermined wavelength range, the control module controls the first light detection unit to respectively acquire at least two images of the portion of the return light having the predetermined wavelength range at different times, and the processing module compares gray level differences of the at least two images acquired by the first light detection unit to obtain the color difference.

In some embodiments, the display screen includes a touch sensor, the touch sensor is configured to send out a trigger signal to activate the first light detection unit when detecting that the finger touches the surface of the display screen, the time when the first light detection unit starts detecting is defined as a starting point of a first time period, and the control module controls the first light detection unit to detect the color of light returning through the finger at least once in the first time period according to the trigger signal.

In some embodiments, the first time period is less than or equal to 100ms, 200ms, 300ms or 400ms, and the processing module compares the color difference values of the return light from the finger detected by the first light detection unit at least two different times within the first time period to determine whether the finger is a real finger.

In some embodiments, the control module controls the second light detection unit to acquire fingerprint image information of the finger in a second time period after the finger is determined as a real finger, so as to perform fingerprint identification detection on the finger.

In some embodiments, the control module controls the second light detection unit to acquire fingerprint image information of the finger in a second time period after the first time period to perform fingerprint recognition on the finger, the control module controls the first light detection unit to detect the color of the return light of the finger at least once in a third time period after the second time period, the processing module compares the color difference values of the return light of the finger detected by the first light detection unit in the first time period and the third time period respectively to determine whether the finger is a real finger, and the first time period and the third time period are less than or equal to 10ms, 20ms, 30ms or 40ms,

in some embodiments, the control module controls the first light detection unit to detect the color of the return light via the finger and simultaneously activates the second light detection unit to start acquiring fingerprint image information of the finger for fingerprint recognition detection according to a trigger signal.

In some embodiments, the display screen is an active light-emitting display screen, and the light returned by the finger received by the optical detection device is return light generated by the finger under irradiation of visible light rays emitted by the display screen.

In some embodiments, the display screen is an inactive light-emitting display screen, the optical detection system further includes a first detection light source and a second detection light source, the first detection light source is configured to emit a first detection light to the finger, the second detection light source is configured to emit a second detection light to the finger, the first light detection unit detects a color change of the first detection light returned by the finger, and the second light detection unit receives the second detection light returned by the finger to obtain fingerprint image information of the finger for fingerprint identification.

One aspect of the present application provides an electronic device including an underscreen optical detection system as provided in the above embodiments.

The beneficial effect of this application lies in, optical detection system under screen of this application acquires the finger colour difference value that detects respectively at different time quantums through the comparison to judge whether the finger that detects is real finger, can prevent effectively that lawless persons from utilizing artificial finger of imitation right optical detection system's recognition function attacks under the screen, has improved electronic equipment's security.

Drawings

Fig. 1 is a schematic structural diagram of an optical detection system under a screen applied to an electronic device according to an embodiment of the present application;

FIG. 2 is a schematic partial cross-sectional view of the underscreen optical detection system of FIG. 1 taken along line II-II;

fig. 3 is a schematic layout diagram of a pixel unit array on an image sensor according to an embodiment of the present disclosure;

fig. 4 is a schematic layout diagram of a pixel unit array on an image sensor according to another embodiment of the present disclosure;

fig. 5 is a schematic layout diagram of a pixel unit array on an image sensor according to another embodiment of the present disclosure;

fig. 6 is a schematic layout diagram of a pixel unit array on an image sensor according to another embodiment of the present disclosure;

fig. 7 is a schematic layout diagram of a pixel unit array on an image sensor according to another embodiment of the present disclosure;

fig. 8 is a functional module schematic diagram of an electronic device according to an embodiment of the present application.

Fig. 9 is a functional module schematic diagram of an electronic device according to another embodiment of the present application.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

In the detailed description of the embodiments herein, it will be understood that when a substrate, a sheet, a layer, or a pattern is referred to as being "on" or "under" another substrate, another sheet, another layer, or another pattern, it can be "directly" or "indirectly" on the other substrate, the other sheet, the other layer, or the other pattern, or one or more intervening layers may also be present. The thickness and size of each layer in the drawings of the specification may be exaggerated, omitted, or schematically represented for clarity. Further, the sizes of the elements in the drawings do not completely reflect actual sizes.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The following disclosure provides many different embodiments, or examples, for implementing different features of the application. To simplify the disclosure of the present application, the components and settings of a specific example are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or reference letters in the various examples, which have been repeated for purposes of simplicity and clarity and do not in themselves dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the application. One skilled in the relevant art will recognize, however, that the subject matter can be practiced without one or more of the specific details, or with other structures, components, and so forth. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring the application.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an off-screen optical detection system 10 applied to an electronic device 1 according to an embodiment of the present disclosure. The electronic device 1 comprises an off-screen optical detection system 10 for optically detecting the external object 2. The underscreen optical inspection system 10 includes a protective layer 12, a display screen 14, and an optical inspection device 16 located below the display screen 14. The display screen 14 is located below the protective layer 12 and is used for displaying pictures. The protective layer 12 is transparent to display light from the display screen 14 and protects the display screen 14 from damage.

Optionally, in some embodiments, the protective layer 12 may comprise a transparent material, such as, but not limited to, transparent glass, transparent polymer, any other transparent material, and the like. The protective layer 12 may have a single-layer structure or a multi-layer structure. The protective layer 12 is a substantially thin plate having a predetermined length, width and thickness. It will be appreciated that the protective layer 12 may comprise a plastic film, a toughened film, or other film layer or the like to which the user is attached in actual use. The outer surface 120 of the protective layer 12 may be the outermost surface of the electronic device 1. Upon detection, the external object 2 may directly contact the outer surface 120 of the protective layer 12.

Alternatively, in some embodiments, the display screen 14 may be an active light emitting display screen, such as but not limited to an Organic Light Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. Alternatively, in other embodiments, the display 14 may be a passive light-emitting display, such as but not limited to a Liquid Crystal Display (LCD) or an electronic paper display.

The optical detection device 16 is used for receiving the light returned by the external object 2 through the protective layer 12 and the display screen 14, and converting the received light into a corresponding electric signal to perform corresponding information detection. The external object 2 is, for example, a finger of a user, and the optical detection device 16 is, for example, used for performing detection of biometric information, such as, but not limited to, fingerprint information, palm print information, and other texture information, and/or blood oxygen information, heartbeat information, pulse information, and other living body information, but the application is not limited thereto. It will be understood that the light returning via the external object 2 includes, but is not limited to, detection light returning by reflection from the surface of the external object 2 and detection light or other light returning by transmission from the interior of the external object 2 through the surface.

In the present application, the optical detection device 16 performs the finger authentication detection and the fingerprint recognition detection by taking the external object 2 as the user's finger. Because the inside of a real finger of a human contains flowing blood, the finger tip is uniformly filled with the blood in the finger under the natural state that the finger is not stressed, so that the finger tip is light red. When the finger 2 presses the display screen 14, the part of the finger 2 in contact with the display screen 14 is obviously yellowed due to blood flowing away caused by stress, so that the color of the part of the finger 2 in contact with the display screen 14 is obviously changed from light red to light yellow in the process that the finger 2 is just in contact with the display screen 14 and the finger 2 fully presses the display screen 14. However, the material (e.g., rigid plastic material or flat paper material) used to forge the finger 2 does not exhibit any significant color change on its surface during the pressing process. Therefore, the authenticity of the finger 2 can be effectively discriminated by detecting the color change of the finger 2 during the pressing of the display screen 14.

The electronic device 1 may be, for example, but not limited to, a consumer electronic product, a home electronic product, a vehicle-mounted electronic product, a financial terminal product, or other suitable type of electronic product. The consumer electronic products include, for example, mobile phones, tablet computers, notebook computers, desktop monitors, all-in-one computers, and the like. Household electronic products are, for example, smart door locks, televisions, refrigerators and the like. The vehicle-mounted electronic product is, for example, a vehicle-mounted navigator, a vehicle-mounted touch interactive device, and the like. The financial terminal products are ATM machines, terminals for self-service business and the like.

As shown in FIG. 2, FIG. 2 is a schematic partial cross-sectional view of the underscreen optical inspection system 10 shown in FIG. 1 taken along line II-II. Optionally, in some embodiments, the optical detection device 16 includes an optical component 160 and an image sensor 162. The optical assembly 160 converges the light returned through the external object 2 on the image sensor 162 to image the external object 2. The image sensor 162 is used to convert the external object 2 image formed by the optical assembly 160 into a corresponding electrical signal as image data for subsequent storage, transmission and processing analysis. For example, but not limited to, the external object 2 may be a user's finger, and the image of the external object 2 may be a fingerprint image.

The image sensor 162 includes a plurality of pixel units 161, and a readout circuit (not shown) and other auxiliary circuits (not shown) electrically connected to the pixel units 161. The pixel element 161 is a photodetector (photo detector), such as but not limited to a photodiode. The pixel units 161 are arranged in an array to receive the light collected by the optical assembly 160 and convert the light into corresponding electrical signals. The plurality of pixel units of the image sensor 162 and the readout circuit and other auxiliary circuits thereof may be fabricated on one chip (Die) by a semiconductor process to form one optical imaging chip or image sensing chip. Optionally, the area size of a single pixel unit ranges from 5 micrometers (μm) by 5 μm to 10 μm by 10 μm, for example.

The pixel unit 161 includes at least one first pixel unit 1611 and a plurality of second pixel units 1612. The first pixel unit 1611 is configured to detect a color change of the light returned by the finger 2, so as to determine whether the finger 2 is authentic. The second pixel unit 1612 is configured to receive the light returned by the finger 2 to obtain fingerprint image information of the finger 2 for fingerprint identification.

As shown in fig. 3, the first pixel unit 1611 and the second pixel unit 1612 are arranged in an array to form a pixel unit array 1613. Optionally, in some embodiments, the number of the first pixel units 1611 is two or more, and two first pixel units 1611 may be adjacently disposed. The adjacent arrangement here means that the boundaries of two first pixel units are closely connected, and no other pixel units (such as a second pixel unit) are arranged between the two first pixel units. In the embodiment shown in fig. 3, all the first pixel cells 1611 are arranged adjacent to each other in sequence, and one first pixel cell group 1615 is formed in the pixel cell array 1613 to detect a color change of light returning through the finger 2.

Optionally, in other embodiments, the second pixel unit 1612 may also be spaced between two first pixel units 1611. For example, as shown in fig. 4, a predetermined number of some of the first pixel cells 1611 are sequentially disposed adjacent to each other to form a plurality of the first pixel cell groups 1615, and two first pixel cell groups 1615 are spaced apart from each other by the second pixel cell 1612.

In other embodiments, as shown in fig. 5, the number of the first pixel units 1611 is two or more. Any two of the first pixel cells 1611 are spaced apart by the second pixel cell 1612.

In the embodiment shown in fig. 3 to 5, the first pixel cells 1612 or the first pixel cell groups 1615 are regularly arranged according to a predetermined pattern. The regular arrangement means that the arrangement position of the first pixel cell 1612 or the first pixel cell group 1615 is reproduced repeatedly on a regular basis, such as: the first pixel cells 1611 are arranged one at every predetermined number of second pixel cells 1612 along a first direction in the pixel cell array 1613, and arranged one at every predetermined number of second pixel cells 1612 along a second direction. As shown in fig. 6 and 7, in other embodiments, the first pixel unit 1611 or the first pixel unit group 1615 may be arranged in the pixel unit array 1613 in an irregular manner.

It will be appreciated that it is only necessary to ensure that the first pixel element 1611 on the image sensor 162 is capable of generating a detection signal of sufficient intensity for subsequent computational processing. As to the specific number of the first pixel units 1611 and the arrangement manner thereof on the pixel unit array 1613, the present application is not particularly limited.

It should be noted that fig. 3 to fig. 7 are only used to exemplarily illustrate the arrangement of the first pixel unit 1611 and the second pixel unit 1612, and should not be considered as limiting the specific number of the first pixel unit 1611 and the second pixel unit 1612 in the present application.

Referring to fig. 2 to 7, the optical detection device 16 has a predetermined detection range, that is, the optical detection device 16 can effectively detect the spatial range of the external object 2. For example, in some embodiments, the external object 2 is a user's finger, and the optical detection device 16 acquires a fingerprint image of the finger 2 by optical detection principles. Correspondingly, the detection range of the optical detection device 16 is a field of View (FOV) range of the optical imaging system formed by the optical assembly 160 and the image sensor 162. It will be appreciated that the detection area 122 is located within the field angle range of the optical detection device 16, so that the optical detection device 16 can acquire the fingerprint pattern of the portion of the user's finger 2 in contact with the detection area 122.

When detecting, a user presses a finger 2 on a preset detection area 122 on the outer surface 120 of the protective layer 12, light returning through the finger 2 passes through the optical assembly 160 to form a fingerprint image on the pixel unit array 1613, and the second pixel unit 1612 converts the formed fingerprint image into a corresponding electrical signal, that is, the fingerprint image information. Since the first pixel unit 1611 is used to detect the color change of the light returning through the finger 2, the detection signal generated by it cannot be directly used as fingerprint image information of the location. Alternatively, in some embodiments, the fingerprint image information generated by a plurality of second pixel units 1612 adjacent to the first pixel unit 1611 may be used to recover the fingerprint image information of the position of the first pixel unit 1611 by interpolation, fitting, or the like. Alternatively, in some other embodiments, the electrical signal generated when the first pixel unit 1611 detects a color change may be calibrated to the fingerprint image information of the location according to a preset calculation relation.

The optical assembly 160 may include one or more optical elements that enable imaging of the finger 2 or facilitate improved imaging quality. For example, the optical assembly 160 includes, but is not limited to, a filtering unit, an optical modulation element, an optical path guiding structure, and other optical elements.

Optionally, in some embodiments, the optical assembly 160 includes a first filtering unit 1641 and a second filtering unit 1642. The first filtering unit 1641 is disposed on a light incident side of the first pixel unit 1611, and the first filtering unit 1641 is configured to transmit light in a predetermined wavelength range to the corresponding first pixel unit 1611. Alternatively, the first pixel unit 1611 detects the change in the color of the finger 2 by detecting the gray level of the image of the portion of the return light having the preset wavelength range through the finger 2. Specifically, the finger 2 shows a transition from light red to light yellow during the pressing process, and the ratio between the red light component, the green light component and the blue light component of the light returning through the finger 2 changes significantly during the pressing process, so that by detecting the change of the gray level value of the image formed on the first pixel unit 1611 by one of the red light component, the green light component, the blue light component and the combination thereof in the light returning through the finger 2, the corresponding color change of the finger 2 during the pressing process can be obtained. The above method can be implemented by the first filter 1641 cooperating with the first pixel 1611, and the predetermined wavelength range of the light transmitted by the first filter 1641 can be 600nm to 780nm for red light, 490nm to 580nm for green light, or 430nm to 450nm for blue light.

The first filtering unit 1641 is disposed corresponding to the first pixel unit 1611, so the first filtering unit 1641 has the same arrangement as the first pixel unit 1611. For example: the two first filtering units 1641 may be adjacently disposed, and the second filtering unit 1642 may also be spaced; the first filtering unit 1641 may be regularly arranged according to a preset pattern, or irregularly arranged.

Optionally, in some embodiments, the preset wavelength ranges of the light transmitted by all of the first filtering units 1641 may be the same, for example: transmits red, green, blue or other color light. Optionally, in other embodiments, the two first filtering units 1641 may also respectively transmit light beams with different preset wavelength ranges, for example: any two of red light, green light, blue light, and light of other colors are transmitted, respectively. Optionally, in other embodiments, three of the first filtering units 1641 may also transmit light beams with different preset wavelength ranges, for example: any three of red, green, blue, and other colors of light are transmitted, respectively.

The second filtering unit 1642 is used in cooperation with the second pixel unit 1612 to obtain fingerprint image information of the finger 2. The wavelength range of the light transmitted by the second filtering unit 1642 needs to be adapted to the wavelength of the detection light for illuminating the finger 2, and the second filtering unit 1642 is configured to reduce interference of stray light with other wavelengths outside the wavelength range of the detection light to fingerprint detection.

Optionally, in some embodiments, the predetermined wavelength range of the light transmitted by the second filtering unit 1642 is 900nm to 1200nm, 390nm to 620nm, or 360nm to 800 nm. For example, in some embodiments, if the display screen 14 is an active light-emitting display screen, and the detection light for illuminating the finger 2 is visible light emitted from the display screen 14, the preset wavelength range of the light transmitted by the second filtering unit 1642 is 360nm to 800nm or 390nm to 620 nm.

Referring to fig. 9, in some other embodiments, if the display 14 is a passive-light-emitting display, the optical detection system 10 further includes a first detection light source 151 and a second detection light source 152. The first detection light source 151 is configured to emit a first detection light to the finger 2, and the first pixel unit 1611 detects a color change of the first detection light returned by the finger 2. The first detection light is visible light, the second detection light source 152 is configured to emit second detection light to the finger 2, and the second pixel unit 1612 receives the second detection light returned by the finger 2 to obtain fingerprint image information of the finger 2. The second detection light is near infrared light. Correspondingly, the predetermined wavelength range of the light transmitted by the second filtering unit 1642 is 900nm to 1200 nm.

Optionally, in some embodiments, the first filtering units 1641 respectively corresponding to different first pixel units 1611 are separately disposed without being connected to each other, so as to be arranged in a first filtering unit array. Similarly, the second filtering units 1642 respectively corresponding to different second pixel units 1612 are separately disposed without being connected to each other, so as to be arranged in a second filtering unit array. The first filter unit array and the second filter unit array may be located in the same layer, or may be located in different layers.

Alternatively, in some other embodiments, the first filtering units 1641 respectively corresponding to the adjacent first pixel units 1611 may be disposed in connection to form a whole piece of first filtering area. Similarly, the second filtering units 1642 respectively corresponding to the adjacent second pixel units 1612 may also be disposed in connection to form an entire sheet of second filtering regions.

Each of the first pixel units 1611 and the corresponding first filter unit 1641 constitute a first light detection unit 1661 to detect a color change of light returning through the finger 2. Each of the second pixel units 1612 and the corresponding second filter units 1642 form a second light detecting unit 1662 to obtain the fingerprint image information of the finger 2. Thus, the first photo detection units 1661 have the same number and arrangement as the first pixel units 1611, the second photo detection units 1662 have the same number and arrangement as the second pixel units 1612, and the first photo detection units 1661 and the second photo detection units 1662 are arranged in an array to form a photo detection unit array. It is understood that in other embodiments, the pixel unit 161 may be a photodetector that only photoelectrically converts light of a predetermined wavelength range, and the corresponding first and

second filtering units

1641 and 1642 of the first and second

light detecting units

1661 and 1662 may also be omitted.

Optionally, in some embodiments, the optical assembly 160 further comprises a microlens array 163. The microlens array 163 is disposed above the first and

second pixel units

1611 and 1612, and the microlens array 163 includes a plurality of microlenses 1630 for converging light returned by the finger 2 to the first or

second pixel unit

1611 or 1612. The plurality of microlenses 1630 can be arranged in an array, wherein each microlens 1630 can be a hemispherical lens or a non-hemispherical lens.

Alternatively, in some embodiments, each of the microlenses 1630 can be disposed corresponding to one of the first pixel cells 1611 or one of the second pixel cells 1612, respectively.

Alternatively, in some other embodiments, each of the microlenses 1630 can also be disposed corresponding to two or more of the first pixel units 1611 or two or more of the second pixel units 1612, respectively.

Optionally, in some embodiments, the optical assembly 160 may further include at least one light blocking layer 165, and the at least one light blocking layer 165 is disposed between the microlens array 163 and the first and

second pixel cells

1611 and 1612. Each light-blocking layer 165 of the at least one light-blocking layer 165 is formed with an aperture array, and light rays converged by the microlens 1630 are transmitted to the first pixel unit 1611 or the second pixel unit 1612 through the apertures 1650 on the aperture array. The light blocking layer 165 may prevent optical crosstalk between adjacent pixel units 161. The at least one light-blocking layer 165 includes a bottom light-blocking layer 165 closest to the pixel cell array 1613, and the small holes 1650 on the bottom light-blocking layer 165 correspond to the first pixel cell 1611 and the second pixel cell 1612 in the pixel cell array 1613 in a one-to-one manner.

Alternatively, in some embodiments, the at least one light blocking layer 165 may include a plurality of light blocking layers. One small hole 1650 in the light-blocking layers 165 of the plurality of light-blocking layers 165 except for the bottom light-blocking layer 165 may correspond to the plurality of first pixel units 1611 or the plurality of second pixel units 1612, that is, light passing through the one small hole 1650 may be finally transmitted to the different plurality of first pixel units 1611 and the different plurality of second pixel units 1612, respectively. Optionally, the apertures 1650 of the light blocking layers 165 corresponding to the same first pixel unit 1611 or second pixel unit 1612 are sequentially reduced in aperture from top to bottom. Alternatively, one or more of the at least one light blocking layer 165 may be a metal wiring layer of the image sensor 162. Alternatively, one of the at least one light blocking layer 165 may be disposed at a back focal plane position of the microlens array 163.

Optionally, in some embodiments, the optical detection device 16 may further include a transparent medium layer 167. The transparent medium layer 167 may be used to connect the microlens array 163, the filter unit array 164, the at least one light blocking layer 165, and/or the pixel unit array 1613.

Optionally, in some embodiments, all or part of the optical assembly 160 may be packaged with the image sensor 162 as an image sensing chip. For example, the optical assembly 160 may be formed on the pixel unit 161 of the image sensor 162 through a semiconductor process and then packaged together with the image sensor 162.

Alternatively, in some other embodiments, all or part of the optical assembly 160 may not be packaged with the image sensor 162, but may be disposed outside the image sensor 162. For example, the optical assembly 160 is attached to a light-sensing surface of the image sensor 162, or is suspended above the image sensor 162 by a support structure such as a lens barrel.

Referring to fig. 2 and 8, the optical detection system 10 further includes a control module 17. The control module 17 is used for controlling the first light detecting unit 1661 to perform the authenticity detection of the finger 2 and for controlling the second light detecting unit 1662 to perform the fingerprint identification detection. Optionally, in some embodiments, the display screen 14 is an active light-emitting display screen, and the display screen 14 further includes a touch sensor (not shown) configured to send a trigger signal when the finger 2 is detected to touch the detection area 122 of the display screen 14. The control module 17 is connected to the display screen 14 and the optical detection device 16. The control module 17 controls the display pixels 140 in the detection area 122 of the display 14 to emit visible light as detection light to illuminate the finger 2 according to the trigger signal, and controls the first light detection unit 1661 to start detection. If the moment when the first light detection unit 1661 starts detecting is defined as the starting point of a first time period, the first light detection unit 1661 detects the color of light returning through the finger 2 at least once in the first time period.

Alternatively, in some embodiments, the finger 2 may be first detected for authenticity, and then the fingerprint detection may be performed after the finger 2 is determined to be a true finger, so as to avoid the optical detection device 16 consuming power to perform fingerprint identification on a fake finger. In this case, the control module 17 controls the first light detection unit 1661 to detect the color of the light returned by the finger 2 at least two different times within the first time period, respectively, so as to determine the authenticity of the finger 2 by comparing the color difference of the finger 2 at the different times. To ensure that the finger 2 is able to change color upon completion of sufficient depression within a first period of time, which is relatively long, e.g., less than or equal to 100ms, 200ms, 300ms, or 400ms, while the first light detection unit 1661 is able to perform a sufficient number of color detections. The control module 17 controls the second light detection unit 1662 to acquire fingerprint image information of the finger 2 in a second time period after the finger 2 is determined to be a real finger, so as to perform fingerprint identification detection on the finger 2.

Optionally, in other embodiments, the finger 2 authenticity detection and the fingerprint identification detection may be performed alternately to improve the overall efficiency of fingerprint identification. In this case, the control module 17 controls the first light detection unit 1661 to detect the color of the light returned via the finger 2 at least once in the first period of time. The control module 17 controls the second light detecting unit 1662 to acquire the fingerprint image information of the finger 2 in a second time period after the first time period, so as to perform fingerprint identification on the finger 2. The control module 17 controls the first light detecting unit 1661 to detect the color of the light returned by the finger 2 at least once in a third time period after the second time period, so as to determine the authenticity of the finger 2 by comparing the color difference of the finger 2 detected in the first time period and the third time period. The first and second time periods may be relatively short, such as less than or equal to 10ms, 20ms, 30ms, or 40 ms.

Optionally, in other embodiments, the authenticity detection and the fingerprint identification detection of the finger 2 may be performed simultaneously, so as to further improve the overall efficiency of fingerprint identification. In this case, the control module 17 controls the first light detection unit 1661 and the second light detection unit 1662 to perform the corresponding finger 2 authenticity detection and fingerprint identification detection simultaneously according to the trigger signal of the touch sensor. Since the time required for the first light detection unit 1661 to detect the color of light returning once through the finger 2 is much shorter than the time required for the second light detection unit 1662 to acquire fingerprint image information once, the first light detection unit 1661 has sufficient time to perform a plurality of times of detection of the color of the finger 2 in the process of acquiring fingerprint image information of the finger 2 by the second light detection unit 1662. Meanwhile, the color detection and the fingerprint recognition detection of the finger 2 may respectively use portions having different wavelength ranges in the light returning through the finger 2, thereby preventing the two detections from interfering with each other when performed simultaneously.

In other embodiments, as shown in FIG. 9, the display 14 may be a passive emissive display. The control module 17 is respectively connected to the display 14, the first detection light source 151, the second detection light source 152 and the optical detection device 16, and starts the first detection light source 151 when the color of the finger 2 needs to be detected, and starts the second detection light source 152 when the fingerprint identification detection needs to be performed.

The underscreen optical inspection system 10 also includes a processing module 18. The processing module 18 can determine that the finger 2 is a real finger by comparing the color difference values of the light returning through the finger 2 detected by the first light detecting unit 1661 at different moments in time and when the color difference value is greater than a preset color difference threshold value. The first light detection unit 1661 detects the color change by detecting a gray value of an image of a portion having a preset wavelength range in the return light via the finger 2. The first light detection unit 1661 obtains at least two images including a portion having a predetermined wavelength range in the light returned by the finger 2 at different times, and the processing module 18 compares gray level differences of the at least two images obtained by the first light detection unit 1661 to obtain the color difference. It is understood that, for the gray-level values corresponding to the same predetermined wavelength range light obtained by the first light detecting units 1661 in the same detection, the processing module 18 can perform an average operation thereon to improve the accuracy of the detected color.

It is understood that, in some other embodiments, for the first light detecting unit 1661 to respectively obtain two or more images with a predetermined wavelength range portion in the light returning through the finger 2 at different times, the processing module 18 may correspondingly analyze a gray scale difference between each two images, evaluate an average level of the gray scale difference to compare with a predetermined color difference threshold, and determine the authenticity of the finger 2 according to the comparison result. The manner for evaluating the average level of the gray scale difference value is, for example, but not limited to, calculating a standard deviation of the gray scale difference value, and the like, which is not limited in this application.

Optionally, in some embodiments, the processing module 18 may be further configured to compare the fingerprint image information acquired by the second light detection unit 1662 with a pre-stored fingerprint template, and identify the identity of the user according to the comparison result.

Alternatively, in some embodiments, the processing module 18 may obtain relevant detection data directly from the image sensor 162, such as: the grey scale value, fingerprint image information, etc. Optionally, in some other embodiments, the off-screen optical detection system 10 may further include a memory 15, the image information converted by the image sensor 162 according to the generated fingerprint image may be stored in the memory 15, and the processing module 18 may further obtain the related detection data from the memory 15.

Alternatively, in some embodiments, the control module 17 and the processing module 18 may be firmware that is solidified within the memory 15 or computer software code that is stored within the memory 15. The control module 17 and the processing module 18 are executed by the corresponding one or more processors 13 to control the relevant components to implement the corresponding functions. The Processor 13 is, for example, but not limited to, an Application Processor (AP), a Central Processing Unit (CPU), a Microprocessor (MCU), and the like. The Memory 15 includes, but is not limited to, a Flash Memory (Flash Memory), a charge Erasable Programmable read only Memory (EEPROM), a Programmable Read Only Memory (PROM), a hard disk, and the like. The memory 15 may be used to store the fingerprint template for identifying the identity of the user, various preset threshold values, image data of the fingerprint acquired by the image sensor 162, and intermediate data generated in the comparison and judgment process, etc.

Optionally, in some embodiments, the processor 13 and/or the memory 15 may be disposed within the optical detection device 16, such as: integrated on the same substrate as the image sensor 162. Optionally, in some other embodiments, the processor and/or the memory 15 may also be disposed in other positions of the electronic device 1, such as: the main circuit board of the mobile phone.

Optionally, in some embodiments, the functions of the control module 17 and/or the processing module 18 may also be implemented by hardware, for example, by any one or a combination of the following technologies: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like. It will be understood that the above-mentioned hardware for implementing the functions of the control module 17 and/or the processing module 18 may be provided within the optical detection device 16, such as: integrated on the same substrate as the image sensor 162. The hardware for implementing the functions of the control module 17 and/or the processing module 18 may also be disposed at other positions of the electronic device 1, such as: is arranged on the mainboard of the mobile phone.

Compare in prior art, optical detection system 10 obtains the finger colour difference value that detects respectively at different time quantums through the comparison under the screen of this application to judge whether the finger that detects is real finger, can prevent effectively that lawless persons from utilizing artificial finger of imitation to right optical detection system 10's under the screen recognition function attacks, has improved electronic equipment 1's security.

It should be noted that, part or all of the embodiments of the present application, and part or all of the modifications, replacements, alterations, splits, combinations, extensions, etc. of the embodiments are considered to be covered by the inventive idea of the present application without creative efforts, and belong to the protection scope of the present application.

Any reference in this specification to "one embodiment," "an embodiment," "example embodiment," etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature or structure is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature or structure in connection with other ones of the embodiments.

The orientations or positional relationships indicated by "length", "width", "upper", "lower", "left", "right", "front", "rear", "back", "front", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, which may appear in the specification of the present application, are based on the orientations or positional relationships shown in the drawings, and are only for convenience of describing the embodiments of the present application and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present application. Like reference numbers and letters refer to like items in the figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Meanwhile, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance. In the description of the present application, "plurality" or "a plurality" means at least two or two unless specifically defined otherwise. In the description of the present application, it should also be noted that, unless explicitly stated or limited otherwise, "disposed," "mounted," and "connected" are to be understood in a broad sense, e.g., they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; either directly or indirectly through intervening media, or may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

The above description is only for the specific embodiment 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. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An optical detection system for detecting a finger of a user, comprising:

a protective layer;

2. The system of claim 1, wherein the first light detecting unit comprises a first filter unit disposed on a light incident side of the first pixel unit, the first filter unit being configured to transmit light within a predetermined wavelength range to the first pixel unit.

3. The underscreen optical inspection system of claim 1, wherein each of the second light detection units includes a second filter unit disposed at a light incident side of the second pixel unit, the second filter unit being configured to transmit light of a predetermined wavelength range to the second pixel unit.

4. The underscreen optical detection system of claim 1 in which said first light detecting unit and said second light detecting unit are arranged in an array to form an array of light detecting units, wherein two of said first light detecting units are disposed adjacent to each other; alternatively, the second light detection unit is provided between the two first light detection units.

5. The underscreen optical inspection system according to claim 4 including a plurality of said first light detecting units, said first light detecting units being regularly arranged in a predetermined pattern in said array of light detecting units; alternatively, the first photodetecting units are irregularly arranged in the photodetecting unit array.

6. The system according to claim 1, wherein the first light detecting unit detects the color change by detecting a gray value of an image of a portion of the finger-returned light having a predetermined wavelength range, the control module controls the first light detecting unit to respectively acquire at least two images of the portion of the finger-returned light having the predetermined wavelength range at different times, and the processing module compares gray difference values of the at least two images acquired by the first light detecting unit as the color difference value.

7. The system of claim 1, wherein the display comprises a touch sensor, the touch sensor is configured to send a trigger signal to activate the first light detecting unit when the touch of the finger on the surface of the display is detected, the moment when the first light detecting unit starts detecting is defined as a starting point of a first time period, and the control module controls the first light detecting unit to detect the color of the light returning through the finger at least once in the first time period according to the trigger signal.

8. The off-screen optical detection system of claim 7, wherein the first time period is less than or equal to 100ms, 200ms, 300ms, or 400ms, and the processing module compares color difference values of return light from the first light detection unit via the finger detected at least two different times within the first time period to determine whether the finger is a real finger.

9. The system of claim 8, wherein the control module controls the second light detecting unit to obtain fingerprint image information of the finger in a second time period after the finger is determined to be a real finger, so as to perform fingerprint identification detection on the finger.

10. The system of claim 7, wherein the control module controls the second light detecting unit to acquire fingerprint image information of the finger in a second time period after the first time period to perform fingerprint recognition on the finger, the control module controls the first light detecting unit to detect at least one color of the returning light of the finger in a third time period after the second time period, and the processing module compares color difference values of the returning light of the finger detected by the first light detecting unit in the first time period and the third time period respectively to determine whether the finger is a real finger, wherein the first time period and the third time period are less than or equal to 10ms, 20ms, 30ms or 40 ms.

11. The off-screen optical detection system of claim 7, wherein the control module activates the second light detection unit to start acquiring fingerprint image information of the finger for fingerprint recognition detection while controlling the first light detection unit to detect the color of light returned through the finger according to a trigger signal.