CN111108509A

CN111108509A - Fingerprint detection device and electronic equipment

Info

Publication number: CN111108509A
Application number: CN201980004232.5A
Authority: CN
Inventors: 姚国峰; 沈健; 纪登鑫
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2019-08-08
Filing date: 2019-08-08
Publication date: 2020-05-05
Anticipated expiration: 2039-08-08
Also published as: CN111108509B; CN211349375U; WO2021022560A1; WO2021022596A1

Abstract

The utility model provides a fingerprint detection device is applicable to the electronic equipment that has the display screen and in order to realize optical fingerprint detection under the screen, includes: the micro prism array is arranged below the display screen; an optical assembly disposed below the microprism array; an array of optical sensing units disposed below the optical assembly, the array of optical sensing units including at least one optical sensing unit disposed below each microprism in the array of microprisms. The microprism array converts the optical signal which is reflected by the finger and inclined relative to the display screen into a signal which is vertical relative to the display screen, so that the optical loss of the optical signal reflected by the finger in the transmission process can be reduced, and the signal quantity received by the optical sensing unit array and the fingerprint identification effect are improved. In addition, since the thickness of the microprism array is generally thin, the thickness of the fingerprint detection device can be ensured to be small.

Description

Fingerprint detection device and electronic equipment

Technical Field

The present embodiments relate to the field of fingerprint detection, and more particularly, to a fingerprint detection apparatus and an electronic device.

Background

With the rapid development of the terminal industry, people pay more and more attention to the biometric identification technology, and the practicability of the more convenient under-screen biometric identification technology, such as the under-screen optical fingerprint identification technology, has become a requirement of the public.

Optical fingerprint identification technique under the screen sets up the optical fingerprint module in the display screen under, through gathering optical fingerprint image, realizes fingerprint identification. With the development of terminal products, the requirements on fingerprint identification performance are higher and higher. However, in some cases, for example, in the case of a dry finger, the contact area between the dry finger and the display screen is very small, the recognition response area is very small, the acquired fingerprint is discontinuous, the feature points are easily lost, and the performance of fingerprint recognition is affected.

Therefore, how to improve the performance of fingerprint identification becomes a technical problem to be solved urgently.

Disclosure of Invention

Provided are a fingerprint detection device and an electronic apparatus, which can improve fingerprint identification performance.

In a first aspect, a fingerprint detection apparatus is provided, which is suitable for an electronic device having a display screen to perform optical fingerprint detection under the screen, and includes:

the micro prism array is arranged below the display screen;

an optical assembly disposed below the microprism array;

an array of optical sensing units disposed below the optical assembly, the array of optical sensing units including at least one optical sensing unit disposed below each microprism in the array of microprisms;

a first optical signal returned from a finger above the display screen is converted into a second optical signal through the micro-prism array, the second optical signal transmits the second optical signal converted by each micro-prism in the micro-prism array to at least one optical sensing unit arranged below the same micro-prism through the optical assembly, the first optical signal is an optical signal inclined relative to the display screen, and the second optical signal is an optical signal vertical relative to the display screen;

the optical signal received by the optical sensing unit array is used for detecting the fingerprint information of the finger.

The microprism array converts the optical signal which is reflected by the finger and inclined relative to the display screen into a signal which is vertical relative to the display screen, so that the optical loss of the optical signal reflected by the finger in the transmission process can be reduced, and the signal quantity received by the optical sensing unit array and the fingerprint identification effect are improved.

In addition, since the thickness of the microprism array is generally thin, the thickness of the fingerprint detection device can be ensured to be small.

In some possible implementations, each of the microprisms in the array of microprisms includes at least one incident surface for receiving the first optical signal and one exit surface for exiting the second optical signal, wherein each of the at least one incident surface is a plane inclined with respect to the display screen and the one exit surface is a plane parallel with respect to the display screen.

In some possible implementations, the first light signal forms a first angle with a direction perpendicular to the display screen;

then, a second included angle formed by the incident surface and the exit surface of each micro prism in the micro prism array is:

wherein theta represents the second included angle,

representing said first angle, n₁Representing the refractive index, n, of the propagation medium of the incident light₂Representing the refractive index of the microprisms.

In some possible implementations, the first included angle is greater than or equal to 20 degrees.

In some possible implementations, one optical sensing unit is disposed below each incidence plane of each micro prism of the micro prism array.

In some possible implementations, the microprism array includes a plurality of microprism units distributed in an array, and each microprism unit of the plurality of microprism units includes a plurality of microprisms distributed in central symmetry.

In some possible implementations, each of the plurality of microprism units comprises 4 microprisms.

In some possible implementations, the microprism array includes a plurality of microprisms distributed in an array.

In some possible implementations, a plurality of optical sensing units are disposed below each incidence surface of each micro prism in the micro prism array.

In some possible implementations, the micro-prism array includes a plurality of micro-prisms arranged along a first direction, and a plurality of optical sensing units arranged along a second direction are disposed below each incident surface of each of the plurality of micro-prisms, and the first direction is perpendicular to the second direction.

In some possible implementations, each microprism in the array of microprisms is any of:

right angle triangle prism, isosceles triangle prism, right angle trapezoidal prism and isosceles trapezoidal prism.

In some possible implementations, the optical assembly includes:

a micro lens array disposed below the micro prism array;

the at least one light blocking layer is arranged between the micro lens array and the optical sensing unit array, and an opening corresponding to each optical sensing unit in the optical sensing unit array is arranged in each light blocking layer in the at least one light blocking layer;

the micro lens array is used for receiving the second optical signal converted by the micro prism array and transmitting the second optical signal to the optical sensing unit array through the opening of the at least one light blocking layer.

Compared with the scheme of directly converging the inclined light signals through the micro lens, the light signals which are reflected by the finger and inclined relative to the display screen are converted into signals vertical to the display screen through the micro prism array, then the vertical light signals are converged by the micro lens and the micro-hole diaphragm serving as the optical assembly, so that the micro lens does not have a shadow area, and the signal quantity and the fingerprint identification effect which can be received by the optical sensing unit array are improved.

In some possible implementations, the at least one light-blocking layer includes a bottom light-blocking layer disposed at a back focal plane location of the microlens array.

In some possible implementations, the bottom light blocking layer is a metal wiring layer of the array of photo-sensing units.

In some possible implementations, the at least one light-blocking layer includes a plurality of light-blocking layers, and the apertures in each light-blocking layer corresponding to the same microlens are sequentially reduced from top to bottom.

In some possible implementations, the optical assembly is a straight-hole collimator, and each optical sensing unit in the array of optical sensing units corresponds to at least one collimating hole in the straight-hole collimator; the straight hole collimator is used for receiving the second optical signal converted by the microprism array and transmitting the second optical signal to the optical sensing unit array through a collimating hole in the straight hole collimator.

Compared with the scheme of screening optical signals directly through the inclined-hole collimator, the optical signals which are reflected by fingers and inclined relative to the display screen are converted into signals vertical to the display screen through the micro-prism array, and then the optical signals are screened through the straight-hole collimator, so that the manufacturing difficulty and the cost of the collimator are effectively reduced.

In some possible implementations, the array of optical sensing units and the straight-hole collimator are integrally disposed.

In some possible implementations, the fingerprint detection apparatus further includes:

the optical filter is arranged at least one of the following positions:

above the microprism array;

between the microprism array and the optical component;

an interior of the optical assembly; and

the optical assembly and the optical sensing unit array.

The optical loss is small for a vertical light signal when only the optical filter is used, and there is no need to customize the optical filter, thereby reducing the manufacturing complexity thereof, as compared to when the oblique light signal passes directly through the optical filter.

In a second aspect, a terminal device is provided, which includes a display screen and the fingerprint detection apparatus of the first aspect.

Drawings

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

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

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

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

Fig. 5 shows a schematic diagram of a fingerprint detection device according to an embodiment of the present application.

Fig. 6 is a schematic structural diagram showing another fingerprint detection device according to an embodiment of the present application.

Fig. 7 shows a schematic cross-sectional view of a further fingerprint detection device according to an embodiment of the present application.

Fig. 8 is a schematic view illustrating a process in which a micro prism changes the incident direction of light according to an embodiment of the present application.

Fig. 9 is a perspective view of the microprism array of fig. 7.

Fig. 10 is a schematic configuration diagram in a plan view of the fingerprint detection device shown in fig. 7.

Fig. 11 is a schematic view of a deformed configuration of the fingerprint detection device shown in fig. 7.

Fig. 12 and 13 are plan views of the microprism unit of fig. 11.

Fig. 14 is a schematic configuration diagram of a field of view of a fingerprint detection device according to an embodiment of the present application.

Fig. 15 is another schematic view of a deformed configuration of the fingerprint detection device shown in fig. 7.

Detailed Description

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

The technical scheme of the embodiment of the application can be applied to various electronic devices. Such as portable or mobile computing devices, e.g., smart phones, laptops, tablets, gaming devices, etc., and other electronic devices, e.g., electronic databases, automobiles, Automated Teller Machines (ATMs), etc. However, the present embodiment is not limited thereto.

The technical scheme of the embodiment of the application can be used for the biological feature recognition technology. The biometric technology includes, but is not limited to, fingerprint recognition, palm print recognition, iris recognition, face recognition, and living body recognition. For convenience of explanation, the fingerprint identification technology is described as an example below.

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

Fingerprint identification technique is installed in the display screen below with fingerprint identification module under the screen to realize carrying out the fingerprint identification operation in the display area of display screen, need not set up the fingerprint collection region in the positive region except that the display area of electronic equipment. Specifically, the fingerprint identification module uses the light that returns from the top surface of electronic equipment's display module to carry out fingerprint response and other response operations. This returned light carries information about objects (e.g., fingers) in contact with or in proximity to the top surface of the display assembly, and the fingerprint recognition module located below the display assembly performs underscreen fingerprint recognition by capturing and detecting this returned light. The fingerprint identification module can be designed to realize desired optical imaging by properly configuring an optical element for collecting and detecting returned light, so as to detect fingerprint information of the finger.

Correspondingly, (In-display) fingerprint identification technique means installs inside the display screen fingerprint identification module or partial fingerprint identification module In the screen to realize carrying out the fingerprint identification operation In the display area of display screen, need not set up the fingerprint collection region In the positive region except that the display area of electronic equipment.

It should be noted that, for convenience of description, like reference numerals denote like parts in the embodiments of the present application, and a detailed description of the like parts is omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the present application and the overall thickness, length, width and other dimensions of the integrated device shown in the drawings are only exemplary and should not constitute any limitation to the present application.

Fig. 1 to 4 are schematic views showing an electronic device to which the embodiment of the present application can be applied. Fig. 1 and 3 are schematic orientation diagrams of the electronic device 10, and fig. 2 and 4 are schematic cross-sectional diagrams of the electronic device 10 shown in fig. 1 and 3, respectively.

Referring to fig. 1 to 4, the electronic device 10 may include a display 120 and an optical fingerprint identification module 130.

The display 120 may be a self-luminous display employing display units having self-luminous properties as display pixels. For example, the display screen 120 may be an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. In other alternative embodiments, the Display 120 may also be a Liquid Crystal Display (LCD) or other passive light emitting Display, which is not limited in this embodiment of the present application. Further, the display screen 120 may also be specifically a touch display screen, which not only can perform image display, but also can detect a touch or pressing operation of a user, thereby providing a human-computer interaction interface for the user. For example, in one embodiment, the electronic device 10 may include a Touch sensor, which may be embodied as a Touch Panel (TP), which may be disposed on a surface of the display screen 120, or may be partially or wholly integrated within the display screen 120, thereby forming the Touch display screen.

The optical fingerprint module 130 includes an optical fingerprint sensor including a sensing array 133 having a plurality of optical sensing units 131 (which may also be referred to as photosensitive pixels, pixel units, etc.). The sensing array 133 is located in an area or a sensing area thereof, which is the fingerprint detection area 103 (also called a fingerprint collection area, a fingerprint identification area, etc.) of the optical fingerprint module 130.

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

With continued reference to fig. 1, the fingerprint detection area 103 may be located within a display area of the display screen 120. In an alternative embodiment, the optical fingerprint module 130 may be disposed at other positions, such as the side of the display screen 120 or the edge opaque area of the electronic device 10, and the optical path is designed to guide the optical signal from at least a part of the display area of the display screen 120 to the optical fingerprint module 130, so that the fingerprint detection area 103 is actually located in the display area of the display screen 120.

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

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

In some embodiments of the present application, 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, for example, the optical component 132 is attached to the chip, or some components of the optical component 132 are integrated into the chip.

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

For example, the light path is guided by the light collimation method, and the fingerprint detection area 103 of the optical fingerprint module 130 may be designed to be substantially consistent with the area of the sensing array of the optical fingerprint module 130.

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

The following is an exemplary description of the optical assembly 132 that may include an optical path directing structure.

Taking the optical Collimator with the through hole array having the high aspect ratio as an example, the optical Collimator may specifically be a Collimator (collimater) layer made of a semiconductor silicon wafer, and the optical Collimator has a plurality of collimating units or micropores, the collimating units may specifically be small holes, in reflected light reflected from a finger, light perpendicularly incident to the collimating units may pass through and be received by sensor chips below the collimating units, and light with an excessively large incident angle is attenuated by multiple reflections inside the collimating units, so that each sensor chip can basically only receive reflected light reflected from fingerprint lines directly above the sensor chip, and image resolution can be effectively improved, and fingerprint identification effect is improved. The optical collimator may include a straight collimator and an inclined collimator, an axial direction of the collimating unit or the micro hole in the straight collimator may be perpendicular to the sensing array 133 of the optical fingerprint module 130, and an axial direction of the collimating unit or the micro hole in the inclined collimator may be inclined with respect to the sensing array 133 of the optical fingerprint module 130.

Taking the optical path design of the optical Lens adopted by the optical path guiding structure as an example, the optical path guiding structure may be an optical Lens (Lens) layer having one or more Lens units, such as a Lens group consisting of one or more aspheric lenses, for converging the reflected light reflected from the finger to the sensing array 133 of the light detecting portion 134 therebelow, so that the sensing array 133 may perform imaging based on the reflected light, thereby obtaining the fingerprint image of the finger. Further, the optical lens layer may further be formed with a pinhole or a micropore diaphragm in the optical path of the lens unit, for example, one or more light-shielding sheets may be formed in the optical path of the lens unit, wherein at least one light-shielding sheet may be formed with a light-transmitting micropore in the optical axis or the optical central region of the lens unit, and the light-transmitting micropore may serve as the pinhole or the micropore diaphragm. The pinhole or the micro-aperture diaphragm can cooperate with the optical lens layer and/or other optical film layers above the optical lens layer to enlarge the field of view of the optical fingerprint module 130, so as to improve the fingerprint imaging effect of the optical fingerprint module 130.

Taking the optical path design in which the optical path guiding structure employs a Micro-Lens (Micro-Lens) layer as an example, the optical path guiding structure may be a Micro-Lens array including a plurality of Micro-lenses, which may be formed above the sensing array 133 of the light detecting portion 134 through a semiconductor growth process or other processes, and each of the Micro-lenses may respectively correspond to one of the sensing units of the sensing array 133. And other optical film layers, such as a dielectric layer or a passivation layer, can be formed between the microlens layer and the sensing unit. More specifically, a light blocking layer (or referred to as a light shielding layer, a light blocking layer, or the like) having micro holes (or referred to as open holes) may be further included between the microlens layer and the sensing unit, wherein 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 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 for optical fingerprint imaging.

It should be understood that several of the implementations described above for the optical path directing structure may be used alone or in combination.

For example, a microlens layer may be further disposed above or below the collimator layer or the optical lens layer. Of course, when the collimator layer or the optical lens layer is used in combination with the microlens layer, the specific lamination structure or optical path thereof may need to be adjusted according to actual needs.

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

Fingerprint identification module 140 may be configured to collect fingerprint information (e.g., fingerprint image information) of a user.

Taking the display screen 120 as an example, the display screen has a self-luminous display unit, such as an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. The optical fingerprint module 130 may use a display unit (i.e., an OLED light source) of the OLED display screen 120 located in the fingerprint detection area 103 as an excitation light source for optical fingerprint detection. When the finger 140 is pressed against the fingerprint detection area 103, the display 120 emits a beam of light 111 towards the 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 (transmitted light) is formed by scattering through the inside of the finger 140. In the related patent application, the above-mentioned reflected light and scattered light are collectively referred to as reflected light for convenience of description. Because the ridges (ridges) 141 and the valleys (valley)142 of the fingerprint have different light reflection capabilities, the reflected light 151 from the ridges and the reflected light 152 from the valleys of the fingerprint have different light intensities, and after passing through the optical assembly 132, the reflected light is received by the sensing array 133 in the optical fingerprint module 130 and converted into corresponding electrical signals, i.e., fingerprint detection signals; fingerprint image data can be obtained based on the fingerprint detection signal, and fingerprint matching verification can be further performed, so that an optical fingerprint identification function is realized in the electronic device 10.

In other alternatives, the optical fingerprint module 130 may also use an internal light source or an external light source to provide an optical signal for fingerprint detection and identification. In this case, the optical fingerprint module 130 may be applied to not only a self-luminous display screen such as an OLED display screen, but also a non-self-luminous display screen such as a liquid crystal display screen or other passive luminous display screens.

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 module 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 module 130; alternatively, the optical fingerprint module 130 may be disposed below the backlight module, and the backlight module may open holes or perform other optical designs on film layers such as a diffusion sheet, a brightness enhancement sheet, and a reflection sheet to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint module 130. When the optical fingerprint module 130 is used to provide an optical signal for fingerprint detection by using an internal light source or an external light source, the detection principle is consistent with the above description.

In a specific implementation, the electronic device 10 may further include a transparent protective cover, which may be a glass cover or a sapphire cover, located above the display screen 120 and covering the front surface of the electronic device 10. Therefore, 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.

On the other hand, optics fingerprint module 130 can only include an optics fingerprint sensor, and the area of the fingerprint detection area 103 of optics fingerprint module 130 is less and the rigidity this moment, therefore the user need press the finger to the specific position of fingerprint detection area 103 when carrying out the fingerprint input, otherwise optics fingerprint module 130 probably can't gather the fingerprint image and cause user experience not good. In other alternative embodiments, the optical fingerprint module 130 may specifically include a plurality of optical fingerprint sensors. A plurality of optics fingerprint sensor can set up side by side through the concatenation mode the below of display screen 120, just a plurality of optics fingerprint sensor's response area constitutes jointly optics fingerprint module 130's fingerprint detection area 103. Thereby the fingerprint detection area 103 of optical fingerprint module 130 can extend to the main area of the lower half of display screen, extend to the finger and press the region conventionally promptly to realize blind formula fingerprint input operation of pressing. Further, when the number of the optical fingerprint sensors is sufficient, the fingerprint detection area 103 may also be extended to a half display area or even the entire display area, thereby realizing half-screen or full-screen fingerprint detection.

Referring to fig. 3 and 4, the optical fingerprint module 130 in the electronic device 10 may include a plurality of optical fingerprint sensors, the plurality of optical fingerprint sensors may be arranged below the display screen 120 side by side in a manner such as splicing, and sensing areas of the plurality of optical fingerprint sensors jointly form the fingerprint detection area 103 of the optical fingerprint device 130.

Further, the optical assembly 132 may include a plurality of optical path guiding structures, each of which corresponds to one optical fingerprint sensor (i.e., the sensing array 133) and is attached above the corresponding optical fingerprint sensor. Alternatively, the plurality of optical fingerprint sensors may share an integral optical path directing structure, i.e. the optical path directing structure has an area large enough to cover the sensing array of the plurality of optical fingerprint sensors.

Taking the optical collimator with the through hole array having the aspect ratio as an example of the optical assembly 132, when the optical fingerprint module 130 includes a plurality of optical fingerprint sensors, one or more collimating units may be configured for one optical sensing unit in the optical sensing array of each optical fingerprint sensor, and the collimating units are attached to and disposed above the corresponding optical sensing units. Of course, the plurality of optical sensing units may also share one collimating unit, i.e. the one collimating unit has a sufficiently large aperture to cover the plurality of optical sensing units. Because a collimation unit can correspond a plurality of optical sensing units or an optical sensing unit corresponds a plurality of collimation units, the spatial period of display screen 120 and optical fingerprint sensor's spatial period's correspondence has been destroyed, therefore, even the spatial structure of the luminous display array of display screen 120 and optical fingerprint sensor's optical sensing array's spatial structure are similar, also can effectively avoid optical fingerprint module 130 to utilize the optical signal through display screen 120 to carry out fingerprint imaging and generate moire fringe, optical fingerprint module 130's fingerprint identification effect has effectively been improved.

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

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

For example, the number, size and arrangement of the fingerprint sensors are not specifically limited, and may be adjusted according to actual requirements. For example, the number of the plurality of fingerprint sensors of the optical fingerprint module 130 may be 2, 3, 4 or 5, and the plurality of fingerprint sensors may be distributed in a square or circle shape.

Optical fingerprint module 130 can adopt relative display screen 120 vertically light signal detection fingerprint information, also can adopt relative the light signal detection fingerprint information of display screen 120 slope, and this embodiment of this application does not do specifically to limit to this.

A fingerprint detection device for detecting fingerprint information based on oblique optical signals according to an embodiment of the present application will be described with reference to fig. 5 and 6. Fig. 5 shows a schematic view of a fingerprint detection device 20 according to an embodiment of the present application. Fig. 6 shows a schematic configuration diagram of the fingerprint detection device 30 according to the embodiment of the present application. The fingerprint detection device 20 shown in fig. 5 and the fingerprint detection device 30 shown in fig. 6 are both suitable for the electronic device 10 shown in fig. 1 to 4, or the fingerprint detection device 20 or the fingerprint detection device 30 may be the optical fingerprint module 130 shown in fig. 1 to 4.

As an example, referring to fig. 5, the fingerprint detection device 20 may include a microlens 21, a micro aperture stop 22 disposed on a back focal plane 211 of the microlens 21, a light sensing unit 23 disposed below the stop 22, and an optical filter 25 disposed above the microlens 21.

When the incident angle is

After entering the fingerprint detection device 20, the finger reflection light 24 firstly passes through the optical filter 25, the optical filter 25 has a high light transmittance to the visible light band and cuts off the infrared light, and the function of the optical filter is to prevent the infrared band light in the sunlight from penetrating the finger and interfering the fingerprint image collection. The reflected light 24 then passes through the microlens 21 and is focused to a certain point F on the microlens back focal plane 211₁. Wherein F₁From the back focus F of the microlens 21₀Distance F of₀F₁Can be expressed approximately as:

where r is the radius of curvature of the microlens 21 and n is the refractive index of the material of the microlens 21. The aperture 22 being arranged at F₁The non-light-transmitting layer 220 is disposed in the region except the micropore diaphragm 22, and the size of the diaphragm aperture determines the angle range of the incident light that can pass through

Only the incident angle is

To

The finger-reflected light 24 within the range can reach the photosensitive unit 23. The combination of the micro-lens 21 and the aperture stop 22 can realize the angle screening of the incident light, and the incident light of the non-target angle is blocked by the non-transparent layer 220.

However, when it comes to receiving high angle optical signals (e.g. angle of incidence)

Greater than 30 degrees), the solution shown in fig. 5 faces two problems: firstly, the transmittance of the filter 25 for the large-angle oblique incident light is reduced relative to the transmittance for the vertical incident light; secondly, a part of the area of the microlens 21 (e.g. the area 241 in fig. 5) cannot perform the convergence function due to the shadow effect (lens shading effect).

The above two points will cause the fingerprint detection device 20 to have a large light loss when receiving a large angle of oblique incident light, so that it is necessary to obtain a sufficient amount of signals by prolonging the exposure time of the fingerprint detection device 20, but this will cause a long fingerprint recognition time, which affects the user experience.

As another example, referring to fig. 6, the fingerprint detection device 30 may include an optical filter 35, an inclined hole collimator 36 (including a plurality of inclined holes 361) disposed below the optical filter 35, and a photosensitive unit 33 below the inclined hole collimator 36. Because the angle between the direction of the preset inclined hole 361 and the direction of the normal line 310 is

Therefore, the light receiving unit 33 can receive only the finger reflection light 34 at the incident angle of

Or is close to

The oblique optical signal of (1).

However, the solution shown in fig. 6 still has a problem of low transmittance of the filter 35.

In addition, the process for manufacturing the inclined hole collimator 36 is relatively complex, the manufacturing difficulty is high, and the method is not suitable for large-scale production.

The embodiment of the application can be applied to detection of various fingers, and is particularly suitable for detection of dry fingers. The term "dry finger" refers to a relatively dry finger. The scheme of present fingerprint identification is not good enough to the fingerprint identification effect of dry finger, and the fingerprint identification's that this application embodiment provided scheme can promote the fingerprint identification performance to dry finger.

In particular, the embodiment of the present application solves the problem of light loss when the fingerprint detection device 20 and the fingerprint detection device 30 receive large-angle incident light, thereby shortening the exposure time of the fingerprint detection device, accelerating the speed of fingerprint identification and improving the user experience.

The embodiment of the application is suitable for the display screen below in order to realize optical fingerprint detection under the screen. Fig. 7 shows a schematic diagram of a fingerprint detection device 40 according to an embodiment of the present application. The fingerprint detection device 40 may be suitable for the electronic device 10 shown in fig. 1 to 4, or the device 40 may be the optical fingerprint module 130 shown in fig. 1 to 4.

Referring to fig. 7, the fingerprint detection device 40 may include a light guide portion 41 and a light detection portion 42. Wherein the light guiding section 41 may be used to guide the light signal reflected via the finger to the light detecting section 42. The light guide part 41 may be included as a micro-prism array 410, which may include a plurality of micro-prisms (micro-prisms), such as a first micro-prism 410a, a second micro-prism 410b, and a third micro-prism 410 c. The micro-prism array 410 may be used to convert a first optical signal reflected via a finger into a second optical signal. The first optical signal may be an optical signal inclined with respect to the display screen, and the second optical signal may be an optical signal perpendicular to the display screen. Alternatively, the first optical signal may be an optical signal inclined with respect to the upper surface of the light detecting section 42, and the second optical signal may be an optical signal perpendicular to the upper surface of the light detecting section 42.

With continued reference to fig. 7, the light detecting portion 42 may include an optical sensing unit array 424, which may include a plurality of optical sensing units. For example, the optical sensing unit array 424 may include a first optical sensing unit 424a, a second optical sensing unit 424b, and a third optical sensing unit 424 c. The optical sensing unit array 424 receives the optical signal for detecting the fingerprint information of the finger. Wherein at least one optical sensing unit is disposed below each micro-prism in the micro-prism array 410; for example, at least a first optical sensing unit 424a is disposed below the first micro-prism 410a, at least a second optical sensing unit 424b is disposed below the second micro-prism 410b, and at least a third optical sensing unit 424c is disposed below the third micro-prism 410 c.

Further, the light detecting portion 42 may further include a metal layer 421 and a dielectric layer 423 of the intermetal 421. The metal layer 421 can be a metal wiring layer of the optical sensing unit array 424, and is used for electrically interconnecting the optical sensing units in the optical sensing unit array 424 and electrically connecting the optical sensing unit array 424 to an external device, so as to implement internal and external communication of the fingerprint detection apparatus 40.

Of course, the optical detection part may include a plurality of metal layers 421. For example, the light detection part 42 may include three metal layers 421, a dielectric layer 423 may be disposed between the three metal layers 421 and between the metal layers 421 and the optical sensing cell array 424, and a material of the dielectric layer 423 may be a transparent material.

In some embodiments of the present application, the light guiding portion 41 may further include an optical component (e.g., the optical component 132 shown in fig. 1 or fig. 2) disposed between the micro-prism array 410 and the optical sensing unit array 414, and the optical component is used for screening or separating the second optical signal converted by the micro-prism array 410. That is, the optical assembly may be used to screen out a portion of the second optical signal converted by the microprism array 410 and direct the portion of the second optical signal to a specific optical sensing unit in the optical sensing unit array 424.

For example, the optical assembly is used to guide the second optical signal converted by each micro-prism to an optical sensing unit under the same micro-prism. That is, after a first optical signal returned from a finger above the display screen is converted into a second optical signal by the micro-prism array 410, the second optical signal transmits the second optical signal converted by each micro-prism in the micro-prism array 410 to at least one optical sensing unit disposed below the same micro-prism through the optical assembly. For example, the optical assembly may be configured to guide the second optical signal converted by the first micro-prism 410a to the first optical sensing unit 424a, further configured to guide the second optical signal converted by the second micro-prism 410b to the second optical sensing unit 424b, and further configured to guide the second optical signal converted by the third micro-prism 410c to the third optical sensing unit 424 c.

Based on the above technical solution, the micro prism array 410 converts the optical signal reflected by the finger and inclined with respect to the display screen into a signal vertical to the display screen, so as to reduce the optical loss of the optical signal reflected by the finger in the transmission process, thereby improving the amount of the signal received by the optical sensing unit array 424 and the fingerprint identification effect.

In addition, since the thickness of the microprism array 410 is generally thin, it is possible to ensure that the thickness of the fingerprint detection apparatus 40 is small.

Of course, the optical assembly may also guide the converted second optical signal of each micro-prism in the micro-prism array 410 to an oblique lower side of the same micro-prism to reduce the thickness of the fingerprint detection device 40. For example, the optical assembly may be used to guide the converted second optical signal of the first micro-prism 410a to the second optical sensing unit 424b, i.e., the optical sensing unit below the second micro-prism 410 b. This is not particularly limited by the embodiments of the present application.

With continued reference to fig. 7, the optical assembly may employ a microlens array and at least one light blocking layer, wherein the microlens array may be disposed below the microprism array 410 and comprises a plurality of microlenses; the at least one light-blocking layer may be disposed between the microlens array and the optical sensing unit array 424, and a plurality of openings corresponding to the plurality of optical sensing units are disposed in each of the at least one light-blocking layer; the array of optical sensing units 424 is used for receiving the optical signal converged by the microlens array and transmitted through the opening of the at least one light blocking layer. Or the microlens array, is used to receive the second optical signal converted by the microprism array 410 and transmit the second optical signal to the optical sensing unit array 424 through the opening of the at least one light blocking layer.

As an example, the microlens array may include a first microlens 412a, a second microlens 412b, and a third microlens 412 c. The at least one light-blocking layer includes a first light-blocking layer 414 and a second light-blocking layer, where the first light-blocking layer 414 and the second light-blocking layer are both provided with an opening corresponding to each microlens in the microlens array. For example, the metal layer 421 at the top layer position in the light detection array 42 can be reused as the second light-blocking layer to simplify the structure of the fingerprint detection device 40. The first light blocking layer 414 has a first opening 415a corresponding to the first microlens 412a, a second opening 415b corresponding to the second microlens 412b, and a third opening 415c corresponding to the third microlens 412 c. Similarly, a fourth opening 422a corresponding to the first microlens 412a, a fifth opening 422b corresponding to the second microlens 412b, and a sixth opening 422c corresponding to the third microlens 412c are disposed in the second light-blocking layer.

The first optical sensing unit 424a is configured to receive the optical signal converged by the first microlens 412a and transmitted through the first opening 415a and the fourth opening 422 a. The second optical sensing unit 424b is configured to receive the optical signal converged by the second microlens 412b and transmitted through the second opening 415b and the fifth opening 422 b. The third optical sensing unit 424c is configured to receive the optical signal converged by the third microlens 412c and transmitted through the third opening 415c and the sixth opening 422 c.

Compared with the scheme shown in fig. 5, the microprism array 410 converts the light signal reflected by the finger and inclined relative to the display screen into a signal vertical to the display screen, and then the vertical light signal is converged by using the micro lens and the micro aperture stop as an optical component, so that the micro lens in the micro lens array does not have a shadow area, and the signal quantity and the fingerprint identification effect which can be received by the optical sensing unit array 424 are improved.

With reference to fig. 7, the at least one light-blocking layer may include a plurality of light-blocking layers, and the apertures of the openings corresponding to the same microlens in each light-blocking layer are sequentially reduced from top to bottom. For example, the aperture of the opening provided in the first light-blocking layer 414 is larger than the aperture of the opening provided in the second light-blocking layer. For example, the first opening 415a has a larger aperture than the fourth opening 422 a.

Of course, the apertures of the openings corresponding to the same microlens in each light blocking layer from top to bottom may be the same, which is not limited in this application.

With continued reference to fig. 7, the at least one light-blocking layer may include a bottom light-blocking layer disposed at a back focal plane of the microlens array, wherein the back focal plane of the microlens array may be a plane formed by the back focal point of each microlens in the microlens array. The bottom light-blocking layer is provided with an opening corresponding to each optical sensing unit in the optical sensing unit array 424, wherein each optical sensing unit in the optical sensing unit array 424 receives a light signal through the opening in the bottom light-blocking layer corresponding to the same optical sensing unit. Optionally, the bottom light-blocking layer is a metal wiring layer of the optical sensing unit array 424 (i.e. the metal layer 421 in the light detection portion 42), so as to simplify the structure of the fingerprint detection apparatus 40. Of course, the metal layer 421 at any position in the light detection section 42 can be multiplexed as the bottom light blocking layer. For example, the metal layer 421 located at the top position, the middle position, or the bottom position in the light detection section 42 may be multiplexed as the bottom light blocking layer. For example, as shown in fig. 7, the metal layer 421 located at the top layer position in the light detection section 42 is multiplexed as the bottom light blocking layer. The material of the at least one light-blocking layer may be an opaque material, so that the open area of the at least one light-blocking layer may be used for transmitting optical signals, and the non-open area of the at least one light-blocking layer may block optical signals that are not allowed to pass through, thereby preventing the invalid optical signals from interfering with the optical sensing unit array 424.

As an example, the bottom light-blocking layer may be a second light-blocking layer, that is, the second light-blocking layer may be disposed at a back focal plane position of the microlens array, and the second light-blocking layer is provided with an opening in an optical axis direction of each microlens of the microlens array. The second light-blocking layer is provided with a fourth aperture 422a in the optical axis direction of the first microlens 412a, for example. Further, the second light-blocking layer may also be provided inside the light detection section 42, for example, formed using a metal layer in a post-chip process (BEOL). That is, the metal wiring layer of the optical sensing unit array 424 is reused as the bottom light-blocking layer of the at least one light-blocking layer, so as to reduce the thickness of the fingerprint detection device 40. Further, the light guiding portion 41 may also be integrated with the light detecting portion 42 on the same chip to further reduce the thickness of the fingerprint detection device 40 and avoid occupying space of other modules (e.g. a battery) in the electronic device.

With continued reference to fig. 7, the fingerprint sensing device 40 may further include an optical filter 416. For example, the filter 416 may be an infrared cut filter (IR cut filter).

The loss of light in the vertical light signal through the filter is small compared to the oblique light signal passing directly through the filter 416, and the filter 416 need not be customized, thereby reducing its manufacturing complexity.

The optical filter 416 is used to reduce undesired ambient light in fingerprint sensing to improve the optical sensing of the optical sensing element array 424 to the received light. The filter 416 may specifically be used to filter out light of a particular wavelength, e.g., near infrared light and portions of red light, etc. For example, a human finger absorbs most of the energy of light with a wavelength below 580nm, and if one or more optical filters or optical filter layers are designed to filter light with a wavelength from 580nm to infrared, the effect of ambient light on the optical detection in fingerprint sensing can be greatly reduced.

For example, the optical filter 416 may include one or more optical filters, which may be configured, for example, as a band pass filter to allow transmission of light emitted by the OLED screen while blocking other light components such as infrared light in sunlight. Such optical filtering can effectively reduce background light caused by sunlight when the fingerprint detection device 40 is used outdoors under a screen. The one or more optical filters may be implemented, for example, as optical filter coatings formed on one or more continuous interfaces, or may be implemented as one or more discrete interfaces. In addition, the light inlet surface of the optical filter 416 may be provided with an optical inorganic coating or an organic black coating, so that the reflectivity of the light inlet surface of the optical filter is lower than a first threshold value, for example, 1%, thereby ensuring that the optical sensing unit array 424 can receive enough optical signals, and further improving the fingerprint identification effect.

It should be understood that the optical filter 416 may be fabricated at any position along the optical path from the reflected light formed by the reflection of the finger to the optical sensing unit array 424, which is not specifically limited in the embodiments of the present application.

By way of example, the filter 416 may be disposed at any of the following locations: above the microprism array 410; between the microprism array 410 and the optical component; an interior of the optical assembly; and between the optical assembly and the array of optical sensing elements 424. For example, the optical filter 416 is disposed on the lower surface of the micro-prism array 410, and the optical filter 416 is configured to receive the second optical signal (i.e., the optical signal perpendicular to the optical filter 416) converted by the micro-prism array 410, so that the optical loss of the second optical signal in the optical filter 416 is effectively reduced, and the fingerprint identification effect is further improved.

Taking the optical filter 416 fixed on the upper surface of the photo sensor cell array 424 by a fixing device as an example, the optical filter 270 and the photo sensor pixel array 240 may be fixed by dispensing on the non-photosensitive region of the photo sensor pixel array 240, and a gap exists between the optical filter 270 and the photosensitive region of the photo sensor pixel array 240. Or the lower surface of the filter 270 is fixed on the upper surface of the optically sensitive pixel array 240 by glue with a refractive index lower than a preset refractive index, for example, the preset refractive index includes but is not limited to 1.3.

With continued reference to fig. 7, the fingerprint detection device 40 may further include a planarization layer 411 disposed above the microlens array, and an optical path layer 413 disposed below the microlens array. The planarization layer 411 and the light path layer 413 may be formed of a light transmissive material, and a first light blocking layer 414 formed of a light opaque material may be disposed within the light path layer 413.

It should be understood that the microprism array 410 of the present application may be configured to receive only light at a particular angle

Incident reflected light signals from the finger (e.g., reflected light 34 shown in fig. 6). Take the second microprism 410b as an example, take an angle

The incident finger reflection light 34 passes through the two micro prisms 410b and becomes a vertical light signal. The vertical optical signal passes through the optical filter 416 to filter out the light in the non-target wavelength band, and then passes through the second micro lens 412b to converge at the back focus under the action of the micro lens, i.e. converge in the micro aperture 422b, and the optical signal passing through the micro aperture 422b is absorbed by the corresponding optical sensing unit 424b and converted into a corresponding electrical signal according to a certain proportion to be output. Because the light intensity of the reflected light Iv from the fingerprint valley is greater than the reflected light Ir from the fingerprint ridge, the electrical signal output by the acquisition unit corresponding to the valley is stronger, and the image is brighter; the electric signal output by the acquisition unit corresponding to the ridge is weak, the image is dark, and finally a clear fingerprint image with certain contrast is output. To be provided with

The reflected light of the angle incidence is still an oblique light signal after passing through the second micro-prism 410b, and is in the second micro-prism410b are focused on an area other than the focal point on the back focal plane, and thus cannot reach the second microprism 410b, and thus cannot form an image.

The principle of converting the first optical signal reflected by the finger into the second optical signal in the embodiment of the present application is described below with reference to fig. 8.

Fig. 8 is a schematic view illustrating a process in which a micro prism changes the incident direction of light according to an embodiment of the present application. For convenience of explanation, it is assumed that an exit surface of each of the plurality of microprisms is parallel to the display screen, and an incident surface of each of the plurality of microprisms forms a second included angle with the exit surface, such that the microprism array is used to convert the first optical signal into the second optical signal. It should also be understood that fig. 8 only illustrates the second microprisms 410b of the microprism array 410 of fig. 7, but the present application is not limited thereto.

Referring to fig. 8, the second micro-prism 410b includes an incident surface 501, an exit surface 502 and at least one supporting surface 500. When the incident light (i.e., the reflected light 24 in fig. 5) represented by 51 reaches the incident surface 501, part of the light is reflected to form reflected light 53, and the remaining part is refracted to form refracted light 52 and is emitted from the emission surface 502.

Assuming that the first optical signal forms a first included angle with a direction perpendicular to the display screen, the second included angle and the first included angle may satisfy the following relationship:

wherein theta represents the second included angle,

Suppose that

And the second is a littleThe refractive index of the material of the prism 410b is 1.55, and since the incident light 51 is incident from air, n is₁1. The second included angle theta of the second microprism 410b can be calculated to be 36 deg. by the above formula. That is, the second micro-prism 410b having the second included angle of 36 ° may convert the first optical signal having the first included angle of 30 ° into the second optical signal.

It should be noted that, since the optical signal reflected by the finger includes optical signals in various directions, the embodiment of the present application does not limit the specific value of the first included angle. The angle of the included angle formed by the incident plane and the exit plane of the microprisms in the microprism array 410 can be determined by one skilled in the art according to the angle of the oblique light signal reflected via the finger to be actually collected. Preferably, the first included angle is greater than or equal to 20 degrees. That is, the fingerprint detection device 40 can detect fingerprint information of a finger based on a large-angle oblique light signal, thereby improving a fingerprint recognition effect.

It should be further noted that the microprisms with a specific angle in the embodiment of the present application may be manufactured by a process such as nanoimprint lithography or gray-scale lithography, which is mature and will not be described herein again.

A specific implementation of the microprism array 410 of the present embodiment is described below.

In some embodiments of the present application, each of the micro prisms of the micro prism array 410 includes at least one incident surface for receiving the first optical signal and one exit surface for exiting the second optical signal, wherein each of the at least one incident surface is a plane inclined with respect to the display screen, and the one exit surface is a plane parallel with respect to the display screen.

As an example, an optical sensing unit is disposed under each incident surface of each micro prism of the micro prism array 410, which may be applied to the micro prism array 410 composed of micro prisms having a smaller size. For example, the microprism array 410 may include a plurality of microprism units distributed in an array, each microprism unit of the plurality of microprism units including a plurality of microprisms distributed in a central symmetry, e.g., each microprism unit of the plurality of microprism units including 4 or 6 microprisms. Also for example, the microprism array 410 may include a plurality of microprisms distributed in an array.

As another example, a plurality of optical sensing units are disposed below each incident surface of each micro prism in the micro prism array 410. This case may be applied to the micro-prism array 410 composed of micro-prisms having a large size, for example, the micro-prism array 410 includes a plurality of micro-prisms arranged in a first direction, and a plurality of optical sensing units arranged in a second direction is disposed below each incident surface of each of the plurality of micro-prisms, and the first direction is perpendicular to the second direction. In other words, the micro-prism array 410 may include the plurality of micro-prisms distributed in an array, at least one row of the optical sensing units 424 is disposed below each micro-prism of the plurality of micro-prisms, or at least one column of the optical sensing units 424 is disposed below each micro-prism of the plurality of micro-prisms. Alternatively, the plurality of micro prisms may include only one row of micro prisms distributed in an array, and a column of micro lenses is disposed under each micro prism. Alternatively, the plurality of micro prisms may include only one row of micro prisms distributed in an array, and a row of micro lenses is disposed below each micro prism.

For the sake of understanding, the following description will be given taking an example in which a row of microlenses is provided below each microprism.

Fig. 9 is a perspective view of the microprism array 410 of fig. 7. Fig. 10 is a schematic configuration diagram of a fingerprint detection device 40 according to an embodiment of the present application in a plan view. It should be understood that the number of the microprisms and the microlenses shown in the drawings is merely an example for convenience of description, but the present application is not limited thereto.

Referring to fig. 9, the micro-prism array 410 may include only one row of micro-prisms, and a row of micro-lenses may be disposed under each micro-prism. Alternatively, the first micro-prisms 410a, the second micro-prisms 410b, and the third micro-prisms 410c may be stripe structures.

Referring to fig. 10, the micro-prism array 410 may include a first micro-prism 410a and a second micro-prism 410b, wherein a first optical sensing unit 424a and a fourth optical sensing unit 424d are disposed below the first micro-prism 410a, and a second optical sensing unit 424b and a fifth optical sensing unit 424e are disposed below the second micro-prism 410 b. Further, a first micro lens 412a is disposed between the first micro prism 410a and the first optical sensing unit 424a, and a first micro aperture stop 422a is disposed below the first micro lens 412 a. Similarly, a fourth micro-lens 412d is disposed between the first micro-prism 410a and the fourth optical sensing unit 424d, and a fourth micro-aperture stop 422d is disposed below the fourth micro-lens 412 d. A second micro lens 412b is disposed between the second micro prism 410b and the second optical sensing unit 424b, and a second micro aperture 422b is disposed below the second micro lens 412 a. A fifth micro lens 412e is disposed between the second micro prism 410b and the fifth optical sensing unit 424e, and a fifth micro aperture 422e is disposed below the fifth micro lens 412 e. Alternatively, a row of microlenses is disposed below the first microprisms 410a, and a row of microlenses is disposed below the second microprisms 410 b.

And the second optical signal converted by each micro prism is converged by the micro lens corresponding to the same micro prism. Taking the second optical sensing unit 424b as an example, the second micro-prism 410b is configured to convert the first optical signal into a second optical signal, the second micro-lens 412b under the second micro-prism 410b transmits the received second optical signal to the second optical sensing unit 412b through the second micro-aperture 422b corresponding to the second micro-lens 412b, and the fifth micro-lens 412e under the second micro-prism 410b transmits the received second optical signal to the fifth optical sensing unit 412e through the fifth micro-aperture 422e corresponding to the fifth micro-lens 412 e.

Of course, fig. 9 and 10 are merely examples of the present application and should not be construed as limiting the present application.

In other alternative embodiments, for example, the microprism array 410 may comprise a plurality of rows of microprisms with at least one microlens disposed beneath each microprism; for another example, the micro-prism array 410 may include at least one row of micro-prisms, and at least one micro-lens is disposed under each micro-prism.

Fig. 11 is another schematic configuration diagram of a top view of the fingerprint detection device 40 according to the embodiment of the present application. Fig. 12 and 13 are plan views of the microprism unit of fig. 11. It should be understood that the number of microprism units shown in the drawings is merely an example for convenience of description, but the present application is not limited thereto. For convenience of description, the drawings illustrate one microprism unit as an example.

Referring to fig. 11, the fingerprint sensing device 40 may include a plurality of microprism units 810 arranged in an array. The micro prism unit 810 may include a plurality of micro prisms. For example, each of the plurality of microprism units 810 comprises a plurality of microprisms arranged in a central symmetrical distribution. For example, each of the plurality of microprism units 810 may comprise 4 microprisms. Alternatively, each of the plurality of microprism units 810 may include a distribution of microprisms in a polygon, such as a triangle, a quadrangle, a pentagon, a hexagon, or the like, to simplify the arrangement of the photo-sensing unit array 424. The projection area of each micro-prism in the micro-prism unit 810 on the plane where the optical sensing unit array 424 is located may be equal to or approximately equal to the projection area of each micro-lens in the micro-lens array on the plane where the optical sensing unit 424 is located, so as to improve the utilization rate of the micro-prism unit 810 and reduce the volume of the fingerprint detection apparatus 40. Further, one microlens may be disposed under each of the microprisms in each of the microprism units 810. An opening in at least one light blocking layer is arranged below each microlens, and an optical sensing unit is arranged below each opening in the bottom light blocking layer in the at least one light blocking layer.

Among them, one micro-prism unit 810 in the light guiding part 41 and the light detecting part 42 corresponding to the one micro-prism unit 810 may be used to constitute one mother unit of the fingerprint detecting device 40. That is, each mother unit is composed of four sub-units (a sub-unit a, b sub-unit c, and d sub-unit), and includes a first micro-prism 810a, a second micro-prism 810b, a third micro-prism 810c, a fourth micro-prism 810d, and a corresponding light detecting portion 42 therebelow, respectively.

It should be understood that the same reference numerals in fig. 11 as in fig. 7 may be used to designate the same components, and thus, the description thereof will not be repeated herein in order to avoid redundancy.

Referring to fig. 12, each of the plurality of microprism units 810 comprises a plurality of microprisms distributed in a central symmetry. For example, the microprism unit 810 may include a first microprism 810a, a second microprism 810b, a third microprism 810c and a fourth microprism 810d, and the microprism unit 810 composed of the first microprism 810a, the second microprism 810b, the third microprism 810c and the fourth microprism 810d may be a truncated pyramid. For example, the microprism unit 810 consisting of the first microprism 810a, the second microprism 810b, the third microprism 810c and the fourth microprism 810d may be a regular quadrilateral truncated internally tangent pyramid, i.e., the top view of the microprism unit 810 may be an area surrounded by ABCD as shown in fig. 8. Alternatively, the cross-sectional view shown in fig. 12 may be a cross-sectional view in the OA direction of fig. 11.

If a coordinate system with the transverse direction as the X axis and the longitudinal direction as the Y axis is established, the directions of the first microprism 810a, the second microprism 810b, the third microprism 810c and the fourth microprism 810d relative to the origin O are different, for example:

∠AOX＝135°，∠BOX＝45°，∠COX＝-45°，∠DOX＝-135°。

as can be seen, two adjacent microprisms in the microprism unit 810 are different by 90 degrees with respect to the origin O. At this time, the microprism units 810 can be simultaneously used to receive light from four different directions at an incident angle of

The light 831 and 832 in fig. 11 represent two directions thereof, thereby effectively reducing the dependency on the finger placement angle in fingerprint authentication. In particular, due to the microThe prism unit 810 can receive optical signals from a plurality of angles respectively, and converge the optical signals from the plurality of angles to the plurality of optical sensing units through the plurality of microlenses respectively, so that the plurality of optical sensing units below the microprism unit 810 can be divided into a plurality of optical sensing unit groups, the optical signals received by the optical sensing units below the plurality of microprism units 810 belonging to the same optical sensing unit group can be used for generating one fingerprint image, and thus the plurality of optical sensing pixel groups can be used for generating a plurality of fingerprint images.

Therefore, even if the exposure time of the optical sensing unit array 424 is reduced and the resolution of each fingerprint image is low due to the fact that each micro-prism unit 810 receives optical signals of multiple angles, a fingerprint image with high resolution can be obtained by processing multiple fingerprint images with low resolution. That is, the fingerprint detection device 40 not only can ensure fingerprint identification effect, but also can reduce the exposure time of the optical sensing unit array 424 (i.e., image sensor).

Further, by receiving the optical signals of a plurality of angles by each micro-prism unit 810, the field of view of the fingerprint detection device 40 can be increased.

Fig. 14 is a side sectional view of the electronic device with the display screen taken along the direction E-E' shown in fig. 13.

Referring to fig. 14, the electronic device 60 may include a display 61 and a fingerprint detection device 40 under the display, wherein the micro-prism unit in the fingerprint detection device 40 may be used to receive light signals in 4 directions. For example, the third microprism 810c may be configured to receive optical signals in a second direction, i.e., the second field of view shown in the figure may be the field of view of the third microprism 810c, and similarly the first field of view shown in the figure may be the field of view of the first microprism 810 a. I.e. the fingerprint detection device 40 has a field of view in the direction E-E' which is the third field of view shown in the figure, which is larger than the first field of view and larger than the second field of view, effectively increasing the field of view of the fingerprint detection device 40.

It should be understood that fig. 7-13 are only examples of the present application and should not be construed as limiting the present application.

As an example, the number of incidence surfaces of the micro prisms in the micro prism array 410 is not limited in the embodiments of the present application. For example, each of the plurality of microprisms comprises at least one incident surface, and at least one optical sensing unit is arranged under each incident surface of each of the plurality of microprisms; also for example, each of the plurality of microprisms comprises a plurality of entrance facets that are axisymmetric or centrosymmetric.

As another example, the embodiment of the present application does not limit the specific shape of the microprism array 410. For example, each of the plurality of microprisms is a triangular prism or a trapezoidal prism, and for example, each of the plurality of microprisms is a right-angle prism, and an incident surface of each of the plurality of microprisms is an inclined surface of the right-angle prism. For example, each microprism in the array of microprisms 410 can be any of: right angle triangle prism, isosceles triangle prism, right angle trapezoidal prism and isosceles trapezoidal prism.

As still another example, the embodiment of the present application does not limit the specific structure of the optical component. For example, it may be the optical assembly 132 shown in fig. 1 or fig. 2. For example, the optical component can be a device consisting of a micro lens array and a micro-hole diaphragm, and can also be a straight-hole collimator. For example, the straight hole collimator comprises a plurality of straight holes, wherein each optical sensing unit is configured to receive an optical signal transmitted via one or more straight holes. Further, the optical assembly may further include an optical filter.

Fig. 15 is another schematic cross-sectional structural view of the fingerprint detection device 40 according to the embodiment of the present application.

Referring to fig. 15, the optical component is a collimator 911, the collimator 911 may be disposed between the microprism array 410 and the light detecting portion 42, and the collimator 911 may include a plurality of collimators arranged in a certain mannerThe alignment holes 912 are arranged as the only light-transmissive regions in the collimator 911, and each optical sensing unit may correspond to one or more alignment holes 912. For example, each optical sensing unit may correspond to 3 collimating holes 912. Incident angle of

The optical signal reflected by the finger is transmitted to the optical sensor array 424 through the straight hole collimator 911, and then is converted into an electrical signal by the optical sensor array 424. Incident angle of not

The optical signal reflected by the finger is blocked by the straight hole collimator 911, and thus cannot reach the optical sensor array 424. In addition, the straight hole collimator 911 may also transmit the vertical light signal converted by each micro prism to an optical sensing unit under the same micro prism.

Compared with the scheme shown in fig. 6, the microprism array 410 converts the light signal reflected by the finger and inclined relative to the display screen into a signal vertical to the display screen, and then the light signal is screened by the straight-hole collimator 911, so that the manufacturing difficulty and cost of the collimator are effectively reduced.

In addition, since the angular screening capability of the straight hole collimator 911 is mainly determined by the aspect ratio (depth-to-aperture ratio) of the collimating hole 912, the straight hole with small aperture is favorable for improving the image resolution, but reduces the light input amount, so that the exposure time of the photo-sensing unit array 424 needs to be prolonged. A plurality of straight holes are arranged above each photosensitive unit, so that the exposure time of the optical sensing unit array 424 can be effectively reduced, and the user experience is further improved.

It should be understood that fig. 15 is only an example of the present application and should not be construed as limiting the present application.

For example, the optical sensing unit array 424 and the straight hole collimator 911 may be integrated. That is, the straight hole collimator 911 may be integrated in the chip of the light detecting section 92, for example, by forming a collimating hole using a metal layer and a metal via layer in a later process.

It should be understood that the specific examples in the embodiments of the present application are for the purpose of promoting a better understanding of the embodiments of the present application and are not intended to limit the scope of the embodiments of the present application. For example, the fingerprint detection apparatus may further include a fingerprint image processing module, configured to compare and identify the fingerprint image acquired by the optical sensing unit array 424 with a pre-stored fingerprint image. The fingerprint image processing module may be an Application Specific Integrated Circuit (ASIC) chip, a Digital Signal Processing (DSP) chip, or other algorithmic capable chip or module such as an Application Processor (AP).

The embodiment of the application also provides electronic equipment which can comprise a display screen and the fingerprint detection device, wherein the fingerprint detection device is arranged below the display screen to realize optical fingerprint detection 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, such as an OLED display screen or other display screens, and for the description of the display screen, reference may be made to the description of the display screen in the above description, and for brevity, no further description is provided here.

It should be understood that the specific examples in the embodiments of the present application are for the purpose of promoting a better understanding of the embodiments of the present application and are not intended to limit the scope of the embodiments of the present application.

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

Those of ordinary skill in the art will appreciate that the elements of the examples described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the components and steps of the examples have been described above generally in terms of their functionality in order to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the 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.

In the several embodiments provided in the present application, it should be understood that the disclosed system and apparatus may be implemented in other manners. For example, the 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 also be an electric, mechanical or other form of connection.

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 embodiments of the present application.

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 integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially or partially contributed by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes 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 method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

While the invention has been described with reference to specific embodiments, the scope of the invention is not limited thereto, and those skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the invention. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. The utility model provides a fingerprint detection device which characterized in that is applicable to the electronic equipment that has the display screen and in order to realize optical fingerprint detection under the screen, includes:

the micro prism array is arranged below the display screen;

an optical assembly disposed below the microprism array;

2. The fingerprint sensing device of claim 1, wherein each of the microprisms of the array of microprisms comprises at least one entrance surface for receiving the first optical signal and one exit surface for exiting the second optical signal, wherein each of the at least one entrance surface is a plane that is tilted with respect to the display screen and the one exit surface is a plane that is parallel with respect to the display screen.

3. The fingerprint detection device of claim 2, wherein the first light signal forms a first angle with a direction perpendicular to the display screen;

wherein theta represents the second included angle,

4. The fingerprint sensing device of claim 3, wherein the first included angle is greater than or equal to 20 degrees.

5. The fingerprint sensing device according to any one of claims 2 to 4, wherein one optical sensing unit is disposed below each incidence surface of each microprism of the microprism array.

6. The fingerprint sensing device of claim 5, wherein the microprism array comprises a plurality of microprism units distributed in an array, each microprism unit of the plurality of microprism units comprising a plurality of microprisms distributed in central symmetry.

7. The fingerprint sensing device of claim 6, wherein each of the plurality of microprism units comprises 4 microprisms.

8. The fingerprint sensing device of claim 5, wherein the microprism array comprises a plurality of microprisms distributed in an array.

9. The fingerprint detection apparatus of any one of claims 2 to 4, wherein a plurality of optical sensing units are disposed below each incidence surface of each microprism of the microprism array.

10. The fingerprint sensing device of claim 9, wherein the microprism array comprises a plurality of microprisms arranged along a first direction, wherein a plurality of optical sensing elements arranged along a second direction are disposed below each incident surface of each microprism of the plurality of microprisms, and wherein the first direction is perpendicular to the second direction.

11. The fingerprint detection apparatus of any one of claims 1 to 10, wherein each microprism of the array of microprisms is any one of:

12. The fingerprint detection apparatus of any one of claims 1 to 11, wherein the optical assembly comprises:

a micro lens array disposed below the micro prism array;

13. The fingerprint detection device of claim 12, wherein the at least one light blocking layer comprises a bottom light blocking layer disposed at a back focal plane location of the microlens array.

14. The fingerprint sensing device of claim 13, wherein the bottom light blocking layer is a metal wiring layer of the array of optical sensing units.

15. The fingerprint detection apparatus according to any one of claims 12 to 14, wherein the at least one light-blocking layer comprises a plurality of light-blocking layers, and the apertures in each light-blocking layer corresponding to the same microlens are sequentially reduced in aperture from top to bottom.

16. The fingerprint sensing device according to any one of claims 1 to 12, wherein the optical assembly is a straight hole collimator, and each optical sensing unit in the array of optical sensing units corresponds to at least one collimating hole in the straight hole collimator;

the straight hole collimator is used for receiving the second optical signal converted by the microprism array and transmitting the second optical signal to the optical sensing unit array through a collimating hole in the straight hole collimator.

17. The fingerprint sensing device of claim 16, wherein the array of optical sensing units and the straight-hole collimator are integrally disposed.

18. The fingerprint detection apparatus according to any one of claims 1 to 17, further comprising:

the optical filter is arranged at least one of the following positions:

above the microprism array;

between the microprism array and the optical component;

an interior of the optical assembly; and

the optical assembly and the optical sensing unit array.

19. A terminal device, comprising:

a display screen; and

a fingerprint detection device as described in technical feature 1 or 18.