CN109791612B

CN109791612B - Fingerprint identification device and electronic equipment

Info

Publication number: CN109791612B
Application number: CN201880003112.9A
Authority: CN
Inventors: 蒋鹏
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2018-12-26
Filing date: 2018-12-26
Publication date: 2023-08-08
Anticipated expiration: 2038-12-26
Also published as: CN109791612A; WO2020132974A1; WO2020133703A1; CN209640876U

Abstract

The embodiment of the application provides a fingerprint identification device and electronic equipment, this fingerprint identification device includes: the micro telecentric lens array group is used for receiving optical signals formed by reflection of human fingers; the fingerprint sensor is arranged below the micro-telecentric lens array group and is used for imaging based on the optical signals passing through the micro-telecentric lens array group. According to the fingerprint identification device and the electronic equipment, for the scheme of the periodic through hole array, light loss in the vertical direction can be avoided, and then the exposure time of the fingerprint sensor can be reduced. The fingerprint recognition device can also reduce imaging distortion of the whole system relative to the scheme of the micro lens. The fingerprint identification device can improve imaging quality and contrast.

Description

Fingerprint identification device and electronic equipment

Technical Field

The application relates to the technical field of fingerprint identification, in particular to a fingerprint identification device and electronic equipment.

Background

There are two main techniques of the disclosed under-screen optical fingerprint recognition device. The first is an under-screen optical fingerprint identification technology based on a periodic micropore array, the scheme has large light energy loss and long exposure time of the sensor; the other is the under-screen optical fingerprint identification technology based on micro lenses, and the imaging distortion of the fingerprint identification device of the scheme is larger.

Disclosure of Invention

In view of this, the embodiment of the application provides a fingerprint identification device and electronic equipment, and compared with the scheme of periodic through hole array, the light loss in the vertical direction can be avoided, and then the exposure time of the fingerprint sensor can be reduced. The fingerprint recognition device can also reduce imaging distortion of the whole system relative to the scheme of the micro lens. Therefore, the fingerprint identification device of the embodiment of the application greatly improves the imaging quality and contrast of fingerprint identification.

In a first aspect, a fingerprint recognition device is provided, comprising: the micro telecentric lens array group is used for receiving optical signals formed by reflection of human fingers; the fingerprint sensor is arranged below the micro-telecentric lens array group and is used for imaging based on the optical signals passing through the micro-telecentric lens array group.

In one possible implementation, the micro-telecentric lens array group includes: a double telecentric lens array for receiving the optical signal in a vertical direction; the object side telecentric lens array is arranged below the double telecentric lens array and is used for collimating and focusing the optical signals transmitted from the double telecentric lens array and transmitting the optical signals to the fingerprint sensor.

In one possible implementation, the double telecentric lens array includes a plurality of double telecentric lens units including a first microlens, a second microlens, and a first micro aperture stop disposed between the first microlens and the second microlens; and/or the object side telecentric lens array comprises a plurality of object side telecentric lens units, wherein the object side telecentric lens units comprise a third micro lens and a second micro aperture diaphragm arranged below the third micro lens.

In one possible implementation, the first micro-aperture stop is disposed at the confocal plane of the first and second microlenses, and/or the second micro-aperture stop is disposed at the image-side focal plane of the third microlens.

Alternatively, the focal length of the first microlens and the focal length of the second microlens may be the same or different.

In one possible implementation, the diameter of the first micro-aperture diaphragm ranges from 20 μm to 1 μm, and the thickness of the first micro-aperture diaphragm ranges from 100nm to 100 μm; and/or the diameter range of the second micro-aperture diaphragm is 500 nm-20 mu m, and the thickness range of the second micro-aperture diaphragm is 100 nm-100 mu m.

Alternatively, the thickness of the first and/or second aperture stop may be 500nm.

In one possible implementation, the first micro-aperture stop comprises a double-tapered-on-top aperture having a cone angle that is the same as the angle at which the edge rays of the first micro-lens converge, and/or the second micro-aperture stop comprises a single-tapered aperture having a cone angle that is the same as the angle at which the edge rays passing through the third micro-lens converge.

In one possible implementation, the set of micro-telecentric lens arrays comprises spherical microlenses and/or aspherical microlenses.

Optionally, the radius of curvature of the spherical microlenses in the micro-telecentric lens array set ranges from 5 μm to 100 μm. The focal length range of the aspherical microlens in the micro telecentric lens array group is 5-2000 μm.

In one possible implementation, the distance between the double telecentric lens array and the object-side telecentric lens array is less than or equal to 200 μm.

In one possible implementation, one pixel unit of the fingerprint sensor corresponds to at least one micro-telecentric lens group in the micro-telecentric lens array group, for example, if one micro-telecentric lens group includes one double-telecentric lens unit and one object-side telecentric lens unit, one pixel of the fingerprint sensor corresponds to one or more micro-telecentric lens groups composed of one double-telecentric lens unit and one object-side telecentric lens unit.

Alternatively, the object-side telecentric lens units in the object-side telecentric lens array may correspond one-to-one with the pixel units of the fingerprint sensor. The double telecentric lens arrays and the object telecentric lens arrays can be in one-to-one correspondence or not. For example, one double telecentric lens unit may correspond to one or more object-side telecentric lens units, or one object-side telecentric lens unit may correspond to a plurality of double telecentric lens units.

In one possible implementation, the apparatus further includes: the filter plate is arranged above the fingerprint sensor and is used for filtering optical signals formed by reflection of human fingers.

In one possible implementation, when the fingerprint recognition device is applied to an electronic apparatus having a display screen, the fingerprint recognition device is fixed below the display screen with a gap therebetween.

In one possible implementation, the electronic device further includes a middle frame, and the fingerprint recognition device is fixed on the middle frame.

In one possible implementation manner, a foam layer is disposed below the display screen, and the foam layer has an opening at a mounting position of the fingerprint recognition device, so that the fingerprint recognition device can receive an optical signal transmitted from the display screen and formed by reflection of a finger of a human body.

In one possible implementation, the arrangement mode of the micro telecentric lens array group is square or hexagonal.

In one possible implementation, the space between the micro lenses in the micro telecentric lens array set and the micro aperture stops in the micro telecentric lens array set and/or the space between the micro lenses in the micro telecentric lens array set and the micro lenses in the micro telecentric lens array set is filled by any combination of the following transparent media: air, glass and plastic.

For example, the space between the first microlens and the first micro-aperture diaphragm may be filled with air, the space between the first micro-aperture diaphragm and the second microlens may be filled with glass, and the like.

In one possible implementation, the material of the microlenses in the set of micro-telecentric lens arrays is glass or plastic, and/or the microlenses in the set of micro-telecentric lens arrays are implemented by a micro-nano processing process or a compression molding process.

In one possible implementation, the micro-aperture stops in the micro-telecentric lens array set are fabricated by a micro-nano machining process or a nano-printing process.

In a second aspect, there is provided an electronic device comprising a display screen and a fingerprint recognition device in any possible implementation of the first aspect or the first aspect, and the fingerprint recognition device is arranged below the display screen.

In one possible implementation, a gap exists between the fingerprint recognition device and the display screen.

Alternatively, the fingerprint recognition device may be spaced from the display screen by a distance of greater than or equal to 600 μm.

By adopting the telecentric lens, fingerprint collection can be carried out on the area above the telecentric lens, and light in the vertical area above the telecentric lens is focused on the pixel unit of the fingerprint sensor. And by miniaturizing and arraying the telecentric lens, fingerprint imaging within a certain distance can be achieved. Compared with the scheme of the periodic through hole array, the light loss in the vertical direction can be avoided, and the exposure time of the fingerprint sensor can be further reduced. The fingerprint recognition device can also reduce imaging distortion of the whole system relative to the scheme of the micro lens. The fingerprint identification device can achieve higher imaging quality and contrast.

These and other aspects of the present application will be more readily apparent from the following description of the embodiments.

Drawings

Fig. 1 shows a schematic block diagram of an application scenario of an embodiment of the present application.

Fig. 2 is a schematic block diagram of a fingerprint recognition device according to an embodiment of the present application.

Fig. 3 shows an imaging schematic of an object-side telecentric lens.

Fig. 4 shows an imaging schematic of an image-side telecentric lens.

Fig. 5 shows an imaging schematic of a double telecentric lens.

Fig. 6 is a schematic block diagram of a micro-telecentric lens array set in an embodiment of the application.

Fig. 7 shows a schematic structural diagram of a fingerprint recognition device according to an embodiment of the present application.

Fig. 8 is an assembly structure diagram of the fingerprint recognition device of the embodiment of the present application.

Fig. 9 is a schematic block diagram of an electronic device of an embodiment of the present application.

Detailed Description

In order to better understand the technical solutions in the embodiments of the present application, the following description will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in this application shall fall within the scope of protection of the embodiments in this application.

The fingerprint identification device provided by the embodiment of the application can be applied to smart phones, tablet computers and other mobile terminals or other terminal devices with display screens; more specifically, in the above terminal device, the fingerprint recognition device may be embodied as an optical fingerprint device, which may be disposed in a partial area or a whole area Under the display screen to form an Under-screen (Under-display) optical fingerprint system.

As shown in fig. 1, which is a schematic structural diagram of a terminal device to which the embodiments of the present application may be applied, the terminal device 100 includes a display screen 120 and a fingerprint recognition device 130, where the fingerprint recognition device 130 is disposed in a local area below the display screen 120. The fingerprint recognition device 130 may include an induction array having a plurality of optical induction units, wherein the induction array may also be a fingerprint sensor. The area where the sensing array is located or the optical sensing area thereof is the fingerprint detection area 103 of the fingerprint identification device 130. As shown in fig. 1, the fingerprint detection area 103 is located in the display area 102 of the display screen 120, so that when a user needs to unlock the terminal device 100 or perform other fingerprint verification, the user can input a fingerprint by pressing a finger against the fingerprint detection area 103 located in the display screen 120. Since fingerprint detection can be implemented in the screen, the terminal device 100 adopting the above structure does not need a special reserved space on the front surface thereof to set fingerprint keys (such as Home keys).

As a preferred embodiment, the display 120 may be a display having a self-luminous display unit, such as an Organic Light-Emitting Diode (OLED) display or a Micro-LED (Micro-LED) display. In addition, the display screen 120 may be specifically a touch display screen, which may not only perform screen display, but also detect a touch or press operation of a user, so as to provide a personal computer interaction interface for the user. For example, in one embodiment, the terminal device 100 may include a touch controller, which may be specifically a touch panel, which may be disposed on the surface of the display screen 120, or may be partially integrated or integrally integrated into the display screen 120, so as to form the touch display screen. Taking an OLED display as an example, the fingerprint recognition device 130 may use a display unit (i.e., an OLED light source) of the OLED display 120 located in the fingerprint detection area 103 as an excitation light source for optical fingerprint detection.

In other embodiments, the fingerprint recognition device 130 may also use an internal light source or an external light source to provide an optical signal for fingerprint detection. In this case, the fingerprint recognition device 130 may be adapted to a non-self-luminous display screen, such as a liquid crystal display screen or other passive light emitting display screen. Taking the application to a liquid crystal display with a backlight module and a liquid crystal panel as an example, in order to support the under-screen fingerprint detection of the liquid crystal display, the fingerprint recognition device 130 may further include an excitation light source for optical fingerprint detection, where the excitation light source may be specifically an infrared light source or a light source of non-visible light with a specific wavelength, which may be disposed below the backlight module of the liquid crystal display or an edge area below a protective cover plate of the terminal device 100, and the fingerprint recognition device 130 is disposed below the backlight module, and the backlight module performs an opening or other optical design on a film layer such as a diffusion sheet, a brightness enhancing sheet, a reflective sheet, etc. to allow fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach an induction array of the fingerprint recognition device 130.

Moreover, the sensing array of the fingerprint recognition device 130 may be a Photo detector (Photo detector) array, which includes a plurality of Photo detectors distributed in an array, and the Photo detectors may be used as the optical sensing units as described above. When a finger is pressed against the fingerprint detection area 103, light rays emitted by a display unit of the fingerprint detection area 103 reflect on a fingerprint on the surface of the finger to form reflected light, wherein the reflected light rays of ridges and valleys of the fingerprint of the finger are different, and the reflected light rays penetrate through the display screen 120 and are received by the photodetector array and are converted into corresponding electric signals, namely fingerprint detection signals; fingerprint image data can be obtained based on the fingerprint detection signal, and fingerprint matching verification can be further performed, thereby realizing an optical fingerprint recognition function at the terminal device 100.

In other alternative embodiments, the fingerprint recognition device 130 may be disposed in the entire area under the display screen 120, so as to extend the fingerprint detection area 103 to the entire display area 102 of the entire display screen 120, thereby implementing full-screen fingerprint recognition.

It should be understood that in a specific implementation, the terminal device 100 may further include a transparent protective cover plate 110, where the cover plate 110 may be a glass cover plate or a sapphire cover plate, and is disposed above the display screen 120 and covers the front surface of the terminal device 100. Thus, in the embodiment of the present application, the pressing of the display screen 120 by a finger actually means pressing the cover plate 110 above the display screen 120 or covering the surface of the protective layer of the cover plate 110.

As an alternative implementation, as shown in fig. 1, the fingerprint recognition device 130 may include a light detection portion 134 and an optical component 132, where the light detection portion 134 includes the sensing array and a reading circuit and other auxiliary circuits electrically connected to the sensing array, which may be fabricated on one chip (Die) by a semiconductor process; i.e. the light detecting section 134 may be fabricated on an optical imaging chip or an image sensing chip.

The optical assembly 132 may be disposed over the sensing array of the light detecting portion 134, and the optical assembly 132 may include a Filter layer (Filter), a light guiding layer, and other optical elements; the filter layer may be used to filter out ambient light that penetrates the finger, and the light guide layer is mainly used to guide (e.g. optically collimate or converge) the reflected light reflected from the finger surface to the sensing array for optical detection.

The light emitted by the display screen 120 is reflected on the surface of the finger to be detected above the display screen 120, and after the reflected light reflected from the finger is optically collimated or converged by the micropore array or the lens unit, the reflected light is further filtered by the filter layer and then received by the optical detection portion 134, and the optical detection portion 134 can further detect the received reflected light, so as to obtain a fingerprint image of the finger to realize fingerprint identification.

It should be appreciated that the fingerprint recognition device 130 is merely an exemplary structure, and in a specific implementation, the position of the filter layer of the optical component 132 is not limited to the position below the light guiding layer; for example, in an alternative embodiment, the filter layer may also be disposed between the light guiding layer and the display screen 120, i.e. above the light guiding layer; alternatively, the optical component 132 may include two filter layers disposed above and below the light guide layer, respectively. In other alternative embodiments, the filter layer may be integrated into the light guiding layer, or may be omitted, which is not limited in this application.

In a specific implementation, the optical component 132 may be packaged in the same optical fingerprint chip as the light detecting portion 134. The optical component 132 may be mounted inside the fingerprint recognition device as a component independent of the optical detection portion 134, that is, the optical component 132 may be disposed outside the chip where the optical detection portion 134 is located, for example, the optical component 132 may be attached to the chip, or a part of the components of the optical component 132 may be integrated into the chip. There are various implementations of the light guiding layer of the optical component 132.

In one embodiment, the light guiding layer of the optical component 132 is specifically a light path modulator or a light path collimator fabricated on a semiconductor silicon wafer or other substrate (such as silicon oxide or nitride), which has a plurality of light path modulating units or collimating units, and in particular, the light path modulating units or the collimating units may be specifically through holes with high aspect ratio, so that the plurality of collimating units or the lens units may form a through hole array. Among the reflected light reflected from the finger, the light incident to the light path modulation unit or the collimation unit can pass through and be received by the optical sensing units below the light path modulation unit or the collimation unit, and each optical sensing unit can basically receive the reflected light of the fingerprint lines guided by the through holes above the optical sensing units, so that the sensing array can detect the fingerprint image of the finger.

In other alternative embodiments, the light guiding layer may also comprise an optical Lens (Lens) layer having one or more optical Lens elements, such as a Lens group of one or more aspherical microlenses. After the reflected light reflected from the finger is collimated or converged by the optical lens unit, the reflected light is received by the optical sensing unit below the optical lens unit, so that the sensing array can detect the fingerprint image of the finger.

On the other hand, the sensor Array of the light detecting section 134 may specifically include only a single sensor Array, or may be a Dual sensor Array (Dual Array) or Multiple sensor Array (Multiple Array) structure having two or more sensor arrays arranged side by side. When the light detecting section 134 adopts a dual-sensor array or multi-sensor array architecture, the optical component 132 can adopt a single light guiding layer to cover the two or more sensor arrays simultaneously; alternatively, the optical component 132 may also include two or more light guiding layers disposed side by side, such as two or more light path modulators or light path collimators, or two or more optical lens layers, respectively disposed above the two or more sensing arrays correspondingly for guiding or converging the Guan Fanshe light to the sensing arrays below.

In other alternative implementations, the display 120 may also be a non-self-luminous display, such as a liquid crystal display using a backlight; in this case, the fingerprint recognition device 130 cannot use the display unit of the display screen 120 as the excitation light source, so that the excitation light source needs to be integrated inside the fingerprint recognition device 130 or provided outside thereof to implement optical fingerprint detection, and the detection principle is consistent with that described above.

It should be appreciated that although the fingerprint recognition device is exemplified as an off-screen optical fingerprint recognition device in the embodiment shown in fig. 1, in other embodiments, the fingerprint recognition device of the terminal device 100 may be replaced by an ultrasonic fingerprint recognition device or other types of fingerprint recognition devices. The type and specific structure of the fingerprint identification device are not particularly limited, and the fingerprint identification device can meet the performance requirement of fingerprint identification in the display screen of the terminal equipment.

In one implementation, the fingerprint recognition device 130 may employ a periodic array of micro-holes to transmit light to the sensing array, which results in a large loss of light energy and a long sensor exposure time.

In another implementation, the fingerprint recognition device 130 may use a micro lens to transmit light to the sensing array, and because a common lens is used, when the object distance is changed during the imaging process, the size of the image will be changed correspondingly, which may result in the same focal lens, corresponding to different object distances, with different magnification. In addition, the common lens has a certain range of depth of field, and when the measured object is not in the range of depth of field of the lens, the image becomes blurred and cannot be focused clearly. Resulting in poor fingerprint recognition accuracy.

In order to solve the above-mentioned various problems, embodiments of the present application provide a new fingerprint recognition device that may be disposed below a display screen. Specifically, as shown in fig. 2, the fingerprint recognition device 200 may include a micro-telecentric lens array set 210 and a fingerprint sensor 220, and the micro-telecentric lens array set 210 may be disposed above the fingerprint sensor 220. The micro telecentric lens array 210 is used for receiving the light signal which is formed by reflection of the finger of the human body and is in the vertical direction, and further, the light signal is collimated and focused. The fingerprint sensor 220 is configured to image based on the optical signals passing through the set of micro-telecentric lens arrays 210.

For ease of understanding, a brief description of a telecentric lens is first provided.

Telecentric lens is essentially a combination of a common lens and aperture imaging principles. The method can ensure that the obtained image magnification does not change within a certain object distance range, does not change along with the change of depth of field, has no parallax, and can improve the fingerprint identification precision when being applied to the fingerprint identification technology.

In general, telecentric lenses can be further classified into object-side telecentric lenses, image-side telecentric lenses, and double telecentric lenses. The principles of various telecentric lenses are described below in connection with fig. 3-5.

Fig. 3 shows the imaging principle of an object-side telecentric lens. As shown in fig. 3, an aperture stop is placed at the focal plane of the image side of the common lens, and the aperture stop is used for enabling only the parallel incident object side rays (such as ray 1 and ray 2) to reach the image plane for imaging, so that the geometric relationship can be seen that the image is not in a relationship of near-large and far-small. That is, it corresponds to an object at infinity.

Fig. 4 illustrates the imaging principle of an image-side telecentric lens. As shown in fig. 4, an aperture stop is placed at the object-side focal plane of the normal lens, so that the principal rays (such as ray 1 and ray 2) of the image side are parallel to the optical axis, and the magnification of the telecentric lens of the image side is independent of the image distance.

Fig. 5 illustrates the imaging principle of a double telecentric lens. As shown in fig. 5, the double telecentric lens combines the advantages of both an object-side telecentric lens and an image-side telecentric lens. The lens consists of two groups of lenses (such as a lens 1 and a lens 2), and an aperture diaphragm is arranged at the confocal surface of the two groups of lenses, so that the principal rays (such as a ray 1 and a ray 2) of the lens are parallel to an optical axis at both an object space and an image space.

Because a single telecentric lens is typically required for imaging with a relatively large imaging surface, the entire lens group can be relatively thick. However, after the telecentric lens is miniaturized in an array mode, objects with a certain distance can be imaged, so that the telecentric lens can be applied to fingerprint identification technology. The telecentric lens after the arrayed miniaturization constitutes the micro telecentric lens array group 210 in the fingerprint recognition device 200 provided in the embodiment of the present application.

The micro telecentric lens array group, as the name implies, may be a combination of various arrayed miniaturized telecentric lens units. For example, as shown in fig. 6, the micro-telecentric lens array set 210 may include a double telecentric lens array 211 and an object telecentric lens array 212, and the object telecentric lens array 212 may be disposed below the double telecentric lens array 211, wherein the double telecentric lens array 211 mainly receives light signals formed by reflection of human fingers and receives light signals of small angles in the vertical direction; the object-side telecentric lens array 212 is used for collimating and focusing the optical signals transmitted from the double telecentric lens array 211, and the sensing array of the fingerprint sensor 220 can receive the optical signals transmitted from the object-side telecentric lens array 212 and image based on the optical signals.

In the present embodiment, the double telecentric lens array 211 and the object telecentric lens array 212 are also telecentric lenses after miniaturization. The double telecentric lens array 211 may be constituted by a plurality of double telecentric lens units, and as shown in fig. 5, one double telecentric lens unit is constituted by two microlenses and one micro aperture stop, wherein the micro aperture stop may be disposed between the two microlenses. The object-side telecentric lens array 212 may be composed of a plurality of object-side telecentric lens units, and as shown in fig. 3, an object-side telecentric lens is composed of a microlens and a micro-aperture diaphragm, wherein the micro-aperture diaphragm may be disposed on the side of the microlens that images. That is, the optical signal reflected by the finger needs to pass through the microlens array 1, the micro aperture stop array 1, the microlens array 2, the microlens array 3, and the micro aperture stop array 2 in this order as shown in fig. 7 after passing through the display screen, so as to reach the fingerprint sensor. Wherein microlens array 1, micro aperture stop array 1, and microlens array 2 form a double telecentric lens array 211, while microlens array 3 and micro aperture stop array 2 form an object telecentric lens array 212.

Alternatively, the micro-telecentric lens array set 210 may also be provided with only one micro-aperture stop array below the double telecentric lens array. That is, the optical signal formed by the reflection of the finger may sequentially pass through the micro lens array 1, the micro aperture stop array 1, the micro lens array 2 or the micro lens array 3, and the micro aperture stop array 2 as shown in fig. 7 after passing through the display screen, and then reach the fingerprint sensor. The micro lens array 1, the micro aperture diaphragm array 1 and the micro lens array 2 form a double telecentric lens array 211, and the double telecentric lens array is used for receiving light signals formed by fingerprint reflection in the vertical direction, and the micro aperture diaphragm array 2 is used for converging light transmitted by the double telecentric lens array and transmitting the light to the fingerprint sensor.

It should be understood that in the fingerprint recognition device provided in the embodiment of the present application, the fingerprint recognition device is composed of a micro-telecentric lens array group and a fingerprint sensor, and the micro-telecentric lens array group is mainly composed of a micro-lens array and a micro-aperture diaphragm array. As to how this is achieved in connection with the three telecentric lenses of fig. 3 to 5, no particular limitation is made here.

Alternatively, in the embodiments of the present application, the space between the micro lens and the micro aperture stop and/or the space between the micro lens and the micro lens is filled with air, glass, plastic or any other transparent material, or any combination of the above transparent materials. For example, the filling between the microlens array 1 and the micro aperture stop array 1, between the micro aperture stop array 1 and the microlens array 2, between the microlens array 2 and the microlens array 3, and between the microlens array 3 and the micro aperture stop array 2 in fig. 7 may be the same or different. For example, it may be all air, glass or plastic, etc. Or may be a different filling between the micro lenses and the micro aperture stop than between the micro lenses and the micro lenses. For example, air-packing may be provided between the microlens and the micro aperture stop, and glass-packing may be provided between the microlens and the microlens, which is not limiting in this application.

Alternatively, the micro lens in the embodiment of the application may be implemented by a micro-nano processing process or a press molding process, and the micro-aperture diaphragm in the embodiment of the application may be manufactured by a micro-nano processing process or a nano printing process, so as to implement miniaturized array of the telecentric lens.

One skilled in the art will appreciate that a double telecentric lens unit is comprised of two microlenses and a micro aperture stop, and an object side telecentric lens unit is comprised of one microlens and a micro aperture stop. And a micro-aperture stop in the double telecentric lens unit may be disposed at the confocal planes of the two microlenses. That is, the focal points of the two microlenses overlap, and an aperture stop is inserted at the overlapping focal points, thereby forming a double telecentric lens unit. The micro-aperture stop in the object-side telecentric lens unit is disposed at the image-side focal plane of the microlens. The focal lengths of the two microlenses in the double telecentric lens unit may be the same or different, and if the focal lengths are the same, the two microlenses may be symmetrical with respect to the confocal plane, that is, with respect to the micro aperture stop. If the focal lengths of the two microlenses are different, the two microlenses may be asymmetric with respect to the common focal plane. In other words, the two microlenses are no longer centered on the micro-aperture stop.

Alternatively, in the embodiment of the present application, the micro aperture stop in the double telecentric lens unit and the micro aperture stop in the object telecentric lens unit may have a certain thickness, and then the micro aperture stop may be a cylindrical hole or not. For example, the micro-aperture stop in the double telecentric lens unit may be a biconical aperture at the vertex and the micro-aperture stop in the object-side telecentric lens array may be a biconical aperture. And the cone angle of the pair of top biconic holes and the single conical hole may be the same as the converged angle of the edge light rays passing through the microlens thereabove. It should be understood that the double tapered holes or the single tapered holes may be conical or triangular, and are not limited herein.

In addition, the thickness of the micro aperture stop is not particularly limited in the embodiment of the present application, as long as the thickness is smaller than the distance between the micro aperture stop and the microlens.

Alternatively, in the embodiment of the present application, one micro-telecentric lens group of the micro-telecentric lens array groups may correspond to one pixel unit of the fingerprint sensor. Wherein the one micro-telecentric lens group may include one double-telecentric lens unit and one object-side telecentric lens unit. Specifically, the object-side telecentric lens units in the object-side telecentric lens array may correspond to the pixel units of the fingerprint sensor one by one. The double telecentric lens arrays and the object telecentric lens arrays can be in one-to-one correspondence or not. For example, one double telecentric lens unit may correspond to one or more object-side telecentric lens units, or one object-side telecentric lens unit may correspond to a plurality of double telecentric lens units.

Alternatively, one of the groups of micro-telecentric lens arrays may be corresponded to a plurality of pixel units of the fingerprint sensor. For example, one object-side telecentric lens in the array of object-side telecentric lenses may be associated with four pixel units. In other words, the pixel density of the fingerprint sensor may be doubled or higher, or the pixel unit of the fingerprint sensor may be smaller than the period of the telecentric lens unit.

For an arrayed telecentric lens, a single pixel period is required to be related to the resolution requirement of an object, for example, a fingerprint identification device arranged under a display screen, and the pixel period of the telecentric lens can be set to be 25 μm in sampling rate along the X/Y direction of the plane of the display screen.

The fingerprint identification device provided by the embodiment of the application adopts the telecentric lens, can collect fingerprints in the area above the telecentric lens, and focuses light in the vertical area above the telecentric lens to the pixel unit of the fingerprint sensor. And by miniaturizing and arraying the telecentric lens, fingerprint imaging within a certain distance can be achieved. Compared with the scheme of the periodic through hole array, the light loss in the vertical direction can be avoided, and the exposure time of the fingerprint sensor can be further reduced. Compared with the scheme of micro lenses, the fingerprint identification device can reduce imaging distortion of the whole system, and can achieve higher imaging quality and contrast.

Alternatively, in the embodiment of the present application, for a double telecentric lens, the diameter of the micro aperture stop may range from 20 μm to 1 μm, and the thickness of the micro aperture stop may range from 100nm to 100 μm, for example, the thickness may be 500nm. For an object side telecentric lens, the diameter of the micro aperture diaphragm ranges from 500nm to 20 mu m, and the thickness of the micro aperture diaphragm can range from 100nm to 100 mu m. Alternatively, the surface type of each microlens in the telecentric lens may be spherical or aspherical, that is, the surface type of the microlens in the telecentric lens group composed of one double telecentric lens unit and one object telecentric lens unit may be all spherical or aspherical, or one of them may be spherical or aspherical. Alternatively, the radius of curvature of the spherical microlenses may be a value between 5 μm and 100 μm. While the radius of curvature of the aspherical microlens varies with the central axis. Alternatively, the focal length range of the aspherical microlens may be a certain value between 5 μm and 2000 μm, and in particular, may be a certain value between 5 μm and 500 μm.

Alternatively, the distance between the double telecentric lens array and the object telecentric lens array may be less than or equal to 200 μm. For example, the particle size may be 1 μm to 200. Mu.m. Specifically, the distance between the double telecentric lens array and the object telecentric lens array can be set to be less than 50 μm.

Optionally, in the embodiment of the present application, the material of the micro-telecentric lens array set may be glass, plastic, or other transparent materials. The arrangement of the micro telecentric lens array group may be square, for example, square or rectangle, or hexagonal, or any other form, which is not limited in the embodiment of the present application.

Optionally, as shown in fig. 7, the fingerprint recognition device 200 of the embodiment of the present application may further include a filter for filtering the optical signal reflected by the finger. The filter may be between the display screen and the fingerprint sensor, for example, between the fingerprint sensor and the array of micro-telecentric lenses. It should be understood that, in a specific implementation, the position of the filter is not limited to the position below the micro-telecentric lens array set, but may be disposed between the micro-telecentric lens array set and the display screen, i.e., above the micro-telecentric lens array set; alternatively, two layers of filters may be included, disposed above and below the array of micro-telecentric lenses, respectively. In other alternative embodiments, the filter may be disposed inside the group of micro-telecentric lens arrays, for example, between the double-telecentric lens array and the object-side telecentric lens array, or may be omitted, which is not limited in this application.

It will be appreciated that the filter may be used to reduce unwanted background light in fingerprint sensing to enhance the optical sensing of received light by the fingerprint sensor. The filter may be used in particular to filter out ambient light wavelengths, e.g. near infrared light and part of red light, etc. As another example, blue light or a portion of blue light. For example, if a human finger absorbs a substantial portion of the energy of light having a wavelength below 580nm, if one or more optical filters or optical filter coatings can be designed to filter light having wavelengths from 580nm to infrared, the effect of ambient light on optical detection in fingerprint sensing can be greatly reduced.

Alternatively, the filter may be an infrared cut-off optical filter.

Fig. 8 shows a schematic structural diagram of a fingerprint identification apparatus provided in an embodiment of the present application. When the fingerprint recognition device is applied to an electronic apparatus (e.g., a smart phone), as shown in fig. 8, the lower surface of the protective cover 310 is attached to the upper surface of the display screen 320, the fingerprint recognition device 330 may be fixedly disposed below the display screen 320, and the lower surface of the fingerprint recognition device 330 is welded to the flexible circuit board 350. And a gap 390 exists between the fingerprint recognition device 330 and the display screen 320. As an alternative implementation manner, the fingerprint recognition device 330 may be mounted below the display screen 320 by being fixedly connected to a device that is easily detachable inside the terminal device, for example, the fingerprint recognition device 330 may be mounted on a lower surface of the middle frame 370, the middle frame 370 may be used as a fixing frame between the fingerprint recognition device 330 and the display screen 320, and an upper surface of the middle frame 370 may be attached to an edge portion of the lower surface of the display screen 320 through a foam back glue 360. The center frame 370 is disposed intermediate the display screen 320 and the rear cover and is used to carry the frame of various internal components including, but not limited to, batteries, motherboards, cameras, cables, various sensors, microphones, headphones, and the like. Thus, the fingerprint recognition device 330 and the display screen 320 are completely decoupled, and damage to the display screen 320 when the fingerprint recognition device 330 is mounted or dismounted is avoided.

Alternatively, the fingerprint recognition device 330 may be installed between the display screen 320 and the middle frame 370 with a gap from the display screen 320. For example, the fingerprint recognition device 330 may be mounted on the upper surface of the middle frame 370. Therefore, various parts in the electronic equipment do not need to be avoided, for example, the fingerprint identification device and the battery can be overlapped in the thickness direction of the electronic equipment, so that the placement position of the fingerprint identification device is not limited.

Alternatively, the fingerprint recognition device 330 may be spaced from the underside of the display screen 320 by a distance greater than or equal to 600 μm. The safety distance between the fingerprint recognition device 330 and the display screen 320 is satisfied, and the loss of devices caused by vibration or falling is avoided.

The middle frame 370 may be made of metal or alloy material, or even plastic material, in which case the middle frame 370 may be formed integrally with the frame of the electronic device, i.e., the inner middle frame and the frame are integrally formed. For example, the frame may be a metal welt only, or a metal-like coating may be applied to the center. Further, the middle frame 370 may be a composite middle frame, for example, the mobile phone, where the middle frame 370 includes an inner middle frame 1 and an outer middle frame 2, the inner middle frame 1 is used for carrying mobile phone components, the outer middle frame 2 is outside the inner middle frame 1, the outer edge of the outer middle frame 2 is provided with mobile phone keys, and the inner middle frame 1 and the outer middle frame 2 are integrated into a whole. The mobile phone middle frame is designed into the inner middle frame and the outer middle frame, the inner middle frame and the outer middle frame are integrated into a whole, when the mobile phone is impacted, the outer middle frame is firstly worn, and the outer middle frame is replaced simply and conveniently due to the fact that only keys are arranged on the outer middle frame, and the cost is low; further, an elastic material can be arranged between the inner middle frame and the outer middle frame, and the inner middle frame and the outer middle frame are relatively fixed under the compression of the elastic force of the elastic layer, so that the elastic layer can reduce the impact on the inner middle frame when the outer middle frame bears the impact force.

Optionally, a layer of foam may be disposed below the display screen 320, and a sealed environment may be formed between the lower side of the display screen 320 and the fingerprint recognition device 330, so as to meet the requirements of light shielding and dust prevention. And the foam layer may be perforated at the installation location of the fingerprint recognition device 330 so that the fingerprint recognition device 330 can receive the light signal transmitted through the display screen 320. When a finger is placed over the illuminated display screen 320, the finger reflects light from the display screen 320, which reflected light passes through the display screen. A fingerprint is a diffuse reflector whose reflected light exists in all directions. By using a specific light path, the fingerprint sensor only receives light in the vertical direction, and the fingerprint can be calculated through an algorithm.

The embodiment of the application also provides electronic equipment, which comprises the fingerprint identification device and the display screen in the various embodiments, wherein the fingerprint identification device is positioned below the display screen. Further, the electronic device further comprises a middle frame, and the fingerprint identification device can be fixed on the middle frame.

Fig. 9 is a schematic block diagram of an electronic device 400 provided in accordance with an embodiment of the present application. The electronic device 400 shown in fig. 9 includes: radio Frequency (RF) circuitry 410, memory 420, other input devices 430, a display 440, sensors 450, audio circuitry 460, I/O subsystem 470, processor 480, and power supply 490. It will be appreciated by those skilled in the art that the electronic device structure shown in fig. 7 is not limiting of the electronic device and may include more or fewer components than shown, or may combine certain components, or split certain components, or a different arrangement of components. Those skilled in the art will appreciate that the display 440 pertains to a User Interface (UI), and that the electronic device 400 may include fewer User interfaces than illustrated or otherwise.

The following describes the respective constituent elements of the electronic device 400 in detail with reference to fig. 9:

the RF circuit 410 may be used for receiving and transmitting signals during the process of receiving and transmitting information or communication, in particular, after receiving downlink information of the base station, the downlink information is processed by the processor 480; in addition, the data of the design uplink is sent to the base station. Typically, RF circuitry includes, but is not limited to, antennas, at least one amplifier, transceivers, couplers, low noise amplifiers (Low Noise Amplifier, LNAs), diplexers, and the like. In addition, the RF circuitry 410 may also communicate with networks and other devices via wireless communications. The memory 420 may be used to store software programs and modules that the processor 480 performs various functional applications and data processing of the electronic device 400 by executing the software programs and modules stored in the memory 420. The memory 420 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program (such as a sound playing function, an image playing function, etc.) required for at least one function, and the like; the storage data area may store data created according to the use of the electronic device 400 (such as audio data, phonebooks, etc.), and the like. In addition, memory 420 may include high-speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid-state storage device.

Other input devices 430 may be used to receive entered numeric or character information and to generate signal inputs related to user settings and function control of electronic device 400. In particular, other input devices 430 may include, but are not limited to, one or more of a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, a joystick, a light mouse (a light mouse is a touch-sensitive surface that does not display visual output, or an extension of a touch-sensitive surface formed by a screen), etc. The other input devices 430 are connected to other input device controllers 471 of the I/O subsystem 470 and are in signal communication with the processor 480 under control of the other input device controllers 471.

The display 440 may be used to display information entered by a user or provided to a user as well as various menus of the electronic device 400, and may also accept user inputs. The display 440 may be a touch screen, and may include a display panel 441 and a touch panel 442. The touch panel 442 may overlay the display panel 441 and a user may operate on or near the touch panel 442 overlaid on the display panel 441 based on what the display panel 441 displays (including, but not limited to, soft keyboards, virtual mice, virtual keys, icons, etc.), after the touch panel 442 detects an operation thereon or thereanear, it is passed to the processor 480 via the I/O subsystem 470 to determine user input, and the processor 480 then provides a corresponding visual output on the display panel 441 via the I/O subsystem 470 based on the user input. Although in fig. 8, the touch panel 442 and the display panel 441 are two separate components to implement the input and input functions of the electronic device 400, in some embodiments, the touch panel 442 and the display panel 441 may be integrated to implement the input and output functions of the electronic device 400.

The electronic device 400 may further comprise at least one sensor 450, for example, the sensor 450 may be a fingerprint sensor located under the display 440 or within the display 440, i.e. a fingerprint recognition device in embodiments of the present application.

Audio circuitry 460, speaker 461, microphone 462 can provide an audio interface between a user and electronic device 400. The audio circuit 460 may transmit the received audio data converted signal to the speaker 461, and the audio data is converted into a sound signal by the speaker 461 to be output; on the other hand, microphone 462 converts the collected sound signals into signals, which are received by audio circuit 460 and converted into audio data, which are output to RF circuit 410 for transmission to, for example, another cell phone, or to memory 420 for further processing.

The I/O subsystem 470 is used to control input and output external devices, which may include other device input controllers 471, sensor controllers 472, display controllers 473. Optionally, one or more other input control device controllers 471 receive signals from other input devices 430 and/or send signals to other input devices 430, and other input devices 430 may include physical buttons (push buttons, rocker buttons, etc.), dials, slide switches, joysticks, click wheels, optical mice (optical mice are touch-sensitive surfaces that do not display visual output, or are extensions of a touch-sensitive surface formed by a screen). It should be noted that other input control device controllers 471 may be connected to any one or more of the above devices. The display controller 473 in the I/O subsystem 470 receives signals from the display screen 440 and/or transmits signals to the display screen 440. After the display screen 440 detects a user input, the display controller 473 converts the detected user input into an interaction with the user interface object displayed on the display screen 440, i.e., a man-machine interaction is realized. Sensor controller 472 can receive signals from one or more sensors 440 and/or transmit signals to one or more sensors 440.

Processor 480 is a control center of electronic device 400 that utilizes various interfaces and lines to connect various portions of the overall electronic device, perform various functions of electronic device 400, and process data by running or executing software programs and/or modules stored in memory 420, and invoking data stored in memory 420, thereby performing overall monitoring of the electronic device. Optionally, the processor 480 may include one or more processing units; preferably, the processor 480 may integrate an application processor that primarily handles operating systems, user interfaces, applications, etc., with a modem processor that primarily handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 480. The processor 480 may be configured to perform various steps in method embodiments of the present application.

The electronic device 400 also includes a power supply 490 (e.g., a battery) for powering the various components, which may be logically connected to the processor 480 via a power management system so as to perform functions such as managing charge, discharge, and power consumption via the power management system.

Although not shown, the electronic device 400 may further include a camera, a bluetooth module, etc., which will not be described herein.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

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

In several embodiments provided herein, it should be understood that the disclosed circuits, branches, and units may be implemented in other ways. For example, the branches described above are schematic, for example, the division of the unit is merely a logic function division, and there may be another division manner in actual implementation, for example, multiple units or components may be combined or may be integrated into one branch, or some features may be omitted or not performed.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in 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 (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

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

Claims

1. A fingerprint recognition device applied to an electronic apparatus having a self-luminous display screen, comprising:

the micro telecentric lens array group is used for receiving optical signals formed by reflection of human fingers;

the fingerprint sensor is arranged below the micro-telecentric lens array group and is used for imaging based on the optical signals passing through the micro-telecentric lens array group;

the micro telecentric lens array group comprises:

a double telecentric lens array for receiving the optical signal in a vertical direction;

the object side telecentric lens array is arranged below the double telecentric lens array and is used for collimating and focusing the optical signals transmitted from the double telecentric lens array and transmitting the optical signals to the fingerprint sensor.

2. The apparatus of claim 1, wherein the double telecentric lens array comprises a plurality of double telecentric lens units comprising a first microlens, a second microlens, and a first micro aperture stop disposed between the first microlens and the second microlens; and/or

The object side telecentric lens array comprises a plurality of object side telecentric lens units, wherein each object side telecentric lens unit comprises a third micro lens and a second micro aperture diaphragm arranged below the third micro lens.

3. The device of claim 2, wherein the first micro-aperture stop is disposed at a confocal plane of the first and second microlenses, and/or the second micro-aperture stop is disposed at an image-side focal plane of the third microlens.

4. The apparatus of claim 2, wherein the focal lengths of the first and second microlenses are the same or different.

5. The device according to claim 2, wherein the diameter of the first micro-aperture diaphragm ranges from 20 μm to 1 μm, and the thickness of the first micro-aperture diaphragm ranges from 100nm to 100 μm; and/or the diameter range of the second micro-aperture diaphragm is 500 nm-20 mu m, and the thickness range of the second micro-aperture diaphragm is 100 nm-100 mu m.

6. The apparatus of claim 2, wherein the first micro-aperture stop comprises a double-tapered, opposite-top aperture having a cone angle that is the same as the angle at which the edge rays of the first micro-lens converge, and/or the second micro-aperture stop comprises a single-tapered aperture having a cone angle that is the same as the angle at which the edge rays passing through the third micro-lens converge.

7. The apparatus of claim 1, wherein a distance between the double telecentric lens array and the object telecentric lens array is less than or equal to 200 μιη.

8. The apparatus of claim 1, wherein between the microlenses in the set of micro-telecentric lens arrays and the micro-aperture stops in the set of micro-telecentric lens arrays and/or between the microlenses in the set of micro-telecentric lens arrays and the microlenses in the set of micro-telecentric lens arrays are filled by any combination of the following transparent media: air, glass and plastic.

9. The apparatus of claim 1, the set of micro-telecentric lens arrays comprising spherical microlenses and/or aspherical microlenses.

10. The apparatus of claim 1, wherein the spherical microlenses in the array of micro-telecentric lenses have a radius of curvature ranging from 5 μm to 100 μm.

11. The apparatus of claim 1, wherein the focal length of the aspherical microlenses in the array of micro-telecentric lenses is in the range of 5-2000 μm.

12. The apparatus of claim 1, wherein one pixel element of the fingerprint sensor corresponds to at least one of the set of micro-telecentric lens arrays.

13. The apparatus of claim 1, wherein the apparatus further comprises:

the filter plate is arranged above the fingerprint sensor and is used for filtering optical signals formed by reflection of human fingers.

14. The device of claim 1, wherein the fingerprint recognition device is fixed below the display screen with a gap therebetween.

15. The apparatus of claim 14, wherein the electronic device further comprises a center, the fingerprint recognition device being secured to the center.

16. The device of claim 14, wherein a foam layer is disposed below the display screen, the foam layer having an aperture at a location where the fingerprint recognition device is mounted, such that the fingerprint recognition device is capable of receiving light signals transmitted from the display screen that are reflected by a human finger.

17. The apparatus of claim 1, wherein the array of micro-telecentric lens arrays are arranged in a square or hexagonal configuration.

18. The apparatus of claim 1, wherein the material of the microlenses in the set of micro-telecentric lens arrays is glass or plastic and/or the microlenses in the set of micro-telecentric lens arrays are realized by a micro-nano machining process or a press molding process.

19. The apparatus of any one of claims 1 to 18, wherein the micro-aperture stops in the array of micro-telecentric lenses are fabricated by a micro-nano machining process or a nano-printing process.

20. An electronic device comprising a display screen and a fingerprint recognition device according to any one of claims 1 to 19, the fingerprint recognition device being arranged below the display screen.

21. The electronic device of claim 20, wherein a gap exists between the fingerprint recognition device and the display screen.

22. The electronic device of claim 21, further comprising a bezel, wherein the fingerprint recognition device is secured to the bezel.

23. The electronic device of any one of claims 20 to 22, wherein a foam layer is provided below the display screen, the foam layer having an aperture in a mounting location of the fingerprint recognition device to enable the fingerprint recognition device to receive light signals transmitted from the display screen formed by reflection by a human finger.