CN210142329U

CN210142329U - Fingerprint identification device and electronic equipment

Info

Publication number: CN210142329U
Application number: CN201921009800.4U
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: 2020-03-13
Anticipated expiration: 2028-12-26
Also published as: CN209168151U

Abstract

The embodiment of the application provides a fingerprint identification device and electronic equipment, and the fingerprint identification device comprises: the micro telecentric lens array group receives an optical signal formed by reflection of a human finger; and the fingerprint sensor is arranged below the micro telecentric lens array group and is used for imaging based on the optical signal passing through the micro telecentric lens array group. The fingerprint identification device and the electronic equipment of the embodiment of the application can avoid light loss in the vertical direction and further reduce the exposure time of the fingerprint sensor compared with the scheme of the periodic through hole array. Compared with the scheme of a micro lens, the fingerprint identification device can reduce the imaging distortion of the whole system. The fingerprint identification device can improve the imaging quality and the contrast.

Description

Fingerprint identification device and electronic equipment

The application is a divisional application of a utility model with the application date of 2018, 12 and 26, and the application number of 201822214046.X and the name of '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 types of techniques for optical fingerprint recognition devices under the screen. The first is an under-screen optical fingerprint identification technology based on a periodic micropore array, and the scheme has large light energy loss and long sensor exposure time; the other is an off-screen optical fingerprint identification technology based on a micro lens, and the imaging distortion of the fingerprint identification device is large.

SUMMERY OF THE UTILITY MODEL

In view of this, embodiments of the present disclosure provide a fingerprint identification apparatus and an electronic device, which can avoid light loss in a vertical direction and further reduce an exposure time of a fingerprint sensor, compared with a scheme of a periodic via array. Compared with the scheme of a micro lens, the fingerprint identification device can reduce the imaging distortion of the whole system. Therefore, the fingerprint identification device of the embodiment of the application enables the imaging quality and the contrast of fingerprint identification to be greatly improved.

In a first aspect, a fingerprint identification device is provided, which includes: the micro telecentric lens array group receives an optical signal formed by reflection of a human finger; and the fingerprint sensor is arranged below the micro telecentric lens array group and is used for imaging based on the optical signal passing through the micro telecentric lens array group.

In one possible implementation, the micro telecentric lens array group includes: a double telecentric lens array receiving the optical signal in a vertical direction; and the object space telecentric lens array is arranged below the double telecentric lens array, collimates and focuses the optical signal transmitted by the double telecentric lens array, and transmits the optical signal to the fingerprint sensor.

In one possible implementation, the double telecentric lens array includes a plurality of double telecentric lens units, the double telecentric lens units include a first microlens, a second microlens, and a first aperture stop disposed between the first microlens and the second microlens; and/or the object space telecentric lens array comprises a plurality of object space telecentric lens units, and each object space telecentric lens unit comprises a third micro lens and a second micro-aperture diaphragm arranged below the third micro lens.

In a possible implementation, 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 microlenses.

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 aperture stop is in the range of 20 μm to 1 μm, and the thickness of the first aperture stop is in the range of 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 micro-aperture stop and/or the second micro-aperture stop may be 500 nm.

In one possible implementation, the first micro-aperture stop includes a double-tapered hole with a taper angle equal to an angle at which the marginal rays of the first microlens converge, and/or the second micro-aperture stop includes a single-tapered hole with a taper angle equal to an angle at which the marginal rays of the third microlens converge.

In one possible implementation, the micro telecentric lens array group comprises spherical micro lenses and/or aspherical micro lenses.

Optionally, the radius of curvature of the spherical microlenses in the micro telecentric lens array group ranges from 5 μm to 100 μm. The focal length range of the aspheric surface type micro lens in the micro telecentric lens array group is 5-2000 mu m.

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 a 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 have one-to-one correspondence with the pixel units of the fingerprint sensor. The double telecentric lens array and the object space telecentric lens array 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 also correspond to a plurality of double telecentric lens units.

In one possible implementation, the apparatus further includes: the filter, set up in fingerprint sensor's top filters the light signal who is formed by human finger reflection.

In a possible implementation manner, when the fingerprint identification device is applied to an electronic device with a display screen, the fingerprint identification device is fixed below the display screen, and a gap exists between the fingerprint identification device and the display screen.

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

In a possible implementation manner, a foam layer is arranged below the display screen, and the foam layer is provided with an opening at the installation position of the fingerprint identification device, so that the fingerprint identification device can receive the optical signal formed by reflection of the human finger and transmitted by the display screen.

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

In one possible implementation manner, the space between the microlenses in the micro-telecentric lens array group and the micro-aperture stop in the micro-telecentric lens array group and/or the space between the microlenses in the micro-telecentric lens array group and the microlenses in the micro-telecentric lens array group 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 aperture stop may be filled with air, the space between the first aperture stop and the second microlens may be filled with glass, or the like.

In a possible implementation manner, the material of the micro-lenses in the micro-telecentric lens array group is glass or plastic, and/or the micro-lenses in the micro-telecentric lens array group are implemented by a micro-nano processing technology or a compression molding technology.

In a possible implementation manner, the aperture diaphragm of the micro-aperture in the micro-telecentric lens array group is manufactured by a micro-nano processing technology or a nano printing technology.

In a second aspect, an electronic device is provided, which includes a display screen and the fingerprint identification device in the first aspect or any possible implementation manner of the first aspect, and the fingerprint identification device is disposed below the display screen.

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

Alternatively, the distance between the fingerprint recognition device and the display screen may be 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 to the pixel unit of the fingerprint sensor. And by miniaturizing and arraying the telecentric lens, fingerprint imaging within a certain distance can be realized. 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 a micro lens, the fingerprint identification device can reduce the imaging distortion of the whole system. The fingerprint identification device can achieve high 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 identification device according to an embodiment of the present application.

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

Fig. 4 shows an imaging principle diagram of the image-side telecentric lens.

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

Fig. 6 is a schematic block diagram of a micro telecentric lens array group in the embodiment of the present application.

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

Fig. 8 is an assembly structure view of the fingerprint recognition device according to 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 make those skilled in the art better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of them. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application shall fall within the scope of the protection of the embodiments in the present application.

According to a common application scenario, 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 an entire area below 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 embodiment of the present application is applicable, the terminal device 100 includes a display screen 120 and a fingerprint identification device 130, where the fingerprint identification device 130 is disposed in a local area below the display screen 120. The fingerprint recognition device 130 may include a sensing array having a plurality of optical sensing units, wherein the sensing 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 or otherwise verify a fingerprint of the terminal device 100, the user only needs to press a finger on the fingerprint detection area 103 located on the display screen 120, so as to implement fingerprint input. 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 a fingerprint key (such as a Home key).

As a preferred embodiment, the display screen 120 may adopt a display screen having a self-Light Emitting display unit, such as an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. In addition, the display screen 120 may 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 an embodiment, the terminal device 100 may include a touch controller, and the touch controller may be embodied as a touch panel, which may be disposed on a surface of the display screen 120, or may be partially or wholly integrated into the display screen 120, so as to form the touch display screen. Taking an OLED display screen as an example, the fingerprint identification device 130 may use the display unit (i.e., 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.

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 such as a liquid crystal display or other passive luminous display. Taking an application to a liquid crystal display having a backlight module and a liquid crystal panel as an example, to support the underscreen fingerprint detection of the liquid crystal display, the fingerprint identification device 130 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 or disposed in an edge area below a protective cover plate of the terminal device 100, and the fingerprint identification device 130 is disposed below the backlight module, and the backlight module allows the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the sensing array of the fingerprint identification device 130 by performing hole opening or other optical designs on film layers such as a diffusion sheet, a brightness enhancement sheet, a reflection sheet, and the like.

Moreover, the sensing array of the fingerprint identification 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. When a finger presses the fingerprint detection area 103, light emitted by the display unit of the fingerprint detection area 103 is reflected on the fingerprint on the surface of the finger and forms reflected light, wherein the reflected light of the ridges and valleys of the fingerprint is different, and the reflected light passes through the display screen 120 and is received by the photodetector array and converted into a corresponding electrical signal, i.e., a fingerprint detection signal; 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 terminal device 100.

In other alternative embodiments, the fingerprint recognition device 130 may be disposed in the entire area below the display screen 120, so as to extend the fingerprint detection area 103 to the entire display area 102 of the display screen 120, thereby realizing 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, and the cover plate 110 may be a glass cover plate or a sapphire cover plate, which is disposed above the display screen 120 and covers the front surface of the terminal device 100. Therefore, in the embodiment of the present application, the pressing of the finger on the display screen 120 actually means pressing the cover plate 110 above the display screen 120 or pressing a surface of a protective layer covering the cover plate 110.

As an alternative implementation, as shown in fig. 1, the fingerprint identification 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 a chip (Die) through a semiconductor process; that is, the light detecting section 134 may be fabricated in 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 guide layer, and other optical elements; the optical 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 focus) reflected light that is reflected from the surface of the finger to the sensor array for optical detection.

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

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

In particular implementations, the optical assembly 132 may be packaged in the same optical fingerprint chip as the light detection portion 134. The optical component 132 may be mounted inside the fingerprint identification device as a separate component from the optical detection portion 134, that is, the optical component 132 may be disposed outside the chip on which the optical detection portion 134 is disposed, for example, the optical component 132 may be attached to the chip, or some components of the optical component 132 may be integrated into the chip. There are various implementations of the light guiding layer of the optical assembly 132.

In an embodiment, the light guiding layer of the optical component 132 is specifically an optical path modulator or an optical path collimator fabricated on a semiconductor silicon wafer or other substrate (such as silicon oxide or nitride), and has a plurality of optical path modulating units or collimating units, specifically, the optical path modulating units or collimating units may be specifically through holes with high aspect ratios, and thus the plurality of collimating units or lens units may constitute a through hole array. In the reflected light reflected from the finger, the light incident on 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, each optical sensing unit can basically receive the reflected light of the fingerprint texture guided by the through hole above the optical sensing unit, and therefore the sensing array can detect the fingerprint image of the finger.

In other alternative embodiments, the light guide layer may also include an optical Lens (Lens) layer having one or more optical Lens units, such as a Lens group of one or more aspheric microlenses. The reflected light reflected by the finger is collimated or converged by the optical lens unit and 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 sensing Array of the light detection portion 134 may specifically include only a single sensing Array, and may also adopt a Dual sensing Array (Dual Array) or a multi sensing Array (Multiple Array) architecture having two or more sensing arrays arranged side by side. When the light detection portion 134 employs a dual-sensor array or a multi-sensor array architecture, the optical assembly 132 may employ a single light guide layer to cover the two or more sensor arrays simultaneously; alternatively, the optical component 132 may also include two or more light guide 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 for guiding or converging the relevant reflected light to the sensing arrays below the two or more sensing arrays.

In other alternative implementations, the display screen 120 may also be a non-self-luminous display screen, such as a liquid crystal display screen that uses a backlight; in this case, the fingerprint recognition device 130 cannot use the display unit of the display screen 120 as an excitation light source, so that it is necessary to integrate the excitation light source inside the fingerprint recognition device 130 or arrange the excitation light source outside the fingerprint recognition device 130 to realize optical fingerprint detection, and the detection principle is consistent with the above description.

It should be understood that, although the fingerprint identification device is exemplified as an optical fingerprint identification device under a screen in the embodiment shown in fig. 1, in other embodiments, the fingerprint identification device of the terminal device 100 may be replaced by an ultrasonic fingerprint identification device or other types of fingerprint identification devices. The application does not make special restrictions on the type and specific structure of the fingerprint identification device, as long as the fingerprint identification device can meet the performance requirements for fingerprint identification inside the display screen of the terminal equipment.

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

In another implementation, the fingerprint recognition device 130 may use a microlens to transmit light to the sensing array, and since a common lens is used, when the object distance changes during the imaging process, the size of the image formed by the common lens changes accordingly, which may result in a lens with the same focal length corresponding to different object distances, and thus different magnifications will be obtained. In addition, the common lens has a certain range of depth of field, and when the object to be measured is not in the range of the depth of field of the lens, the image becomes fuzzy and cannot be focused clearly. Resulting in poor fingerprint recognition accuracy.

In order to solve the above various problems, embodiments of the present application provide a new fingerprint identification device that may be disposed below a display screen. Specifically, as shown in fig. 2, the fingerprint identification device 200 may include a micro telecentric lens array group 210 and a fingerprint sensor 220, and the micro telecentric lens array group 210 may be disposed above the fingerprint sensor 220. The micro-telecentric lens array 210 is used for receiving the optical signal formed by the reflection of the human finger and in the vertical direction, and further collimating and focusing the optical signal. The fingerprint sensor 220 is used for imaging based on the light signal passing through the micro-telecentric lens array group 210.

For ease of understanding, a brief description of telecentric optics will be provided first.

The telecentric lens is essentially a combination of a common lens and an aperture imaging principle. The method can ensure that the magnification of the obtained image is not changed within a certain object distance range, does not change along with the change of the depth of field, has no parallax, and can improve the precision of fingerprint identification by applying the method to the fingerprint identification technology.

Generally, telecentric lenses can be further classified into an object-side telecentric lens, an image-side telecentric lens, and a double telecentric lens. The principles of various telecentric lenses are described below in conjunction 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 disposed at the image focal plane of the ordinary lens, and the aperture stop is used to allow only parallel incident object rays (such as ray 1 and ray 2) to reach the image plane for imaging, and it can be seen from the geometrical relationship that the image has no relationship of magnitude. That is, it corresponds to an object at infinity.

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

Fig. 5 shows the imaging principle of a double telecentric lens. As shown in fig. 5, the double telecentric lens has the advantages of both the object-side telecentric lens and the image-side telecentric lens. The lens is composed of two groups of lenses (such as a lens 1 and a lens 2), and an aperture stop is arranged on a confocal plane of the two groups of lenses to enable principal rays (such as the ray 1 and the ray 2) to be parallel to an optical axis in an object space and an image space.

Since a single telecentric lens is used for imaging, a relatively large imaging surface is usually required, and the entire lens group is relatively thick. However, after the telecentric lens is arrayed and miniaturized, an object at a certain distance can be imaged, so that the telecentric lens can be applied to the fingerprint identification technology. And the telecentric lens after the array miniaturization constitutes the micro telecentric lens array group 210 in the fingerprint identification device 200 provided by the embodiment of the application.

The micro-telecentric lens array group can be a combination of various arrayed and miniaturized telecentric lens units as the name implies. For example, as shown in fig. 6, the micro telecentric lens array group 210 may include a double telecentric lens array 211 and an object-side telecentric lens array 212, and the object-side 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 light signals transmitted from the double telecentric lens array 211, and the sensing array of the fingerprint sensor 220 can receive the light signals transmitted from the object-side telecentric lens array 212 and perform imaging based on the light signals.

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

Alternatively, the micro telecentric lens array group 210 may also be provided with only one micro aperture diaphragm array below the double telecentric lens array. That is, after the light signal formed by the reflection of the finger passes through the display screen, it may pass through the microlens array 1, the aperture stop array 1, the microlens array 2 or the microlens array 3, and the aperture stop array 2 in this order as shown in fig. 7, 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, 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 the light transmitted by the double telecentric lens array and transmitting the light to the fingerprint sensor.

It should be understood that, in the fingerprint identification device provided in the embodiment of the present application, the micro telecentric lens array group and the fingerprint sensor are mainly composed of a micro lens array and a micro aperture diaphragm array. How to combine the three telecentric lens implementations in fig. 3 to 5 is not specifically limited herein.

Optionally, in the embodiment of the present application, the space between the microlens and the aperture stop and/or the space between the microlens and the microlens are filled with air, glass, plastic, or any other transparent material, or any combination of the above transparent materials may also be used. For example, the filling between the microlens array 1 and the microaperture diaphragm array 1, between the microaperture diaphragm 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 microaperture diaphragm array 2 in fig. 7 may be the same or different. For example, it may be all air, glass, plastic, or the like. Or the filling between the micro lens and the micro aperture diaphragm and between the micro lens and the micro lens can be different. For example, the space between the micro lens and the micro aperture stop may be filled with air, and the space between the micro lens and the micro lens may be filled with glass, which is not limited in this application.

Optionally, the micro-lens in the embodiment of the present application may be implemented by a micro-nano processing process or a die-pressing process, and the micro-aperture diaphragm in the embodiment of the present application may be manufactured by a micro-nano processing process or a nano printing process, so that the micro-array of the telecentric lens may be implemented.

Those skilled in the art understand that a double telecentric lens unit consists of two microlenses and a microaperture stop, and an object-side telecentric lens unit consists of one microlens and a microaperture stop. And the micro-aperture stop in the double telecentric lens unit may be disposed at the confocal plane of the two microlenses. That is, the focal points of the two microlenses coincide, and an aperture stop is inserted at the position where the focal points coincide, so that a double telecentric lens unit is formed. And arranging a micro-aperture diaphragm in the object space telecentric lens unit at an image space focal plane of the micro lens. 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, symmetrical with respect to the micro-aperture diaphragm. If the focal lengths of the two microlenses are different, the two microlenses may be asymmetric with respect to the confocal plane. In other words, the two microlenses are no longer symmetrical about the 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-side telecentric lens unit may have a certain thickness, and then the micro-aperture stops may be cylindrical holes or may not be cylindrical holes. For example, the aperture stops in the double telecentric lens units may be double-tapered holes at opposite tops, and the aperture stops in the object-side telecentric lens array may be single-tapered holes. And the cone angle angles of the pair of top double tapered holes and the single tapered hole may be the same as the angle at which the edge rays of light passing through the microlens thereabove converge. It should be understood that the dual taper hole or the single taper hole can be conical or triangular, and is not limited herein.

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

Optionally, in this embodiment of the application, one micro telecentric lens group in the micro telecentric lens array group may correspond to one pixel unit of the fingerprint sensor. The micro telecentric lens group can comprise a double telecentric lens unit and an object space telecentric lens unit. Specifically, the object-side telecentric lens units in the object-side telecentric lens array may correspond one-to-one to the pixel units of the fingerprint sensor. The double telecentric lens array and the object space telecentric lens array 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 also correspond to a plurality of double telecentric lens units.

Alternatively, one micro telecentric lens group in the micro telecentric lens array group may correspond 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 assigned to 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 have a smaller period than that of the telecentric lens unit.

For an arrayed telecentric lens, the individual pixel periods need to be related to the resolution requirements of the object, for example a fingerprint recognition device placed under the display screen, the pixel periods of the telecentric lens can be set to a sampling rate of 25 μm each along the planar X/Y direction of the display screen.

The fingerprint identification device that this application embodiment provided adopts telecentric lens, can carry out fingerprint collection to telecentric lens top region to focus the pixel cell to fingerprint sensor with the light in the perpendicular region in top. And by miniaturizing and arraying the telecentric lens, fingerprint imaging within a certain distance can be realized. 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 a micro lens, the fingerprint identification device can also reduce the imaging distortion of the whole system, and can achieve higher imaging quality and contrast.

Alternatively, in the embodiment of the present application, for the double telecentric lens, the diameter of the aperture stop may be in the range of 20 μm to 1 μm, and the thickness of the aperture stop may be in the range of 100nm to 100 μm, for example, the thickness may be 500 nm. For an object-side telecentric lens, the diameter of the aperture stop is in the range of 500nm to 20 μm, and the thickness of the aperture stop may be in the range of 100nm to 100 μm. Alternatively, the surface shape of each microlens in the telecentric lens can be spherical or aspherical, that is, the surface shape of the microlens in the telecentric lens group composed of one double telecentric lens unit and one object-side telecentric lens unit can be either spherical or aspherical, or either one of them can be spherical or aspherical. Alternatively, the radius of curvature of the spherical microlens 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 of the aspherical type microlens may be a value between 5 μm and 2000 μm, and specifically, may be a value between 5 μm and 500 μm.

Alternatively, the distance between the double telecentric lens array and the object-side telecentric lens array may be less than or equal to 200 μm. For example, it may be in the range of 1 μm to 200. mu.m. In particular, the distance between the double telecentric lens array and the object-side telecentric lens array may be set to be less than 50 μm.

Optionally, in this embodiment of the application, the material of the micro telecentric lens array group may be glass, plastic, or other transparent materials. In addition, the arrangement mode 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 this application.

Optionally, as shown in fig. 7, the fingerprint identification device 200 of the embodiment of the present application may further include a filter for filtering the light signal reflected by the finger. The filter may be between the fingerprint sensor and the display screen below, for example, may be disposed 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 be below the micro telecentric lens array group, and may also be disposed between the micro telecentric lens array group and the display screen, that is, above the micro telecentric lens array group; or, two layers of filter plates can be included, and the two layers of filter plates are respectively arranged above and below the micro-telecentric lens array group. In other alternative embodiments, the filter may be disposed inside the micro telecentric lens array group, for example, between the double telecentric lens array and the object-side telecentric lens array, or may even be omitted, which is not limited in this application.

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

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

Fig. 8 shows a schematic structural diagram of a fingerprint identification device provided in an embodiment of the present application. When the fingerprint identification device is applied to an electronic device (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 identification device 330 may be fixedly disposed below the display screen 320, and the lower surface of the fingerprint identification 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 identification device 330 may be installed below the display screen 320 by being fixedly connected to an easily detachable device inside the terminal device, for example, the fingerprint identification device 330 may be installed on a lower surface of a middle frame 370, the middle frame 370 may serve as a fixing frame between the fingerprint identification 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 by using a foam back adhesive 360. The middle frame 370 is disposed between the display screen 320 and the rear cover and is used for supporting a frame of various internal components, including but not limited to a battery, a main board, a camera, a cable, various sensors, a microphone, an earphone, and other components. 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 mounted between the display 320 and the middle frame 370 with a gap from the display 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 arrangement position of the fingerprint identification device is not limited any more.

Alternatively, the distance between the fingerprint recognition device 330 and the display screen 320 may be greater than or equal to 600 μm. The safe distance between the fingerprint identification 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 a whole. For example, the frame may be a metal border only, or a metal-like coating may be applied to the middle frame. Further, the middle frame 370 may also be a composite middle frame, taking a mobile phone as an example, the middle frame 370 includes an inner middle frame 1 and an outer middle frame 2, the inner middle frame 1 is used for bearing parts of the mobile phone, the outer middle frame 2 is outside the inner middle frame 1, the outer edge of the outer middle frame 2 is provided with a mobile phone key, and the inner middle frame 1 and the outer middle frame 2 are integrated into a whole. Because the mobile phone middle frame is designed into the inner middle frame and the outer middle frame, and the inner middle frame and the outer middle frame are integrated into a whole, when the mobile phone is impacted, firstly the outer middle frame is worn, and because only the keys are arranged on the outer middle frame, the outer middle frame is simple and convenient to replace, and the cost is low; furthermore, an elastic material can be arranged between the inner and outer middle frames, and the inner and outer middle frames are relatively fixed under the compression of the elastic force of the elastic layer, so that the impact of the elastic layer on the inner and outer middle frames can be reduced when the outer middle frame bears the impact force.

Optionally, a layer of foam may be disposed below the display screen 320, and a closed environment may be formed between the lower portion of the display screen 320 and the fingerprint identification device 330, so as to meet the requirements of light shielding and dust prevention. The foam layer may be perforated at the installation position 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 light passes through the display screen. A fingerprint is a diffuse reflector whose reflected light is present in all directions. The fingerprint sensor only receives light in the vertical direction by using a specific light path, and the fingerprint can be calculated by 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 according to an embodiment of the application. The electronic device 400 shown in fig. 9 includes: radio Frequency (RF) circuitry 410, memory 420, other input devices 430, display 440, sensors 450, audio circuitry 460, I/O subsystem 470, processor 480, and power supply 490. Those skilled in the art will appreciate that the electronic device configuration shown in fig. 7 does not constitute a limitation of the electronic device and may include more or fewer components than shown, or some components may be combined, or some components may be split, 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 than or the illustrated User interfaces.

The following describes each component 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 information transmission and reception or during a call, and in particular, receives downlink information of a base station and then processes the received downlink information to the processor 480; in addition, the data for designing uplink is transmitted to the base station. Typically, the RF circuitry includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a Low Noise Amplifier (LNA), a duplexer, 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, and the processor 480 executes various functional applications and data processing of the electronic device 400 by operating 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 required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data (such as audio data, a phonebook, etc.) created according to the use of the electronic device 400, and the like. Further, the 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 generate signal inputs relating 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 is an extension of a touch-sensitive surface formed by a screen), and the like. The other input devices 430 are connected to other input device controllers 471 of the I/O subsystem 470 and interact with the processor 480 through signals under the control of the other input device controllers 471.

The display screen 440 may be used to display information input by or provided to the user as well as various menus of the electronic device 400 and may also accept user input. The display 440 may be a touch screen, and may include a display panel 441 and a touch panel 442. Touch panel 442 may overlay display panel 441, a user may operate on or near touch panel 442 overlaid on display panel 441 according to content displayed on display panel 441 (including, but not limited to, a soft keyboard, a virtual mouse, virtual keys, icons, etc.), touch panel 442, upon detecting an operation thereon or near, may be communicated to processor 480 via I/O subsystem 470 to determine user input, and processor 480 may then provide corresponding visual output on display panel 441 according to the user input via I/O subsystem 470. Although in fig. 8, the touch panel 442 and the display panel 441 are two separate components to implement the input and output 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 include at least one sensor 450, for example, the sensor 450 may be a fingerprint sensor located under the display screen 440 or in the display screen 440, i.e., a fingerprint recognition device in the embodiment of the present application.

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

The I/O subsystem 470 controls input and output of external devices, which may include other device input controllers 471, sensor controllers 472, and display controllers 473. Optionally, one or more other input control device controllers 471 receive signals from and/or transmit signals to other input devices 430, and the other input devices 430 may include physical buttons (push buttons, rocker buttons, etc.), dials, slide switches, joysticks, click wheels, a light mouse (a light mouse is a touch-sensitive surface that does not display visual output, or is an extension of a touch-sensitive surface formed by a screen). It is noted that other input control device controllers 471 can be coupled to any one or more of the devices described above. The display controller 473 in the I/O subsystem 470 receives signals from the display screen 440 and/or sends signals to the display screen 440. After the display screen 440 detects the 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., implements a human-machine interaction. The sensor controller 472 may receive signals from one or more sensors 440 and/or send signals to one or more sensors 440.

The processor 480 is a control center of the electronic device 400, connects various parts of the entire electronic device using various interfaces and lines, performs various functions of the electronic device 400 and processes data by operating or executing software programs and/or modules stored in the memory 420 and calling data stored in the memory 420, thereby monitoring the electronic device as a whole. Optionally, processor 480 may include one or more processing units; preferably, the processor 480 may integrate an application processor, which mainly handles operating systems, user interfaces, application programs, etc., and a modem processor, which mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into processor 480. The processor 480 may be configured to perform various steps in the method embodiments of the present application.

Electronic device 400 also includes a power supply 490 (e.g., a battery) for powering the various components, which may preferably be logically coupled to processor 480 via a power management system that may enable managing charging, discharging, and power consumption via the power management system.

Although not shown, the electronic device 400 may further include a camera, a bluetooth module, and the like, which are not described in detail 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 various illustrative elements and circuits described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the several embodiments provided in the present application, it should be understood that the disclosed circuits, branches and units may be implemented in other manners. For example, the above-described branch is illustrative, and for example, the division of the unit is only one logical function division, and there may be other division ways in actual implementation, for example, multiple units or components may be combined or integrated into one branch, or some features may be omitted, or not executed.

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 or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including 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: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

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

Claims

1. A fingerprint recognition device, comprising:

a micro telecentric lens array group for receiving optical signals formed by reflection of human fingers, the micro telecentric lens array group comprising:

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

and the object space telecentric lens array is arranged below the double telecentric lens array and is used for collimating and focusing the optical signals transmitted by the double telecentric lens array.

2. The apparatus of claim 1, wherein the array of double telecentric lenses comprises a plurality of double telecentric lens units comprising a first microlens, a second microlens.

3. The apparatus of claim 2, wherein the double telecentric lens unit further comprises a first micro-aperture stop disposed between the first microlens and the second microlens and at a confocal plane of the first microlens and the second microlens.

4. The apparatus of claim 3, wherein the object-side telecentric lens array comprises a plurality of object-side telecentric lens units, and wherein the object-side telecentric lens units comprise third microlenses and second micro-aperture stops disposed below the third microlenses.

5. The apparatus of claim 4, wherein the second micro-aperture stop is disposed at an image-side focal plane of the third microlens.

6. The apparatus of claim 3, wherein the first micro-aperture stop comprises a double-tapered hole with a cone angle equal to an angle at which the edge rays of the first micro-lens converge.

7. The apparatus of claim 4, wherein the second micro-aperture stop comprises a single tapered aperture having a cone angle that is the same as an angle at which marginal rays passing through the third microlens converge.

8. The device according to claim 4, wherein the space between the micro-lenses in the micro-telecentric lens array group and the micro-aperture stop in the micro-telecentric lens array group, and/or the space between the micro-lenses in the micro-telecentric lens array group and the micro-lenses in the micro-telecentric lens array group is filled by any combination of the following transparent media: air, glass and plastic.

9. The apparatus of claim 1, further comprising a fingerprint sensor disposed below the array of micro-telecentric lenses and configured to image based on the light signals passing through the array of micro-telecentric lenses;

and one pixel unit of the fingerprint sensor corresponds to at least one micro telecentric lens group in the micro telecentric lens array group.

10. The apparatus of claim 1, further comprising:

the fingerprint sensor is arranged below the micro telecentric lens array group and performs imaging based on the optical signal passing through the micro telecentric lens array group;

the filter plate, set up in the top of little telecentric mirror head array group, and/or fingerprint sensor with between the little telecentric mirror head array group, filter the light signal that forms by human finger reflection.

11. The device of claim 1, wherein when the fingerprint recognition device is applied to an electronic device having a display screen, the fingerprint recognition device is fixed below the display screen and has a gap with the display screen.

12. The apparatus of claim 11, wherein the electronic device further comprises a middle frame, and the fingerprint recognition device is fixed on the middle frame.

13. The device of claim 11, wherein a foam layer is disposed below the display screen, the foam layer having an opening at a location where the fingerprint recognition device is mounted to enable the fingerprint recognition device to receive a light signal transmitted through the display screen via reflection from a human finger.

14. The apparatus of claim 1, wherein the array of micro-telecentric lenses is arranged in a square or hexagonal pattern.

15. The device of claim 4, wherein the material of the microlenses in the array group of telecentric lenses is glass or plastic.

16. The apparatus of claim 4, wherein the first micro-aperture stop has a diameter ranging from 20 μm to 1 μm and a thickness ranging 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.

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

18. The apparatus of claim 1, wherein the micro telecentric lens array group comprises spherical microlenses and/or aspherical microlenses.

19. An electronic device, comprising a display and a fingerprint recognition device according to any one of claims 1 to 18, the fingerprint recognition device being disposed below the display.