Fingerprint imaging module and electronic device

Abstract

The present invention provides a fingerprint imaging module and an electronic device. The fingerprint imaging module includes: an OLED screen, which is used to emit a first light; the first light is reflected after reaching the finger to form a reflected light that penetrates the OLED screen; an optical waveguide, which is arranged on one side of the OLED screen and is used to transmit the reflected light by continuous reflection; an imaging element, which is arranged on a side of the optical waveguide away from the OLED screen and is used to process the reflected light to obtain a fingerprint image. The fingerprint imaging module allows the imaging element to be arranged at any position on one side of the optical waveguide, which is conducive to the flexible layout of the circuit under the screen.

Description

Technical Field

[0001] The invention belongs to the field of pattern recognition, and relates to a fingerprint recognition device, in particular to a fingerprint imaging module and an electronic device. Background Art

[0002] With the development of technology and the increase in user demand, screen fingerprint technology has been widely used in electronic devices such as mobile phones. Screen fingerprint technology is a hidden fingerprint design under the screen. Users only need to place their fingers on a specific fingerprint imaging area on the screen to achieve fingerprint imaging and recognition. The principle of screen fingerprint technology is: when the finger is placed in the fingerprint imaging area, the light emitted by the light source penetrates the cover plate to illuminate the fingerprint texture, and the light reflected from the fingerprint penetrates the screen and reaches the imaging element, and finally forms a fingerprint image on the imaging element. Therefore, in the existing screen fingerprint technology, the imaging element needs to be set around the fingerprint imaging area in order to receive the reflected light. This restriction on the setting position of the imaging element is not conducive to the flexible layout of the circuit under the screen. Summary of the invention

[0003] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a fingerprint imaging module and an electronic device for solving the problem that the existing screen fingerprint technology is not conducive to the flexible layout of the under-screen circuit.

[0004] To achieve the above-mentioned purpose and other related purposes, the first aspect of the present invention provides a fingerprint imaging module; the fingerprint imaging module comprises: an OLED screen, used to emit a first light; the first light is reflected after reaching the finger to form a reflected light penetrating the OLED screen; an optical waveguide, arranged on one side of the OLED screen, used to transmit the reflected light by continuous reflection; an imaging element, arranged on a side of the optical waveguide away from the OLED screen, used to process the reflected light to obtain a fingerprint image.

[0005] In an embodiment of the first aspect, the fingerprint imaging module further includes: a first optical element, disposed on a side of the OLED screen close to the optical waveguide, for changing a transmission direction of the reflected light so that the reflected light is transmitted in the optical waveguide in a continuous reflection manner; a second optical element, disposed on a side of the OLED screen close to the optical waveguide, for further changing a transmission direction of the reflected light transmitted in the optical waveguide so that the reflected light leaves the optical waveguide and reaches the imaging element.

[0006] In an embodiment of the first aspect, the first optical element is a reflective surface and is disposed on the optical waveguide by coating; and / or the second optical element is another reflective surface and is disposed on the optical waveguide by coating.

[0007] In an embodiment of the first aspect, the fingerprint imaging module further includes: at least one semi-transmissive and semi-reflective element, disposed between the first optical element and the second optical element, for allowing the reflected light transmitted in the optical waveguide and transmitted through the first optical element to pass through at least one of the semi-transmissive and semi-reflective elements and be transmitted to the second optical element.

[0008] In one embodiment of the first aspect, the first optical element is a reflective element, a refracting element, a diffractive element or a semi-transparent and semi-reflective element; and / or the second optical element is a reflective element, a refracting element, a diffractive element or a semi-transparent and semi-reflective element.

[0009] In an embodiment of the first aspect, the first light is quasi-parallel light.

[0010] In an embodiment of the first aspect, the reflected light is transmitted in the optical waveguide in a total reflection manner.

[0011] In an embodiment of the first aspect, the imaging element is a charge coupled device sensor or a complementary metal oxide semiconductor sensor or a quantum thin film photoelectric sensor.

[0012] In an embodiment of the first aspect, the fingerprint imaging module further includes: a substrate, which is disposed on a side of the optical waveguide away from the OLED screen and is used to carry the optical waveguide and the imaging element.

[0013] A second aspect of the present invention further provides an electronic device, comprising any one of the above-mentioned fingerprint imaging modules.

[0014] As described above, the fingerprint imaging module and electronic device of the present invention have the following beneficial effects:

[0015] The fingerprint imaging module includes an optical waveguide, which is used to transmit the reflected light to the imaging element, so that the imaging element can be arranged away from the fingerprint imaging area, which is conducive to the flexible layout of the under-screen circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Shown is a schematic structural diagram of the fingerprint imaging module of the present invention in a specific embodiment.

[0017] Figure 2A Shown is a schematic structural diagram of the fingerprint imaging module of the present invention in a specific embodiment.

[0018] Figure 2B Shown is a schematic structural diagram of the fingerprint imaging module of the present invention in another specific embodiment.

[0019] Figure 2CShown is a schematic structural diagram of the fingerprint imaging module of the present invention in yet another specific embodiment.

[0020] Figure 3 Shown is a schematic structural diagram of the fingerprint imaging module of the present invention in a specific embodiment.

[0021] Figure 4A Shown is a light path diagram of the fingerprint imaging module of the present invention in a specific embodiment.

[0022] Figure 4B Shown is a light path diagram of the fingerprint imaging module of the present invention in a specific embodiment.

[0023] Figure 5 Shown is a schematic structural diagram of the fingerprint imaging module of the present invention in a specific embodiment.

[0024] Fig. 6A Shown is a schematic structural diagram of the electronic device of the present invention in a specific embodiment.

[0025] Figure 6B Shown is a schematic structural diagram of the electronic device of the present invention in another specific embodiment.

[0026] Figure 6C Shown is a schematic structural diagram of the electronic device of the present invention in yet another specific embodiment.

[0027] Component number description

[0028] 1 Fingerprint imaging module

[0029] 11 OLED screen

[0030] 12 Optical waveguide

[0031] 13 Imaging element

[0032] 14. First reflective element

[0033] 15. Second reflective element

[0034] 16 Fingerprint imaging area

[0035] 17. First refractive element

[0036] 18. Second refractive element

[0037] 21 First Light

[0038] 22 Reflected Light

[0039] 3 Fingerprint imaging module

[0040] 31 OLED screen

[0041] 32 Optical waveguide

[0042] 33 Collimation layer

[0043] 34 Imaging element

[0044] 35 Transflective Array

[0045] 351 First transflective element

[0046] 352 Second transflective element

[0047] 353 The third transflective element

[0048] 36 second reflective element

[0049] 37 Fingerprint imaging area

[0050] 41 First Light

[0051] 42 Reflected Light

[0052] 43 Collimated light

[0053] 44 First reflected light

[0054] 45 First transmitted light

[0055] 46 Refracted Light

[0056] 47 Second reflected light

[0057] 44' Second transmitted light

[0058] 45' Third reflected light

[0059] 46' Second Refraction

[0060] 47' The Fourth Reflection

[0061] 6 Electronic devices

[0062] 61 Fingerprint imaging area

[0063] 62 Imaging Elements DETAILED DESCRIPTION

[0064] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0065] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention. The illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0066] The principle of screen fingerprint technology is: when the finger is placed on the fingerprint imaging area, the light emitted by the light source penetrates the cover plate to illuminate the fingerprint texture, and the light reflected from the fingerprint penetrates the screen to reach the imaging element, and finally forms a fingerprint image. Therefore, in some embodiments of the fingerprint imaging module, the imaging element needs to be arranged around the fingerprint imaging area in order to receive the reflected light. This restriction on the setting position of the imaging element is not conducive to the flexible layout of the circuit under the screen. In response to this technical problem, the present invention provides a fingerprint imaging module; the fingerprint imaging module includes an optical waveguide, and no matter where the imaging element is arranged, the optical waveguide can transmit the reflected light to the imaging element and realize the user's fingerprint imaging. Therefore, the fingerprint imaging module of the present invention does not restrict the position of the imaging element, which is conducive to the flexible layout and ultra-thin design of the circuit under the device screen.

[0067] See also Figure 1 In one embodiment of the present invention, the fingerprint imaging module 1 comprises:

[0068] The OLED screen 11 is used to emit a first light ray 21; wherein the first light ray 21 is a beam of light, which includes a plurality of light rays. Preferably, the first light ray 21 is invisible light. When the user places a finger fingerprint on the fingerprint imaging area 16 on one side of the OLED screen 11, the first light ray 21 is reflected after reaching the user's finger fingerprint and forms a reflected light ray 22 that penetrates the OLED screen. Since the surface of the finger fingerprint is uneven, the reflected light rays formed by different light rays in the first light ray 21 irradiating different positions on the finger surface have different angles and intensities. The imaging element can obtain the user's fingerprint information by analyzing the reflected light ray 22, so it can be considered that the reflected light ray 22 carries the user's fingerprint information.

[0069] The optical waveguide 12 is disposed on the side of the OLED screen 11 away from the fingerprint, and is a medium that guides the reflected light 22 to propagate therein. The optical waveguide 12 can transmit the reflected light 22 to the imaging element 13 by continuous reflection. The user can make the reflected light 22 enter or leave the optical waveguide 12 by adjusting the shape, position, number of the optical waveguide 12 and / or using existing optical elements, and the specific method is not limited in this embodiment.

[0070] The imaging element 13 is disposed on a side of the optical waveguide 12 away from the OLED screen, and is used to process the reflected light 22 to obtain a fingerprint image. Specifically, the reflected light 22 carries the fingerprint information of the user, and the imaging element 13 can obtain the fingerprint image of the user by performing photoelectric conversion on the reflected light 22 and extracting the fingerprint information therein.

[0071] In this embodiment, the fingerprint imaging module includes an optical waveguide 12; the optical waveguide 12 can transmit the reflected light 22 carrying fingerprint information to the imaging element 13 by continuous reflection, thereby obtaining the user's fingerprint image. The existence of the optical waveguide 12 allows the imaging element 13 to be arranged away from the fingerprint imaging area 16. Therefore, during the layout of the under-screen circuit, the imaging element 13 can be arranged at any position according to actual needs, which is conducive to the flexible layout and ultra-thin design of the under-screen circuit.

[0072] In addition, the fingerprint imaging module described in this embodiment also makes the position of the fingerprint imaging area not limited by the position of the imaging element. Therefore, in actual applications, the fingerprint imaging area can be set at different positions of the screen according to different needs, thereby realizing flexible fingerprint imaging.

[0073] In one embodiment of the present invention, the multiple light rays emitted by the OLED screen 11 are used for screen display of the device; the first light 21 is a part of the multiple light rays. Therefore, the fingerprint imaging module of this embodiment can be realized by using the OLED screen in the existing device. In practical applications, it is only necessary to add an optical waveguide and an imaging element on one side of the OLED screen to realize the fingerprint imaging module, which is low in cost and simple to assemble.

[0074] In addition, in some embodiments, a separate light source is selected to perform fingerprint imaging, while the fingerprint imaging module described in this embodiment can use the light emitted by the OLED screen itself as the first light 21. In contrast, the fingerprint imaging module described in this embodiment does not need to be provided with a separate light source, which is beneficial to reducing hardware costs and facilitating the realization of an ultra-thin design of the product.

[0075] In practical applications, in order to meet different circuit layout requirements, the imaging element 13 can be attached to one side of the optical waveguide 12, such as Figure 2A The imaging element 13 and the optical waveguide 12 may also be separated from each other, as shown in Figure 2B shown.

[0076] In one embodiment of the present invention, in order to reduce the energy loss of the reflected light when it is transmitted in the optical waveguide, the reflected light is transmitted in the optical waveguide in a total reflection manner. Total reflection is also called total internal reflection. In this embodiment, the refractive index of the optical waveguide 12 is greater than the refractive index of its adjacent medium. At this time, when the reflected light 22 is transmitted to the interface between the optical waveguide 12 and its adjacent medium, if the incident angle of the reflected light 22 is greater than a certain critical angle, its refracted light will disappear, and all the reflected light 22 will be completely reflected without entering the adjacent medium of the optical waveguide 12.

[0077] In one embodiment of the present invention, the fingerprint imaging module further includes: a first optical element and a second optical element. The first optical element is disposed on a side of the OLED screen close to the optical waveguide, and is used to change the transmission direction of the reflected light so that the reflected light is transmitted in the optical waveguide in a continuous reflection manner; the second optical element is disposed on a side of the OLED screen close to the optical waveguide, and is used to further change the transmission direction of the reflected light transmitted in the optical waveguide so that the reflected light leaves the optical waveguide and reaches the imaging element.

[0078] See also Figure 2A and Figure 2B In one embodiment of the present invention, the first optical element is a first reflective element 14. The first reflective element 14 is disposed on a side of the OLED screen 11 close to the optical waveguide 12, and is used to change the transmission direction of the transmission light 22 in the form of reflection, so that the reflected light 22 is transmitted in the optical waveguide 12 in a continuous reflection manner. The first reflective element 14 can be implemented by a reflective element such as a plane mirror, a total reflection prism, etc. Preferably, the first reflective element 14 changes the transmission direction of the transmission light 22 in the form of reflection, so that the reflected light 22 is transmitted in the optical waveguide 12 in a total reflection manner.

[0079] In addition, the first reflective element 14 can be disposed outside the optical waveguide 12. In this case, the reflected light 22 penetrates the OLED screen 11 and reaches the first reflective element 14. The first reflective element 14 changes the transmission direction of the reflected light 22 by reflection, so that the reflected light 22 enters the optical waveguide 12 at a specific angle and is transmitted by continuous reflection. The first reflective element 14 can also be embedded in the optical waveguide 12. In this case, the reflected light 22 penetrates the OLED screen 11 and enters the optical waveguide 12, and then reaches the first reflective element 14. The first reflective element 14 changes the transmission direction of the reflected light 22 by reflection, so that the reflected light 22 is continuously transmitted in the optical waveguide 12 at a specific angle.

[0080] In one embodiment of the present invention, the second optical element is a second reflective element 15. The second reflective element 15 is disposed on a side of the OLED screen 11 close to the optical waveguide 12 and is located near the imaging element 13. The second reflective element 15 is used to further change the transmission direction of the reflected light 22 transmitted in the optical waveguide 12 in a reflection manner, so that the reflected light leaves the optical waveguide 12 and reaches the imaging element 13. The second reflective element 15 can be implemented by a reflective element such as a plane mirror, a total reflection prism, etc.

[0081] The second reflecting surface 15 can be embedded in the optical waveguide 12. At this time, the reflected light 22 is transmitted inside the optical waveguide 12 and reaches the second reflecting surface 15. The second reflecting surface 15 reflects the reflected light 22 to change its optical path and leave the optical waveguide 12 to reach the imaging element 13.

[0082] See also Figure 2C In one embodiment of the present invention, the first optical element is a first refractive element 17. The first refractive element 17 is disposed on a side of the OLED screen 11 close to the optical waveguide 12, and is used to change the transmission direction of the transmission light 22 in the form of refraction, so that the reflected light 22 is transmitted in the optical waveguide 12 in a continuous reflection manner. The first refractive element 17 can be implemented by a prism. The first refractive element 17 can be disposed outside the optical waveguide 12, or can be embedded inside the optical waveguide 12. The specific method is similar to the first reflective element 14, and will not be repeated here.

[0083] In one embodiment of the present invention, the second optical element is a second refractive element 18. The second refractive element 18 is disposed on a side of the OLED screen 11 close to the optical waveguide 12 and is located near the imaging element 13. The second refractive element 18 further changes the transmission direction of the reflected light transmitted in the optical waveguide by refraction, so that the reflected light leaves the optical waveguide and reaches the imaging element. The second refractive element 18 can be implemented by a prism. In addition, the second refractive element 18 can be embedded in the optical waveguide 12, and the specific method is similar to the second reflective element 15, which will not be repeated here.

[0084] In addition, in addition to the above-mentioned reflective elements and refractive elements, the first optical element and the second optical element can also be implemented by diffraction elements; it should be noted that the first optical element and the second optical element of the present invention are not limited to reflective elements, refractive elements and diffraction elements, and any optical element that can change the transmission direction of the reflected light and make the reflected light be transmitted in the optical waveguide in a continuous reflection manner can be used as the first optical element; any optical element that can further change the transmission direction of the reflected light transmitted in the optical waveguide and make the reflected light leave the optical waveguide and reach the imaging element can be used as the second optical element.

[0085] In one embodiment of the present invention, the first reflective element 14 is a reflective surface and is disposed on the optical waveguide by coating; and / or the second reflective element 15 is another reflective surface and is disposed on the optical waveguide by coating. Coating refers to the process of coating one or more layers of metal / dielectric thin film on the surface of an optical part. The coating described in this embodiment can be achieved by vacuum coating or chemical coating. In this embodiment, the first reflective element 14 and / or the second reflective element 15 are disposed on the optical waveguide 12 by coating, which can effectively reduce the thickness of the fingerprint imaging module and reduce the influence of stray light on fingerprint imaging, which is beneficial to improving the imaging quality.

[0086] In one embodiment of the present invention, the fingerprint imaging module further includes at least one semi-transmissive and semi-reflective element, which is disposed between the first optical element and the second optical element, and is used to allow the reflected light transmitted in the optical waveguide and transmitted through the first optical element to pass through at least one of the semi-transmissive and semi-reflective elements and be transmitted to the second optical element. The semi-transmissive and semi-reflective element refers to an element that partially transmits and partially reflects light. In this embodiment, the reflected light transmitted in the optical waveguide in a continuous reflection manner is partially reflected and partially transmitted when it reaches the semi-transmissive and semi-reflective element, wherein: the partially transmitted light continues to be transmitted to the imaging element through the optical waveguide in a continuous reflection manner; the partially reflected light reaches the surface of the optical waveguide after being reflected on the surface of the semi-transmissive and semi-reflective element, and then the energy is gradually consumed after continuous reflection and refraction.

[0087] In one embodiment of the present invention, when the user's finger is within the reflection range of the semi-transparent and semi-reflective element, that is, when the first light emitted by the OLED screen is reflected from the user's finger to form a reflected light penetrating the OLED screen and just hits the semi-transparent and semi-reflective element, the semi-transparent and semi-reflective element acts as the first optical element. At this time, the reflection function of the semi-transparent and semi-reflective element can change the transmission direction of the reflected light 22 in the form of reflection, so that the reflected light 22 is further transmitted in the optical waveguide 12 in a continuous reflection manner. Similarly, if the reflected light hits another semi-transparent and semi-reflective element during transmission in the optical waveguide 12, the semi-transparent and semi-reflective element can allow the light to pass through and further transmit toward the imaging element.

[0088] See also Figure 3 , Figure 4A and Figure 4B In one embodiment of the present invention, the fingerprint imaging module 3 further includes:

[0089] The collimating layer 33 is disposed between the optical waveguide 32 and the OLED screen 31, and is used to collimate the reflected light 42 and obtain the collimated light 43, wherein the collimated light 43 is quasi-parallel light. The quasi-parallel light means that the angle between any two light rays in the light beam is less than a threshold value, and the threshold value is any angle value between 0 and 30 degrees. Preferably, the collimated light 43 is a small-angle light.

[0090] A semi-transparent and semi-reflective element array 35; wherein the semi-transparent and semi-reflective element array is composed of at least one semi-transparent and semi-reflective element according to a specific rule, for example: the semi-transparent and semi-reflective element array 35 is composed of a first semi-transparent and semi-reflective element 351, a second semi-transparent and semi-reflective element 352 and a third semi-transparent and semi-reflective element 353.

[0091] In this embodiment, the user can place the finger within the reflection range of any semi-transmissive and semi-reflective element in the fingerprint imaging area 37. For example, the user can place the finger above the first semi-transmissive and semi-reflective element 351. At this time, the first light 41 emitted by the OLED screen 31 irradiates the surface of the user's finger and forms a reflected light 42; the reflected light 42 is collimated by the collimating layer 33 to form a collimated light 43; the collimated light 43 reaches the corresponding semi-transmissive and semi-reflective element, for example, the first semi-transmissive and semi-reflective element 351, and is partially transmitted and partially reflected to form a first reflected light 44 and a first transmitted light 45.

[0092] Reference Figure 4A It can be seen that the angle θ of the first reflected light 44 is greater than the angle α of the first transmitted light 45. Based on this, the critical angle of the optical waveguide 32 is set to be smaller than θ and greater than α. At this time:

[0093] The first reflected light 44 is transmitted in the optical waveguide 32 by total reflection until reaching the second reflective element 352;

[0094] After the first transmitted light 45 reaches the lower surface of the optical waveguide 32, since α is less than the critical angle of the optical waveguide 32, the first transmitted light 45 is reflected to form the second reflected light 47 and refracted to form the refracted light 46. Therefore, the intensity of the first transmitted light 45 is weakened each time it reaches the surface of the optical waveguide 32. In addition, since α is less than θ, the number of times the first transmitted light 45 reaches the surface of the optical waveguide 32 during the transmission process is much greater than that of the first reflected light 44. Therefore, the energy of the first transmitted light 44 is continuously consumed during the transmission process.

[0095] See also Figure 4B When the first reflected light 44 reaches the second semi-transmissive and semi-reflective element 352, it is partially transmitted to form a second transmitted light 44', and is partially reflected to form a third reflected light 45'. The second transmitted light 44' continues to be transmitted in the optical waveguide in a total reflection manner until it reaches the third reflecting element 353. After the third reflected light 45' reaches the lower surface of the optical waveguide, it is reflected and refracted at the same time, and forms a fourth reflected light 47' and a second refracted light 46', respectively. Similar to the second reflected light 47, the energy of the fourth reflected light 47' is continuously consumed during the transmission process. The optical path of the second transmitted light 44' in the third semi-transmissive and semi-reflective element is similar to the optical path of the first reflected light 44 in the second semi-transmissive and semi-reflective element, and will not be repeated here.

[0096] According to the above description, the total reflected light such as the first reflected light 44 and the second transmitted light 44' transmitted by total reflection only loses energy when passing through the semi-transparent and semi-reflective element during the transmission process. The first transmitted light 45, the third reflected light 45' and other light that are reflected and refracted on the surface of the optical waveguide will lose energy every time they reach the surface of the optical waveguide and the semi-transparent and semi-reflective element. Therefore, the imaging element only needs to filter according to the intensity to extract the total reflected light carrying the fingerprint information.

[0097] See also Figure 5 When the position of the user's finger changes, the reflected light 42 directly enters the optical waveguide for transmission through the third semi-transmissive and semi-reflective element 353. The transmission process of the reflected light 42 is similar to the above, and will not be repeated here.

[0098] This embodiment processes the reflected light by selecting a semi-transparent and semi-reflective array. Since the semi-transparent and semi-reflective elements allow light to partially pass through, the existence of the semi-transparent and semi-reflective array will not hinder the continuous transmission of the reflected light. Therefore, this embodiment can expand the range of the fingerprint imaging area 37 to around all semi-transparent and semi-reflective elements.

[0099] Based on this, the fingerprint imaging module of this embodiment can be provided with multiple fingerprint imaging areas, each fingerprint imaging area corresponds to a semi-transparent and semi-reflective element. Accordingly, the fingerprint imaging module is provided with multiple layers of optical waveguides, and the transmission direction of each layer of optical waveguide is different. When the user places the fingerprint of the finger in any fingerprint imaging area, the reflected light selects a layer of optical waveguide with a corresponding transmission direction for transmission according to the relative position of the fingerprint imaging area and the imaging element, thereby ensuring that the reflected light of each fingerprint imaging area can reach the imaging element.

[0100] In practical applications, by reasonably setting the number and position of the semi-transparent and semi-reflective elements, large-range fingerprint imaging and even full-screen fingerprint imaging can be achieved, which is conducive to meeting different imaging requirements.

[0101] In one embodiment of the present invention, the first light is quasi-parallel light.

[0102] In one embodiment of the present invention, the imaging element is a charge coupled device sensor (CCD), a complementary metal oxide semiconductor sensor (CMOS) or a quantum thin film photoelectric sensor (QD). Among them, the sensitivity, resolution and imaging quality of CCD are better than those of CMOS, and the production cost of CMOS is lower; the photoelectric conversion efficiency of QD is better than that of CMOS and CCD, and its thickness is thinner. In practical applications, users can choose CCD, CMOS or QD as the imaging element according to their needs. It should be noted that the imaging element is not limited to CCD, CMOS or QD, and any element that can convert the reflected light into an electrical signal and then generate a fingerprint image can implement the present invention.

[0103] In one embodiment of the present invention, the fingerprint imaging module further comprises a substrate. The substrate is disposed on a side of the optical waveguide away from the OLED screen, and is used to carry the optical waveguide and the imaging element. The substrate can be an FPC soft board or a PCB hard board, which is not limited in this embodiment.

[0104] In one embodiment of the present invention, a method for obtaining a fingerprint image using the fingerprint imaging module includes: an OLED screen emits a first light ray, the first light ray is reflected by a finger to form a reflected light ray that penetrates the OLED screen; the reflected light ray is reflected by the first reflection surface and then transmitted in the optical waveguide in the form of total reflection; the reflected light ray is reflected when it is transmitted to the second reflection surface, and its transmission direction changes so that it leaves the optical waveguide and reaches the imaging element; the imaging element can obtain a complete fingerprint image through a fingerprint graphic algorithm, and the fingerprint graphic algorithm can be implemented through an existing solution and will not be repeated here.

[0105] Based on the above description of the fingerprint imaging module, the present invention further provides an electronic device; the electronic device includes the fingerprint imaging module of the present invention. Fig. 6A , Figure 6B and Figure 6C , which are schematic diagrams of the structures of the electronic devices described in several different embodiments. When the user places his finger on the fingerprint imaging area 61, the fingerprint imaging module can collect the user's fingerprint information and generate the user's fingerprint image through the imaging element 62. The presence of the optical waveguide enables the position of the imaging element 62 to be adjusted according to actual needs, which is conducive to the flexible layout of the under-screen circuit; the presence of the optical waveguide also enables the position and number of the fingerprint imaging area to be adjusted according to actual needs, which is conducive to meeting different fingerprint imaging needs. In addition, the fingerprint imaging module can expand the range of the fingerprint imaging area by reasonably setting the number and position of the semi-transparent and semi-reflective elements. Therefore, the electronic device described in the present invention can set the size, number, position of the fingerprint imaging area and the position of the imaging element according to actual needs, so as to meet different user needs.

[0106] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0107] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0108] The fingerprint imaging module of the present invention allows the imaging element to be arranged at any position on one side of the optical waveguide, which is conducive to realizing a flexible layout of the under-screen circuit.

[0109] The fingerprint imaging module can combine the first reflection surface, the second reflection surface and the optical waveguide together by coating, which can not only reduce the thickness of the entire module, but also reduce the influence of stray light, which is beneficial to improving the imaging quality.

[0110] The fingerprint imaging module can use the existing OLED screen in the electronic device as a light source. In practical applications, it is only necessary to add an optical waveguide and an imaging element to the existing device to realize user fingerprint imaging. Therefore, the fingerprint imaging module does not need to add additional modules such as light sources, which is conducive to saving costs and reducing assembly requirements.

[0111] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0112] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A fingerprint imaging module, characterized in that: The fingerprint imaging module comprises: The OLED screen is used to emit a first light beam; after the first light beam reaches the finger, it is reflected to form a reflected light beam penetrating the OLED screen; An optical waveguide, disposed on one side of the OLED screen, for transmitting the reflected light by continuous reflection; An imaging element is arranged on a side of the optical waveguide away from the OLED screen, and is used to process the reflected light to obtain a fingerprint image; A first optical element is disposed on a side of the OLED screen close to the optical waveguide, and is used to change the transmission direction of the reflected light so that the reflected light is transmitted in the optical waveguide in a continuous reflection manner; The second optical element is arranged on a side of the OLED screen close to the optical waveguide, and is used to further change the transmission direction of the reflected light transmitted in the optical waveguide, so that the reflected light leaves the optical waveguide and reaches the imaging element.

2. The fingerprint imaging module according to claim 1, characterized in that: The first optical element is a reflective surface and is disposed on the optical waveguide by coating; and / or The second optical element is another reflective surface and is disposed on the optical waveguide in a coating manner.

3. The fingerprint imaging module according to claim 1, characterized in that: The fingerprint imaging module also includes: At least one semi-transmissive and semi-reflective element is disposed between the first optical element and the second optical element, and is used to allow the reflected light transmitted in the optical waveguide and transmitted via the first optical element to pass through at least one of the semi-transmissive and semi-reflective elements and be transmitted to the second optical element.

4. The fingerprint imaging module according to claim 1, characterized in that: The first optical element is a reflective element, a refracting element, a diffractive element or a semi-transmissive and semi-reflective element; and / or The second optical element is a reflective element, a refracting element, a diffractive element or a semi-transmissive and semi-reflective element.

5. The fingerprint imaging module according to claim 1, characterized in that: The first light is quasi-parallel light.

6. The fingerprint imaging module according to claim 1, characterized in that: The reflected light is transmitted in the optical waveguide in a total reflection manner.

7. The fingerprint imaging module according to claim 1, characterized in that: The imaging element is a charge coupled device sensor, a complementary metal oxide semiconductor sensor or a quantum thin film photoelectric sensor.

8. The fingerprint imaging module according to claim 1, characterized in that: The fingerprint imaging module also includes: The substrate is arranged on a side of the optical waveguide away from the OLED screen, and is used for carrying the optical waveguide and the imaging element.

9. An electronic device, characterized in that: The electronic device comprises the fingerprint imaging module according to any one of claims 1 to 8.

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