Method for determining imaging ratio of foldable screen, electronic device, and storage medium

Abstract

A method for determining the imaging ratio of a bendable screen, an electronic device, and a storage medium. The first surface of the bendable screen is suitable for placing an object to be imaged, and the second surface is provided with an image acquisition device. The curvature radius of the first surface of the bendable screen is adjustable. The determination method includes: acquiring a real-time image formed on the image acquisition device; determining the real-time curvature radius of the first surface of the bendable screen according to the real-time image; and calculating the imaging ratio of the bendable screen to the object to be imaged according to the real-time curvature radius and the thickness of the bendable screen. The solution provided by the present invention can determine the imaging ratio of the object to be imaged in real time according to the bending degree of the bendable screen, so as to correct the imaging distortion caused by the change of the optical path in the bent screen, and obtain an image close to the real size of the object to be imaged.

Description

Technical Field

[0001] The present invention relates to the technical field of image processing, and in particular to a method for determining an imaging ratio of a foldable screen, an electronic device, and a storage medium. Background Art

[0002] With the development of information technology, people are increasingly relying on the convenience and comfort provided by electronic products in their daily lives. In recent years, people not only focus on the enrichment and perfection of electronic products, but also gradually begin to pursue the comfort of using electronic products.

[0003] As an emerging technology, flexible screens are rapidly penetrating into the development of major electronic products, such as flexible mobile phones. These emerging electronic products are gradually changing the visual perception and experience that electronic products based on traditional flat screens bring to people.

[0004] With the transition from traditional flat screens to flexible screens, the image processing technology traditionally used for flat screens also needs to be changed accordingly to adapt to the imaging characteristics of flexible screens. Summary of the invention

[0005] The technical problem solved by the present invention is how to determine the imaging ratio of the foldable screen to the object to be imaged, so as to obtain an image close to the real size of the object to be imaged.

[0006] To solve the above technical problem, an embodiment of the present invention provides a method for determining an imaging ratio of a flexible screen, wherein the flexible screen has a first surface and a second surface opposite to each other along a thickness direction, the first surface is suitable for placing an object to be imaged, an image acquisition device is provided on the second surface, and the curvature radius of the first surface of the flexible screen is adjustable. The determination method comprises: acquiring a real-time image of the object to be imaged acquired by the image acquisition device; determining a real-time curvature radius of the first surface of the flexible screen according to the real-time image; and calculating an imaging ratio of the flexible screen to the object to be imaged according to the real-time curvature radius and the thickness of the flexible screen.

[0007] Optionally, determining the real-time curvature radius of the first surface of the flexible screen according to the real-time image includes: determining the real-time curvature radius of the first surface of the flexible screen according to a deformation amount of the real-time image compared with a preset standard image.

[0008] Optionally, determining the real-time curvature radius of the first surface of the flexible screen according to the deformation amount of the real-time image compared with a preset standard image includes: determining the real-time curvature radius of the first surface of the flexible screen according to the ellipticity of the real-time image, wherein the real-time image is elliptical and the preset standard image is circular.

[0009] Optionally, determining the real-time curvature radius of the first surface of the flexible screen according to the ellipsometric ratio of the real-time image includes: the greater the ellipsometric ratio of the real-time image, the smaller the real-time curvature radius of the first surface of the flexible screen.

[0010] Optionally, the first surface of the flexible screen is suitable for contacting fingerprints, the image acquisition device includes a photoelectric sensor module, the photoelectric sensor module is arranged on the second surface of the flexible screen, the light source is arranged in an area inside the flexible screen close to the second surface, the light source is suitable for emitting light signals in different directions toward the first surface of the flexible screen, the light signal is reflected on the first surface of the flexible screen to form reflected light along different directions, and the reflected light passes through the flexible screen and enters the photoelectric sensor module to be received.

[0011] Optionally, the first surface of the flexible screen is convex, and the second surface of the flexible screen is concave, and calculating the imaging ratio of the flexible screen to the object to be imaged based on the real-time curvature radius and the thickness of the flexible screen includes: calculating the imaging ratio according to the following formula: k=2(rh) / r; wherein k is the imaging ratio, r is the real-time curvature radius, h is the thickness, and k, r, and h are all non-negative numbers.

[0012] Optionally, the imaging ratio has a value range of [0, 2].

[0013] Optionally, the first surface of the flexible screen is concave, and the second surface of the flexible screen is convex, and calculating the imaging ratio of the flexible screen to the object to be imaged based on the real-time curvature radius and the thickness of the flexible screen includes: calculating the imaging ratio according to the following formula: k=2r / (rh); wherein k is the imaging ratio, r is the real-time curvature radius, h is the thickness, and k, r, and h are all non-negative numbers.

[0014] Optionally, the imaging ratio has a value range of (2, +∞).

[0015] To solve the above technical problems, an embodiment of the present invention further provides an image processing method, which is used for an electronic device equipped with a flexible screen, wherein the flexible screen has a first surface and a second surface relative to each other along a thickness direction, the first surface is suitable for placing an object to be imaged, and an image acquisition device is provided on the second surface, and the curvature radius of the first surface of the flexible screen is adjustable. The image processing method comprises: acquiring a real-time image of the object to be imaged acquired by the image acquisition device; determining a real-time curvature radius of the first surface of the flexible screen according to the real-time image; calculating an imaging ratio of the flexible screen to the object to be imaged according to the real-time curvature radius and the thickness of the flexible screen; and acquiring an image of the object to be imaged according to the real-time image and the imaging ratio of the flexible screen to the object to be imaged.

[0016] In order to solve the above technical problems, an embodiment of the present invention further provides an electronic device, comprising: a foldable screen, wherein a first surface of the foldable screen along the thickness direction is suitable for placing an object to be imaged; an image acquisition device, which is arranged on a second surface of the foldable screen along the thickness direction, and the second surface is opposite to the first surface; a processor, which is coupled to the foldable screen and the image acquisition device; and a memory, wherein a computer program is stored on the memory, and when the computer program is executed by the processor, the steps of the above method are implemented.

[0017] Optionally, a light source is further included, and the image acquisition device is suitable for acquiring a light signal emitted by the light source and reflected by the first surface of the flexible screen.

[0018] Optionally, the bendable screen includes: a bendable protective layer having a first surface suitable for contacting the object to be imaged; and a display panel, on the first surface of which the bendable protective layer is arranged, and on the second surface of which a photoelectric sensing module is arranged, the display panel includes a plurality of display pixels, and the light source includes one or more display pixels.

[0019] Optionally, the display panel and the image acquisition device are directly bonded together by optical adhesive.

[0020] Optionally, the material of the optical glue is a convertible adhesive.

[0021] In order to solve the above technical problem, an embodiment of the present invention further provides a storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, it is suitable for implementing the steps of the above method.

[0022] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0023] The embodiment of the present invention provides a method for determining the imaging ratio of a bendable screen, wherein the bendable screen has a first surface and a second surface opposite to each other along the thickness direction, the first surface is suitable for placing an object to be imaged, the second surface is provided with an image acquisition device, and the curvature radius of the first surface of the bendable screen is adjustable, and the determination method comprises: acquiring a real-time image of the object to be imaged acquired by the image acquisition device; determining the real-time curvature radius of the first surface of the bendable screen according to the real-time image; and calculating the imaging ratio of the bendable screen to the object to be imaged according to the real-time curvature radius and the thickness of the bendable screen. The scheme provided by the present invention can determine the imaging ratio of the object to be imaged in real time according to the bending degree of the bendable screen, so as to correct the imaging distortion caused by the change of the optical path in the bent screen, and obtain an image close to the real size of the object to be imaged. Specifically, the bendable screen can be imaged based on the total reflection principle of physical optics, and according to the different bending degrees of the bendable screen, a suitable imaging ratio can be determined, and then the real-time image formed on the image acquisition device is corrected to obtain an image that is more in line with the real size of the object to be imaged.

[0024] Furthermore, an embodiment of the present invention also provides an electronic device, comprising: a foldable screen, wherein the first surface of the foldable screen along the thickness direction is suitable for placing an object to be imaged; an image acquisition device, which is arranged on the second surface of the foldable screen along the thickness direction, and the second surface is opposite to the first surface; a processor, which is coupled to the foldable screen and the image acquisition device; a memory, wherein a computer program is stored on the memory, and the steps of the above method are implemented when the computer program is executed by the processor. Thus, while improving the user's comfort based on the foldable screen, during the user's use, according to the current bending degree of the foldable screen of the electronic device, a suitable imaging ratio can be determined in real time to improve the imaging accuracy of the object to be imaged (such as the user's finger) and reduce the degree of distortion. In the optical under-screen fingerprint recognition scenario, the electronic device using the solution described in this embodiment can have a high fingerprint recognition accuracy regardless of the current bending degree of the foldable screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flow chart of a method for determining an imaging ratio of a foldable screen according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of an imaging light path of a light source after being reflected by a flexible screen according to an embodiment of the present invention;

[0027] Figure 3 A schematic diagram of an imaging light path of another light source after being reflected by a flexible screen according to an embodiment of the present invention;

[0028] Figure 4 A schematic diagram of an imaging optical path of a bendable screen according to an embodiment of the present invention;

[0029] Figure 5 is a schematic diagram of an imaging optical path of another bendable screen according to an embodiment of the present invention;

[0030] Figure 6 It is a structural block diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] As mentioned in the background technology, most of the existing optical under-screen image processing technologies are developed based on flat screens. In the flexible screen scenario, due to the bending of the screen, the light path inside the screen will be distorted, resulting in a certain degree of deformation and scaling of the acquired image compared to the object to be imaged. This results in the existing image acquisition device being applied to a flexible screen, and the acquired image is distorted compared to the real image of the object to be imaged. In the optical under-screen fingerprint recognition scenario, such distortion will seriously affect the accuracy of fingerprint recognition.

[0032] To solve the above technical problems, an embodiment of the present invention provides a method for determining an imaging ratio of a flexible screen, wherein the flexible screen has a first surface and a second surface opposite to each other along a thickness direction, the first surface is suitable for placing an object to be imaged, an image acquisition device is provided on the second surface, and the curvature radius of the first surface of the flexible screen is adjustable. The determination method comprises: for any light source in the image acquisition device, obtaining a real-time image formed on the image acquisition device after a light signal emitted by the light source is reflected by the first surface of the flexible screen; determining a real-time curvature radius of the first surface of the flexible screen according to the real-time image; and calculating an imaging ratio of the flexible screen to the object to be imaged according to the real-time curvature radius and the thickness of the flexible screen.

[0033] The solution provided by the present invention can determine the imaging ratio of the object to be imaged in real time according to the bending degree of the bendable screen, so as to correct the imaging distortion caused by the change of the optical path in the bendable screen, and obtain an image close to the real size of the object to be imaged. Specifically, the bendable screen can be imaged based on the total reflection principle of physical optics, and according to the different bending degrees of the bendable screen, a suitable imaging ratio can be determined, and then the real-time image formed on the image acquisition device can be corrected to obtain an image that is more consistent with the real size of the object to be imaged.

[0034] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] Figure 1This is a flow chart of a method for determining an imaging ratio of a foldable screen according to an embodiment of the present invention. The solution described in this embodiment can be applied to an optical under-screen image processing scenario, for example, it can be executed by an electronic device equipped with a foldable screen to obtain an image of an object to be imaged that is in contact with the foldable screen. The object to be imaged can be a finger, and the image can be a fingerprint image.

[0036] Specifically, in this embodiment, the bendable screen may have a first surface and a second surface opposite to each other along the thickness direction, the first surface may be suitable for placing an object to be imaged, the second surface may be provided with an image acquisition device, and the curvature radius of the first surface of the bendable screen is adjustable.

[0037] For example, the first surface may be a side of the electronic device facing the user, and when the user's finger contacts the first surface, the image acquisition device disposed on the second surface may acquire the fingerprint of the finger.

[0038] Specifically, the image acquisition device may include a photoelectric sensor. The flexible screen may perform imaging based on the total reflection principle of physical optics, and the image formed by total reflection of the flexible screen may be captured by the photoelectric sensor.

[0039] More specifically, refer to Figure 1 The determination method in this embodiment may include the following steps:

[0040] Step S101, acquiring a real-time image of the object to be imaged acquired by the image acquisition device;

[0041] Step S102, determining a real-time curvature radius of the first surface of the flexible screen according to the real-time image;

[0042] Step S103, calculating the imaging ratio of the flexible screen to the object to be imaged according to the real-time curvature radius and the thickness of the flexible screen.

[0043] In some embodiments, a light source is provided below the first surface of the flexible screen (“below” here refers to the side of the first surface of the flexible screen close to the image acquisition device, and “above” the first surface of the flexible screen refers to the side of the first surface of the flexible screen close to the object to be imaged), and the image acquisition device is suitable for acquiring a light signal emitted by the light source and reflected by the first surface of the flexible screen. Specifically, the image acquisition device is suitable for acquiring a totally reflected light signal emitted by the light source and formed by total reflection by the first surface of the flexible screen.

[0044] In one embodiment, the light source may be integrated into the image acquisition device. For example, for the image acquisition device disposed on the second surface of the flexible screen, the image acquisition device includes the light source and the photoelectric sensor, wherein the light source may be disposed between the photoelectric sensor and the second surface of the flexible screen.

[0045] In a variation, the light source may be independent of the image acquisition device. For example, the photoelectric sensor module may be disposed on the second surface of the flexible screen, the light source may be disposed in an area inside the flexible screen close to the second surface, the light source is suitable for emitting light signals in different directions toward the first surface of the flexible screen, the light signals are reflected on the first surface of the flexible screen to form reflected light in different directions, and the reflected light passes through the flexible screen and enters the photoelectric sensor module to be received.

[0046] In one embodiment, the bendable screen can perform imaging based on the total reflection imaging principle of physical optics. For example, when the bendable screen is applied to optical under-screen fingerprint recognition, the first surface of the bendable screen can be used to contact the fingerprint, and the photoelectric sensing module of the image acquisition device can be arranged on its second surface. A light source can be arranged inside the bendable screen near its second surface, and the light source can be suitable for emitting light signals in different directions toward the first surface of the bendable screen. The light signal is totally reflected on the first surface of the bendable screen to form totally reflected light in different directions, and the totally reflected light passes through the bendable screen and enters the photoelectric sensing module to be received. Since the intensity of the totally reflected light is modulated by the fingerprint morphology, the image of the fingerprint can be obtained by collecting the totally reflected light emitted from the second surface of the bendable screen.

[0047] In one embodiment, reference Figure 2 When the bending angle of the flexible screen 110 is zero (it can be equivalent to a flat screen at this time), after the light emitted from the light source O irradiates the fingerprint of the finger placed on the first surface 110a of the flexible screen 110, the light received by the photoelectric sensor module 121 disposed on the second surface 110b of the flexible screen 110 is a preset standard image b on the top view as shown in FIG. Figure 2 Specifically, the preset standard image b is a dotted concentric ring-shaped light beam area with the light source O as the origin and the range of Rc to 2Rc' as the radius.

[0048] Where Rc is the critical angle of total reflection θc (θc = sin -1(n1 / n2)) corresponds to the projection length of the circular coordinate r axis; the critical angle of total reflection θc means that among the light emitted from the light source O, the light whose incident angle θ irradiating the first surface 110a is greater than the critical angle of total reflection θc will undergo total reflection; n1 is the refractive index of air, and n2 is the refractive index of the flexible screen 110.

[0049] Where 2Rc' is the critical angle of total reflection φc (φc = sin -1 (n3 / n2)) corresponds to the projection length of the circular coordinate r axis; the critical angle φc of the total reflection angle means that, among the light emitted from the light source O and totally reflected on the first surface 110, the light whose incident angle φ is greater than φc and irradiates the optical glue (not shown) will undergo secondary total reflection; n3 is the refractive index of the optical glue; the optical glue is applied between the light source O and the photoelectric sensor module 121, that is, the optical glue can be used to bond the photoelectric sensor module 121 to the second surface 110b of the flexible screen 110.

[0050] In other words, the preset standard image b formed by the light source O on the foldable screen 110 which is actually a flat screen can be equivalent to a circular ring image. When Rc is small enough, the preset standard image b of the light source O on the flat screen can be equivalent to a circle.

[0051] In one embodiment, reference Figure 3 When the bending angle of the foldable screen 110 is not zero, since both the foldable screen 110 and the photoelectric sensor module 121 are bent, the light emitted by the light source O is Figure 3 The light path inside the curved screen is shown in Figure 2 The light path in the flat screen changes as shown. At this time, the real-time image b' formed by the light source O on the foldable screen 110 which is actually a curved screen can be equivalent to an ellipse.

[0052] Furthermore, as the bending angle of the flexible screen 110 changes, the shape of the elliptical real-time image b′ formed by the light source O on the flexible screen 110 will also change.

[0053] For example, when the foldable screen 110 is Figure 3 and Figure 4 When the foldable screen 110 is bent downward, the short axis of the inner elliptical boundary of the real-time image b' is constant at Rc, and the short axis of the outer elliptical boundary is constant at 2Rc', and the long axes of the two elliptical boundaries change with the bending degree of the foldable screen 110. The greater the bending degree of the foldable screen 110 is, the longer the long axis is.

[0054] For another example, when the foldable screen 110 is Figure 5When the fold is bent upward, the real-time image formed can be equivalent to Figure 3 The real-time image b' is rotated 90 degrees. At this time, the long axis of the inner elliptical boundary of the real-time image is constant at Rc, and the long axis of the outer elliptical boundary is constant at 2Rc'. The short axes of the two elliptical boundaries change with the bending degree of the foldable screen 110. The greater the upward bending degree of the foldable screen 110, the longer the short axis.

[0055] In other words, for light emitted by the same light source, the dark area of ​​the image obtained by reflection from a flat screen (i.e., the area inside a circle with a radius of Rc) is circular; while the dark area of ​​the image obtained by reflection from a curved screen is elliptical, and the degree of ellipse varies with the degree of curvature.

[0056] Therefore, the step S102 may include the step of determining the current bending degree of the flexible screen 110 (i.e., the real-time curvature radius of the first surface 110a of the flexible screen 110) according to the deformation amount of the real-time image b' compared with the preset standard image b. Further, the imaging ratio of the flexible screen 110 to the object to be imaged may be calculated according to the real-time curvature radius.

[0057] For example, the real-time curvature radius of the first surface 110a of the flexible screen 110 may be determined according to the ellipticity of the real-time image b′.

[0058] The ellipticity may be the abbreviation of the eccentricity of an ellipse (also called eccentricity), which is used to define the ratio of the distance from any moving point on the ellipse to the focus of the ellipse to the distance from the moving point to the directrix of the ellipse.

[0059] Specifically, the greater the ellipticity of the real-time image b′ is, the smaller the real-time curvature radius of the first surface 110 a of the flexible screen 110 is.

[0060] In one embodiment, the bending degree of the flexible screen may be characterized based on the real-time curvature radius of the first surface of the flexible screen.

[0061] In one embodiment, each point on the bendable screen has uniform thickness and curvature radius. Accordingly, in step S101, the real-time curvature radius can be determined according to the real-time image of any light source. Furthermore, the thickness of the area can also be determined.

[0062] In a variation, each point on the flexible screen has uneven thickness and curvature radius. Accordingly, in step S101, the real-time curvature radius can be determined based on real-time imaging of a light source closest to the area where the object to be imaged is currently in contact with the flexible screen.

[0063] In one embodiment, reference Figure 4 The first surface 110a of the flexible screen 110 is convex, the second surface 110b of the flexible screen 110 is concave, the first surface 110a is suitable for contacting fingerprints, the second surface 110b is provided with a photoelectric sensor module 121, and a light source O is provided inside the flexible screen 110 near the second surface 110b.

[0064] Furthermore, the bendable screen 110 may include: a bendable protective layer 111, the bendable protective layer 111 having a first surface suitable for contacting the object to be imaged; a display panel 112, the bendable protective layer 111 being arranged on a first surface of the display panel 112, the photoelectric sensor module 121 being arranged on a second surface thereof, a plurality of display pixels being arranged inside the display panel 112 near the second surface thereof, and the light source O including one or more display pixels.

[0065] In some embodiments, the bendable screen 110 may be made of a flexible material to achieve a bendable effect. The photoelectric sensor module 121 may be formed on the bendable substrate in the form of a thin film transistor (TFT). The bendable protective layer 111 may be made of transparent polyimide (CPI).

[0066] In one embodiment, the display panel 112 and the photoelectric sensor module 121 may be directly bonded together by optical glue. Specifically, the material of the optical glue may be a convertible adhesive.

[0067] In one embodiment, the thickness h of the bendable screen 110 may be the sum of the thicknesses of the bendable protective layer 111 and the display panel 112, and the real-time curvature radius r is the real-time curvature radius determined in step S101 and step S102. Then step S103 may include: calculating the imaging ratio according to the formula k=2(rh) / r, wherein k is the imaging ratio, r is the real-time curvature radius, h is the thickness, and k, r, and h are all non-negative numbers.

[0068] Specifically, the imaging ratio k can be used to represent the ratio factor of the fingerprint image collected by the photoelectric sensor module 121 compared to the original fingerprint.

[0069] The derivation process of the calculation formula k = 2 (rh) / r is as follows: Figure 4As shown, the light-emitting point P of the light source O near the second surface 110b of the bendable screen 110 emits light rays PA1 and PA2 in different directions towards the first surface 110a of the bendable screen 110. The two light rays PA1 and PA2 are totally reflected at the interfaces between two adjacent concave grooves and the first surface 110a respectively, and the total reflection light rays A1B1 and A2B2 exit at the second surface 110b of the bendable screen 110 and enter the photoelectric sensing module 121 to be received. The actual distance between the two adjacent concave grooves can be approximately represented by the arc length d1 of the first surface 110a of the bendable screen 110 between points A1 and A2, while the distance between the two adjacent concave grooves in the fingerprint image collected by the photoelectric sensing module 121 can be approximately represented by the arc length 2(d2 - d3) of the second surface 110b of the bendable screen 110 between two light exit points B1 and B2, where d3 is the arc length of the second surface 110b of the bendable screen 110 between the light-emitting point P of the light source O and the normal line QA1, and d2 is the arc length of the second surface 110b of the bendable screen 110 between the light-emitting point P of the light source O and the normal line QA2. Therefore, the ratio of the distance between the two adjacent concave grooves in the image collected by the photoelectric sensing module 121 to the actual distance between the two adjacent concave grooves, that is, the imaging ratio of the bendable screen 110 for fingerprints is k = 2(d2 - d3) / d1 = 2(r - h) / r.

[0070] In some embodiments, the range of the scale factor of the fingerprint image collected by the photoelectric sensing module 121 compared to the original fingerprint is 0 < k < 2. The imaging scale factor k of the bendable screen 110 can be greater than 1, in which case a magnified image of the fingerprint is collected; the imaging scale factor k of the bendable screen 110 can also be less than 1, in which case a reduced image of the fingerprint is collected. Specifically, when r > 2h, 1 < k < 2; when h < r < 2h, 0 < k < 1.

[0071] When the real-time radius of curvature r of the bendable screen 10 approaches positive infinity, that is, when the bendable screen 110 is a flat screen, its imaging ratio is equal to 2.

[0072] In one embodiment, referring to Figure 5 , the first surface 110a of the bendable screen 110 is concave, the second surface 110b of the bendable screen 110 is convex, the first surface 110a is adapted to contact the fingerprint, the photoelectric sensing module 121 is disposed on the second surface 110b, and a light source O is disposed inside the bendable screen 110 near its second surface 110b.

[0073] Furthermore, the bendable screen 110 may include: a bendable protective layer 111, the bendable protective layer 111 having a first surface suitable for contacting the object to be imaged; a display panel 112, the bendable protective layer 111 being arranged on a first surface of the display panel 112, the photoelectric sensor module 121 being arranged on a second surface thereof, a plurality of display pixels being arranged inside the display panel 112 near the second surface thereof, and the light source O including one or more display pixels.

[0074] In one embodiment, the thickness h of the bendable screen 110 may be the sum of the thicknesses of the bendable protective layer 111 and the display panel 112, and the real-time curvature radius r is the real-time curvature radius determined in step S101 and step S102. Then step S103 may include: calculating the imaging ratio according to the formula k=2r / (rh), wherein k is the imaging ratio, r is the real-time curvature radius, h is the thickness, and k, r, and h are all non-negative numbers.

[0075] Specifically, the imaging ratio k can be used to represent the ratio factor of the fingerprint image collected by the photoelectric sensor module 121 compared to the original fingerprint.

[0076] The derivation process of the calculation formula k = 2r / (rh) is as follows: Figure 5 As shown, the light point P of the light source O near the second surface 110b of the flexible screen 110 emits light rays PC1 and PC2 in different directions toward the first surface 110a of the flexible screen 110. The two light rays PC1 and PC2 are totally reflected at the interfaces between two adjacent grooves and the first surface 110a respectively. The totally reflected light rays C1D1 and C2D2 are emitted at the second surface 110b of the flexible screen 110 and enter the photoelectric sensor module 121 to be received. The actual distance between the two adjacent grooves can be approximately represented by the arc length d1 between the two points C1 and C2 of the first surface 110a of the flexible screen 110, and the distance between the two adjacent grooves in the fingerprint image collected by the photoelectric sensor module 121 can be approximately represented by the arc length 2 (d2-d3) between the two light emitting points D1 and D2 of the second surface 110b of the flexible screen 110, wherein d3 is the arc length between the light emitting point P of the light source O and the normal line QC1 of the second surface 110b of the flexible screen 110, and d2 is the arc length between the light emitting point P of the light source O and the normal line QC2 of the second surface 110b of the flexible screen 110. Therefore, the ratio of the distance between the two adjacent grooves in the image collected by the photoelectric sensor module 121 to the actual distance between the two adjacent grooves, that is, the imaging ratio of the fingerprint by the flexible screen 110 is k=2(d2-d3) / d1=2r / (rh).

[0077] In some embodiments, the imaging scale factor of the fingerprint image collected by the photoelectric sensor module 121 is in the range of k>2, that is, it is an enlarged image.

[0078] When the real-time curvature radius r of the flexible screen 110 approaches positive infinity, that is, when the flexible screen 110 is a flat screen, its imaging ratio is equal to 2.

[0079] It should be noted that in Figures 2 to 5 In the method for determining the imaging ratio of the flexible screen of the illustrated embodiment, the thickness of the photoelectric sensor module is ignored, because in most cases, the thickness of the flexible screen is much greater than the thickness of the photoelectric sensor module. If the thickness of the photoelectric sensor module is not negligible, the thickness of the photoelectric sensor module needs to be considered when determining the imaging ratio of the flexible screen.

[0080] An embodiment of the present invention further provides a storage medium storing a computer program, which, when executed by a processor, implements the steps of the method for determining the imaging ratio of the foldable screen of the aforementioned embodiment of the present invention.

[0081] In one embodiment, the storage medium is further adapted to store thickness parameters of each point or region on the flexible screen.

[0082] From the above, the solution of this embodiment can determine the imaging ratio of the object to be imaged in real time according to the bending degree of the bendable screen, so as to correct the imaging distortion caused by the change of the optical path in the bent screen, and obtain an image close to the real size of the object to be imaged. Specifically, the bendable screen can be imaged based on the total reflection principle of physical optics, and according to the different bending degrees of the bendable screen, a suitable imaging ratio can be determined, and then the real-time image formed on the image acquisition device can be corrected to obtain an image that is more consistent with the real size of the object to be imaged.

[0083] An embodiment of the present invention further provides an image processing method for an electronic device equipped with a flexible screen, wherein the flexible screen has a first surface and a second surface relative to each other along a thickness direction, the first surface is suitable for placing an object to be imaged, and an image acquisition device is provided on the second surface, and the curvature radius of the first surface of the flexible screen is adjustable. The image processing method comprises: acquiring a real-time image of the object to be imaged acquired by the image acquisition device; determining a real-time curvature radius of the first surface of the flexible screen according to the real-time image; calculating an imaging ratio of the flexible screen to the object to be imaged according to the real-time curvature radius and the thickness of the flexible screen; and acquiring an image of the object to be imaged according to the real-time image and the imaging ratio of the flexible screen to the object to be imaged.

[0084] The embodiment of the present invention further provides an electronic device, referring to Figure 6 , Figure 6 It is a structural block diagram of an electronic device according to an embodiment of the present invention.

[0085] Specifically, the electronic device 20 may include: a foldable screen 21, wherein a first surface of the foldable screen 21 along the thickness direction is suitable for placing an object to be imaged; an image acquisition device 22, which is arranged on a second surface of the foldable screen 21 along the thickness direction, and the second surface is opposite to the first surface; a processor 23, which is coupled to the foldable screen 21 and the image acquisition device 22; and a memory 24, wherein a computer program is stored on the memory 24, and when the computer program is executed by the processor, the above-mentioned Figures 1 to 5 The steps of the method are shown.

[0086] In one embodiment, reference Figures 2 to 5 The electronic device 20 may have an optical under-screen fingerprint recognition function, and the electronic device 20 further includes a light source, and the image acquisition device is suitable for acquiring a light signal emitted by the light source and reflected by the first surface of the flexible screen. Specifically, the flexible screen 21 (corresponding to Figures 2 to 5 The bendable screen 110) may include: a bendable protective layer 111 having a first surface suitable for contacting the object to be imaged; and a display panel 112, on the first surface of which the bendable protective layer 111 is arranged, and on the second surface of which a photoelectric sensor module 121 is arranged, and a plurality of display pixels are arranged inside the display panel 112 near the second surface thereof, and the light source O includes one or more display pixels.

[0087] Specifically, the image acquisition device 22 may be a photoelectric sensor module 121 .

[0088] Specifically, the bendable screen 21 can perform imaging based on the total reflection principle of physical optics. The structures and functions of the bendable protective layer, the display panel and the photoelectric sensor module can refer to the above Figures 2 to 5 The relevant description in will not be repeated here.

[0089] In one embodiment, when the computer program stored in the memory 24 is executed by the processor 23 Figures 1 to 5 When determining the imaging ratio of the flexible screen as shown, the real-time curvature radius of the flexible screen 21 and the pressing area of ​​the fingerprint on the first surface of the flexible screen 21 can be determined first, and then the thickness of the flexible screen 21 in the pressing area can be determined, and then the imaging ratio can be calculated according to the real-time curvature radius and thickness.

[0090] In one embodiment, when the computer program is executed by the processor, it is also suitable for: implementing the step of correcting the image captured by the image acquisition device 22 according to the determined imaging ratio of the flexible screen 21, so as to obtain an image close to the actual size of the object to be imaged.

[0091] In one embodiment, the components in the electronic device 20 may be made of flexible materials to achieve a bendable effect. For example, the bendable screen 21 may be made of flexible materials, and the image acquisition device 22 may be formed on a bendable substrate in the form of a thin film transistor (TFT).

[0092] Furthermore, the bendable protective layer 111 may be made of transparent polyimide (Colorless Polyimide, CPI for short).

[0093] In one embodiment, the display panel 112 and the image acquisition device 22 may be directly bonded together by optical adhesive. For example, the display panel 112 and the photoelectric sensor module 121 may be directly bonded together by optical adhesive.

[0094] Preferably, the material of the optical glue may be a convertible adhesive.

[0095] In one embodiment, the electronic device 20 may be a mobile phone, a smart bracelet, a wristwatch, etc.

[0096] Thus, while improving the user's comfort based on the foldable screen, during the user's use, according to the current bending degree of the foldable screen of the electronic device, the appropriate imaging ratio can be determined in real time to improve the imaging accuracy of the object to be imaged (such as the user's finger) and reduce the degree of distortion. In the optical under-screen fingerprint recognition scenario, the electronic device using the solution described in this embodiment can have a high fingerprint recognition accuracy regardless of the current bending degree of the foldable screen.

[0097] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A method for determining the imaging ratio of a foldable screen, characterized in that: The bendable screen has a first surface and a second surface opposite to each other in the thickness direction, the first surface is suitable for placing an object to be imaged, the second surface is provided with an image acquisition device, the curvature radius of the first surface of the bendable screen is adjustable, and the determination method comprises: Acquire a real-time image of the object to be imaged acquired by the image acquisition device; Determine a real-time curvature radius of the first surface of the flexible screen according to the real-time image; Calculating an imaging ratio of the object to be imaged by the flexible screen according to the real-time curvature radius and the thickness of the flexible screen; Wherein, determining the real-time curvature radius of the first surface of the flexible screen according to the real-time image comprises: determining the real-time curvature radius of the first surface of the flexible screen according to the deformation amount of the real-time image compared with a preset standard image; Determining the real-time curvature radius of the first surface of the flexible screen according to the deformation amount of the real-time image compared with the preset standard image includes: determining the real-time curvature radius of the first surface of the flexible screen according to the ellipticity of the real-time image, wherein the real-time image is an ellipse and the preset standard image is a circle; Wherein, the first surface of the flexible screen is a convex surface, the second surface of the flexible screen is a concave surface, and the calculating, according to the real-time radius of curvature and the thickness of the flexible screen, the imaging ratio of the flexible screen to the object to be imaged includes calculating the imaging ratio according to the following formula: k=2(rh) / r, wherein k is the imaging ratio, r is the real-time radius of curvature, h is the thickness, and k, r, and h are all non-negative numbers; or, The first surface of the flexible screen is a concave surface, and the second surface of the flexible screen is a convex surface. Calculating the imaging ratio of the flexible screen to the object to be imaged according to the real-time curvature radius and the thickness of the flexible screen includes calculating the imaging ratio according to the following formula: k=2r / (rh), wherein k is the imaging ratio, r is the real-time curvature radius, h is the thickness, and k, r, and h are all non-negative numbers.

2. The determination method according to claim 1, characterized in that: Determining the real-time curvature radius of the first surface of the flexible screen according to the ellipsometric ratio of the real-time image includes: the greater the ellipsometric ratio of the real-time image, the smaller the real-time curvature radius of the first surface of the flexible screen.

3. The determination method according to claim 1, characterized in that: The first surface of the flexible screen is suitable for contacting fingerprints. The image acquisition device includes a photoelectric sensor module and a light source. The photoelectric sensor module is arranged on the second surface of the flexible screen. The light source is arranged in an area inside the flexible screen close to the second surface. The light source is suitable for emitting light signals in different directions toward the first surface of the flexible screen. The light signal is reflected on the first surface of the flexible screen to form reflected light in different directions. The reflected light passes through the flexible screen and enters the photoelectric sensor module to be received to form the real-time image.

4. The determination method according to claim 1, characterized in that: The first surface of the flexible screen is convex, and the second surface of the flexible screen is concave. Calculating the imaging ratio of the flexible screen to the object to be imaged according to the real-time curvature radius and the thickness of the flexible screen includes: calculating the imaging ratio according to the following formula: k=2(rh) / r, wherein k is the imaging ratio, r is the real-time curvature radius, h is the thickness, and k, r, and h are all non-negative numbers; and the value range of the imaging ratio is [0, 2].

5. The determination method according to claim 1, characterized in that: The first surface of the flexible screen is a concave surface, and the second surface of the flexible screen is a convex surface. Calculating the imaging ratio of the flexible screen to the object to be imaged according to the real-time curvature radius and the thickness of the flexible screen includes: calculating the imaging ratio according to the following formula: k=2r / (rh), wherein k is the imaging ratio, r is the real-time curvature radius, h is the thickness, and k, r, and h are all non-negative numbers; and the value range of the imaging ratio is (2, +∞).

6. The determination method according to claim 1, characterized in that: A light source is disposed below the first surface of the flexible screen, and the image acquisition device is suitable for acquiring light signals emitted by the light source and reflected by the first surface of the flexible screen.

7. An image processing method for an electronic device equipped with a foldable screen, characterized in that: The bendable screen has a first surface and a second surface opposite to each other in the thickness direction, the first surface is suitable for placing an object to be imaged, the second surface is provided with an image acquisition device, the curvature radius of the first surface of the bendable screen is adjustable, and the image processing method comprises: According to any one of the determination methods of claims 1 to 6, calculating the imaging ratio of the object to be imaged by the flexible screen; An image of the object to be imaged is acquired according to the real-time image and the imaging ratio of the object to be imaged by the flexible screen.

8. An electronic device, characterized in that: include: A bendable screen, wherein a first surface of the bendable screen along a thickness direction is suitable for placing an object to be imaged; An image acquisition device, disposed on a second surface of the foldable screen along a thickness direction, the second surface being opposite to the first surface; A processor, coupled to the flexible screen and the image acquisition device; A memory having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method according to any one of claims 1 to 7.

9. The electronic device according to claim 8, characterized in that: It also includes a light source, and the image acquisition device is suitable for acquiring a light signal emitted by the light source and reflected by the first surface of the flexible screen.

10. The electronic device according to claim 9, characterized in that: The bendable screen comprises: a bendable protective layer having a first surface suitable for contacting the object to be imaged; and The display panel has the bendable protective layer disposed on its first surface and the photoelectric sensor module disposed on its second surface. The display panel includes a plurality of display pixels, and the light source includes one or more display pixels.

11. The electronic device according to claim 10, characterized in that: The display panel and the image acquisition device are directly bonded together by optical adhesive.

12. The electronic device according to claim 11, characterized in that: The material of the optical glue is a convertible adhesive.

13. A storage medium, characterized in that: The storage medium stores a computer program, which is suitable for implementing the steps of the method according to any one of claims 1 to 7 when executed by a processor.

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