Image acquisition device, its positioning method, and electronic device

Abstract

The present application provides an image acquisition device, its positioning method, and an electronic device, relating to the technical field of display devices. The image acquisition device can be integrated into the electronic device and directly calibrate and position the angular position of planar rotation within the electronic device, so as to be able to adjust to reduce the influence of moiré patterns on the imaging quality of the image acquisition device and improve the imaging accuracy of the image acquisition device. The image acquisition device includes an image sensor for being disposed in a fingerprint recognition area under the display screen, and further includes an angle sensor and a driving mechanism coaxially disposed with the image sensor. Driven by the driving mechanism, the image sensor and the angle sensor rotate coaxially in a plane parallel to the display screen. The image sensor is a fingerprint image sensor for obtaining a fingerprint image of a finger above the display screen through the display screen.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and in particular to an image acquisition device and a positioning method thereof, and an electronic device. Background Art

[0002] As the functions of electronic devices such as mobile phones and tablets become increasingly powerful, higher and higher requirements are placed on the realization of important auxiliary functions in electronic devices, such as taking pictures and fingerprint recognition. For example, the camera function of mobile phones, in addition to continuously requiring the clarity of the captured images, also requires a selfie function integrated under the screen. For example, the fingerprint recognition module is also required to provide accurate and fast fingerprint recognition on the display surface, so as to improve the user experience of electronic devices.

[0003] Taking the optical fingerprint recognition integrated under the screen of an electronic device as an example, it usually includes an image sensor arranged under the screen on the front. The finger covers the area of ​​the screen corresponding to the image sensor, and the fingerprint is illuminated and reflected by the light source of the display screen. The reflected light carrying specific biometric information is received, recorded or analyzed by the image sensor, thereby achieving the function of recording the biometric information or identifying specific biometric information.

[0004] The image sensor is usually set at a preset position in the display area under the display screen. Since the pixel arrangement of the display screen is usually different from that of the image sensor, the image sensor obtains images through the display screen, and the obtained images will have colorful high-frequency irregular stripes, called moiré. Moiré will cause interference with the quality of the obtained images. Because moiré is irregular, it usually has no obvious shape pattern. However, when the image sensor is rotated parallel to the display screen, the moiré will change with the change of the rotation angle between the image sensor and the display screen. Usually, within the rotation range of 360°, an angle position with the lightest moiré can be found. The image sensor and the display screen can form the best imaging quality when they are kept at this angle.

[0005] In the prior art, it is usually necessary to first place the sample of the image sensor on a rotating table under the display screen, rotate it manually and observe the moiré in the image of the image sensor at various angles, so as to determine the angle position with the least moiré and perform subsequent revision proofing. Such an operation is relatively time-consuming to adjust, and since other errors may occur during the actual processing and assembly process, even if the preliminary design and adjustment are accurate, it may still cause serious moiré in the final product. Summary of the invention

[0006] The object of the present application is to provide an image acquisition device, its positioning method, and an electronic device. The image acquisition device can be integrated into the electronic device and directly calibrate the angular position of planar rotation and position within the electronic device, so as to be adjustable to reduce the influence of moiré on the imaging quality of the image acquisition device and improve the imaging accuracy of the image acquisition device.

[0007] The embodiments of the present application are implemented as follows:

[0008] On the one hand, an embodiment of the present application provides an image acquisition device, including an image sensor for being disposed in a fingerprint recognition area below a display screen, and further including an angle sensor and a driving mechanism coaxially disposed with the image sensor. Driven by the driving mechanism, the image sensor and the angle sensor rotate coaxially in a plane parallel to the display screen. The image sensor is a fingerprint image sensor for obtaining a fingerprint image of a finger above the display screen through the display screen.

[0009] Optionally, the image acquisition device of the embodiment of the present application further includes a circuit board disposed below the display screen. The image sensor is disposed on the circuit board, and the fingerprint image acquired by the image sensor is transmitted to the circuit board.

[0010] Optionally, the angle sensor is a potentiometer.

[0011] Optionally, the angle sensor is a gyroscope.

[0012] Optionally, the driving mechanism is a rotating motor.

[0013] Optionally, the rotating motor is a stepper motor.

[0014] Optionally, a reinforcing sheet is disposed on the back side of the circuit board.

[0015] Optionally, the image sensor, the angle sensor, and the driving mechanism are fixed by pasting.

[0016] Optionally, a heat dissipation structure is further disposed between the driving mechanism and the circuit board.

[0017] Optionally, the heat dissipation structure includes a thermal grease layer.

[0018] Optionally, the image acquisition device of the embodiment of the present application further includes a controller, and the controller is electrically connected to the image sensor, the angle sensor, and the driving mechanism respectively. When the image acquisition device further includes a circuit board, the controller is also electrically connected to the circuit board.

[0019] Optionally, a rotation initial position of the image sensor is preset on the rotation path of the driving mechanism, and the controller can control the driving mechanism to drive the image sensor to rotate to the rotation initial position.

[0020] Optionally, a limiting member is further provided on the rotation path of the driving mechanism, and the limiting member is used to limit the rotation position of the driving mechanism.

[0021] Optionally, the controller is electrically connected to the image sensor, the angle sensor, and the driving mechanism respectively through coaxial cables.

[0022] On the other hand, an embodiment of the present application provides an electronic device, including a display screen and the image acquisition device of any one of the foregoing, and the image acquisition device is disposed under the display screen.

[0023] In yet another aspect of the embodiments of the present application, a positioning method for an image acquisition device is provided. The method includes: driving the driving mechanism to drive the image sensor and the angle sensor to rotate coaxially; the image sensor acquires external image information through the display screen at a preset frequency, and the angle sensor acquires the rotation angle information of the driving mechanism corresponding to the shooting position of the external image information at the same preset frequency; analyzing the acquired multiple external image information, determining the external image information with the lowest moiré level as the optimal image information, and matching the rotation angle information corresponding to the optimal image information as the optimal angle; driving the driving mechanism to drive the image sensor and the angle sensor to rotate coaxially to the optimal angle.

[0024] Optionally, analyzing the acquired multiple external image information, determining the external image information with the lowest moiré level as the optimal image information, and matching the rotation angle information corresponding to the optimal image information as the optimal angle includes: comparing the current external image information with the previous external image information, and retaining the external image information with a lower moiré level obtained by the comparison; acquiring the next external image information at the preset frequency, comparing it with the retained external image information with a lower moiré level, and retaining the external image information with a lower moiré level obtained by the comparison; when the rotation angle information reaches the preset maximum angle value, determining the currently retained external image information with a lower moiré level as the optimal image information, and matching the rotation angle information corresponding to the optimal image information as the optimal angle.

[0025] Optionally, a rotation initial position of the image sensor is preset on the rotation path of the driving mechanism; before the driving mechanism drives the image sensor, the circuit board, and the angle sensor to rotate coaxially, the method further includes: driving the driving mechanism to drive the image sensor and the angle sensor to rotate coaxially to the rotation initial position, and resetting the rotation angle information of the angle sensor to zero.

[0026] Optionally, the preset maximum angle value is 360° or 180°.

[0027] An embodiment of the present application provides an image acquisition device and a positioning method thereof, and an electronic device. The image acquisition device includes an image sensor for being arranged below a display screen, the image sensor being used to acquire an external image through the display screen, and also includes an angle sensor and a driving mechanism coaxially arranged with the image sensor. The image sensor, the angle sensor, and the driving mechanism are all coaxially arranged. Driven by the driving mechanism, the image sensor and the angle sensor coaxially rotate in a plane parallel to the display screen. During the rotation process, by analyzing the external images acquired through the display screen at various positions on the rotation path, an image with the smallest influence of moiré on the image can be obtained in the external images at various positions on the entire rotation path, and the image is determined as the desired optimal image. Then, the image acquisition device is rotated to a rotation position corresponding to the optimal image through the driving mechanism for positioning, so that the image acquisition device can be accurately positioned at a position under the screen where the influence of moiré on the image is the smallest. The image acquisition device serves as a fingerprint recognition device in an electronic device, the image sensor is a fingerprint image sensor and is arranged in a fingerprint recognition area under the display screen, the fingerprint image of the finger above the display screen is acquired through the display screen, and the influence of moiré is eliminated as much as possible by adjusting the rotation position, so that the accuracy of the fingerprint image of fingerprint recognition can be higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 This is one of the structural schematic diagrams of an image acquisition device provided in an embodiment of the present application;

[0030] Figure 2 yes Figure 1 A top view of

[0031] Figure 3 This is a second structural schematic diagram of an image acquisition device provided in an embodiment of the present application;

[0032] Figure 4 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application;

[0033] Figure 5 This is one of the flow charts of a positioning method of an image acquisition device provided in an embodiment of the present application;

[0034] Figure 6 This is the second flowchart of a positioning method of an image acquisition device provided in an embodiment of the present application;

[0035] Figure 7 This is the third flowchart of a positioning method for an image acquisition device provided by an embodiment of the present application.

[0036] Icons: 10 - display screen; 20 - circuit board; 21 - image sensor; 30 - angle sensor; 40 - drive mechanism; 50 - reinforcement patch; 60 - controller; 70 - coaxial cable. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application.

[0038] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "inside", "outside", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this application is usually placed during use. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0039] It should also be noted that unless otherwise clearly specified and defined, the terms "set", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0040] In the prior art, an image acquisition device is usually set at a preset position in the display area under the display screen in an electronic device, and the specific position is subject to the image acquisition function required by the image acquisition device. For example, the image acquisition device can be a front camera set under the display screen of the electronic device, which is configured on the display side of the display screen of the electronic device and captures external images through the display screen. Another example is that the image acquisition device can also be a fingerprint recognition device, which is configured at a fixed position of the display screen of the electronic device. When a human body part such as a finger with specific biometric information adheres to the fixed position of the display screen, the fingerprint recognition device can capture the image adhering to the display screen to extract and identify the specific biometric information in the image.

[0041] Hereinafter, the fingerprint recognition device is taken as an example of the image acquisition device for illustration.

[0042] When the image acquisition device is used for fingerprint recognition on the display side of an electronic device, the image acquisition device needs to be arranged under the display screen and is usually located in the display area. The pixel arrangement in the display area of the display screen is different from the pixel arrangement of the image sensor in the image acquisition device. The image quality of the image obtained by the image sensor through the display screen is interfered by different frequency waves (moiré patterns), which will have a greater adverse impact on the accuracy of fingerprint recognition. Since the size of the moiré pattern will change differently with the angular relationship of the relative rotation of the plane between the image sensor and the display screen, an angle with the lowest moiré level can be found on the path of the relative angle rotation between the image sensor and the display screen. Rotating the image acquisition device to this angle with the lowest moiré level can make the imaging quality of the image obtained by the image acquisition device during actual use in the electronic device reach the best.

[0043] In the prior art, usually, the sample of the image acquisition device needs to be set on a turntable, and the display screen of the electronic device to be installed is set above the image acquisition device. Then, the turntable is operated to rotate, and images at various angular positions are continuously obtained during the rotation. After comparing to obtain the angular position where the image with the lowest moiré level is located within the rotation range of 0° - 360° of the turntable, when the image acquisition device is installed in the electronic device subsequently, it is installed at this angular position. However, since the assembly and processing of the electronic device itself include multiple processes, it is inevitable to generate precision errors during the assembly process, resulting in a difference between the designed installation state and the actual installation state. Once such a difference occurs, it is difficult to ensure that the image acquisition device in the installed electronic device is in a position with better imaging quality.

[0044] An embodiment of the present application provides an image acquisition device. Figure 1 It is one of the structural schematic diagrams of an image acquisition device provided by an embodiment of the present application. Figure 2 It is Figure 1 a top view of, and for the sake of clear view and avoiding occlusion, Figure 2 the display screen 10 is hidden in. As Figure 1 and combined with Figure 2 shown, the image acquisition device of the embodiment of the present application includes an image sensor 21 arranged under the display screen 10. The image sensor 21 is used to obtain an external image through the display screen 10, and further includes an angle sensor 30 and a driving mechanism 40 coaxially arranged with the image sensor 21. Driven by the driving mechanism 40, the image sensor 21 and the angle sensor 30 rotate coaxially in a plane parallel to the display screen 10.

[0045] As Figure 1 and Figure 2As shown, the image sensor 21, the angle sensor 30, and the drive mechanism 40 are coaxially arranged. The drive mechanism 40 drives the image sensor 21 and the angle sensor 30 to rotate together. The rotation direction of the drive mechanism 40 is parallel to the plane of the display screen 10. The rotation angle of the drive mechanism 40 can be recorded by the angle sensor 30. Since the rotation direction is parallel to the plane of the display screen 10, the image acquisition device arranged under the display screen 10 only rotates relative to the display screen 10 and does not move the relative position. In this way, the image acquisition device can always obtain external image information through the display screen 10. During the rotation process, the image acquisition device continuously obtains image information in the current state at each angle where it is located. At the same time, the angle sensor 30 also records the rotation angle in the current state. At each rotation angle, the rotation angle is matched with the image information. In the rotation path of 0° - 360°, all the acquired image information can be compared. By comparing the moiré patterns in the image information at each angle, it is possible to obtain the image information with the lowest moiré degree within the entire 0° - 360° rotation range, and obtain the rotation angle where the image information with the lowest moiré degree is obtained. At this time, as long as the drive mechanism 40 is driven again to rotate the image sensor 21 and the angle sensor 30 to the rotation angle position where the image information with the lowest moiré degree is located and fixed without further rotation, the image acquisition device can obtain external images under the display screen 10 and can avoid the influence of moiré to the greatest extent, presenting a better image quality. When the image acquisition device is a fingerprint recognition module, after reducing the influence of moiré as much as possible, the fingerprint recognition ability of the fingerprint recognition module can be improved, and the recognition accuracy can be enhanced.

[0046] Exemplarily, such as Figure 1 and Figure 2 As shown, in this embodiment, the image acquisition device further includes a circuit board 20 arranged under the display screen 10. The image sensor 21 is arranged on the circuit board 20. The external image acquired by the image sensor 21 is transmitted to the circuit board. That is, the image sensor 21 and the circuit board 20 form an image acquisition module. Or, it further includes an optical element above the image sensor 21 to jointly form an image acquisition module. The optical element senses the optical signal, the image sensor 21 is used to acquire images, and the circuit board 20 receives the acquired images and can perform processing operations or storage on the images acquired by the image sensor 21 through the circuit board 20 when the circuit board 20 has processing operation or storage functions.

[0047] It should be noted that in the embodiments of the present application, the implementation form of the circuit board 20 is not specifically limited. The circuit board 20 can be a printed circuit board (PCB). Those skilled in the art should understand that as a support for electronic components and a carrier for realizing electrical connections, a printed circuit board generally refers to a rigid printed board structure. The circuit board 20 can also be a flexible printed circuit (FPC). A flexible printed circuit is a circuit board made of polyimide or polyester film, which has excellent flexibility and reliability. The flexible printed circuit has a high wiring density, a light self-weight, a thin thickness, and can have a certain degree of flexible bending performance. In some special implementation scenarios of the embodiments of the present application, the flexible printed circuit can also be selected. The embodiments of the present application do not specifically limit the material of the circuit board 20, etc. Among them, in the embodiments of the present application, the specific structural form and parameter settings of the image sensor 21 are not specifically limited. As mentioned above, when the image acquisition device in the embodiments of the present application is used for different purposes and acquires images for different purposes, the corresponding structures and parameter settings will have corresponding differences. For example, when the image acquisition device is used as a front camera, corresponding settings and selections are made according to the clarity required for the images captured by the front camera, and relevant influencing factors such as the shooting distance and the clarity of the shooting need to be considered. When the image acquisition device is used for fingerprint recognition, it is necessary to clearly and accurately extract information points of the fingerprint of the finger attached to the surface of the display screen 10 at a short distance. When setting the image sensor 21 correspondingly, characteristic factors such as the acquisition clarity of the near-object image need to be considered.

[0048] In addition, the image sensor 21 applied to an electronic device is usually an overall structure including an image acquisition pixel array and a packaging structure. For example, the image sensor 21 can be a complementary metal oxide semiconductor (CMOS) image sensor. The image acquisition pixel array is a photosensitive pixel array in a two-dimensional plane, and each pixel point includes a photodiode structure capable of performing photoelectric conversion. The packaging structure packages the image acquisition pixel array. After packaging, the image sensor 21 has good structural sealing, which makes the stability of the acquired images better, is not easily disturbed by factors such as light and vibration in the external environment, and the service life of the packaged image sensor 21 is also longer.

[0049] Moreover, in the entire image acquisition device, the circuit board 20, the image sensor 21, and the angle sensor 30 are coaxially arranged and can rotate coaxially under the driving action of the driving mechanism 40, which maximally avoids the risk of the position change or misalignment of the device under the screen during the process of avoiding the influence of rotational adjustment moiré.

[0050] The image acquisition device provided by the embodiment of the present application includes an image sensor 21 arranged below the display screen 10, the image sensor 21 is used to acquire external images through the display screen 10, and also includes an angle sensor 30 and a driving mechanism 40 coaxially arranged with the image sensor 21. The image sensor 21, the angle sensor 30 and the driving mechanism 40 are all coaxially arranged. Under the drive of the driving mechanism, the image sensor 21 and the angle sensor 30 coaxially rotate in a plane parallel to the display screen 10. During the rotation process, by analyzing the external images acquired through the display screen at various positions on the rotation path, the angles of the external images at various positions on the entire rotation path can be obtained. The image with the least effect of moiré on the image is determined as the desired optimal image, and then the image acquisition device is rotated to the rotation position corresponding to the optimal image through the driving mechanism 40 for positioning, so that the image acquisition device can be accurately located at the position under the screen where the effect of moiré on the image is the least. The image acquisition device, as a front camera device in the electronic device, can eliminate the effect of moiré as much as possible by adjusting the rotation position, so that the imaging effect of the captured image can be better. The image acquisition device, as a fingerprint recognition device in the electronic device, can eliminate the effect of moiré as much as possible by adjusting the rotation position, so that the accuracy of fingerprint recognition can be higher.

[0051] Optionally, the angle sensor 30 is a potentiometer, or the angle sensor 30 is a gyroscope.

[0052] A potentiometer is an adjustable electronic component. It consists of a resistor and a rotating or sliding system. When a voltage is applied between the two fixed contacts of the resistor, the position of the contacts on the resistor is changed by the rotating or sliding system, and a voltage having a certain relationship with the position of the moving contact can be obtained between the moving contact and the fixed contact. The potentiometer is arranged in the image acquisition device as an angle sensor 30. During the process of the driving mechanism 40 driving the rotation, it can accurately feedback and record the rotation angle at each position, and reflect the rotation angle through the change of the voltage value. It has high sensitivity, accurate indication, strong anti-interference ability, stable and reliable operation, and the structure of the potentiometer is compact and small. It is arranged in the image acquisition device as an angle sensor 30, which is conducive to the miniaturization design of the image acquisition device and the electronic equipment provided with the image acquisition device.

[0053] As an angular motion detection device, the gyroscope is widely used in the prior art. The gyroscope is an angular motion detection device that uses the momentum of a high-speed rotating body to sense the relative inertial space of the shell around one or two axes orthogonal to the rotation axis. The accuracy and reliability of angle detection can be further guaranteed from the structural point of view. In addition, taking a mobile phone as an electronic device as an example, a gyroscope is usually provided to achieve the corresponding functions. The gyroscope used as the angle sensor 30 in the image acquisition device in this solution can also be shared with other gyroscopes required for other functions in the electronic device through corresponding design.

[0054] Optionally, the driving mechanism 40 is a rotary motor.

[0055] like Figure 1 As shown, the driving mechanism 40 adopts a rotary motor, which has a compact structure and works stably and reliably. By controlling or limiting the uniform rotation speed of the driving mechanism 40, the frame-by-frame shooting of the image sensor 21 can be set accordingly. In this way, for example, the image sensor 21 acquires an image every time it rotates one degree, and no less than 360 images can be acquired between 0°-360°. By comparing and analyzing these 360 ​​images, the image with the lowest degree of moiré is found as the optimal image, and the corresponding rotation angle value matching the optimal image is acquired by the angle sensor 30. By rotating the driving mechanism 40 to the position of the rotation angle value, the optimal acquisition angle of the image sensor 21 can be achieved, the influence of the moiré on the image is minimized, and the image quality is improved.

[0056] Optionally, the rotating motor can be a stepper motor. A stepper motor is an electric motor that converts an electrical pulse signal into a corresponding angular displacement or linear displacement. Each time a pulse signal is input, the rotor rotates an angle or moves forward one step. The angular displacement or linear displacement outputted is proportional to the number of pulses inputted, and the rotation speed is proportional to the pulse frequency. Therefore, a stepper motor is also called a pulse motor. A stepper motor can more accurately control the rotation angle of each step, and cooperate with the image capture action of the image sensor 21 to record the angle signal and obtain image information at each step of rotation pause, so that the action and signal recording of the entire device are more stable.

[0057] Optionally, Figure 3 This is a second structural diagram of an image acquisition device provided in an embodiment of the present application. Figure 3 As shown, a reinforcing sheet 50 is disposed on the back side of the circuit board 20 .

[0058] like Figure 3As shown, generally, the overall structure of the image acquisition device provided in the electronic device is relatively small, and the circuit board 20 is also relatively thin. In order to improve the structural strength of the circuit board 20, a reinforcing sheet 50 can be provided on the back side of the circuit board 20. The reinforcing sheet 50 is usually a thin steel sheet, and the reinforcing sheet 50 and the circuit board 20 can be adhesively bonded by welding. Without having a great impact on the overall structural dimensions and weight of the circuit board 20, the structural strength of the circuit board 20 can be effectively improved.

[0059] Optionally, the image sensor 21, the angle sensor 30, and the driving mechanism 40 are fixedly attached by pasting.

[0060] Exemplarily, the overall structure after welding and encapsulation between the image sensor 21 and the circuit board 20 can be understood as an image acquisition module. The image acquisition module and the angle sensor 30 and the driving mechanism 40 can be fixedly connected by pasting. For example, 3M glue is used to closely fit the three coaxially. Pasting and fixing avoids the setting of other fastening connectors, is convenient for installation, and relative to the non-detachability of welding and fixing, when the structural relationship between the components of the image acquisition device needs to be adjusted, it is also convenient for disassembly.

[0061] Optionally, a heat dissipation structure is further provided between the driving mechanism 40 and the circuit board 20.

[0062] When the driving mechanism 40 is a rotary motor, during the initialization process of the motor or during the driving operation process, heat is usually generated. When the heat cannot be dissipated well, it may cause the rotary motor itself to heat up. For an image acquisition device with a relatively small overall structure, the heat accumulated by the rotary motor may affect the image sensor 21, and even affect the imaging quality of the image acquired by the image sensor 21. Therefore, a heat dissipation structure is provided between the driving mechanism 40 and the circuit board 20, and the heat generated by the driving mechanism 40 is quickly conducted and dissipated through the heat dissipation structure, so as to avoid accumulation at the image acquisition module.

[0063] In the embodiments of the present application, the material, specific setting position, and heat dissipation implementation method of the heat dissipation structure are not specifically limited, as long as heat can be conducted or heat dissipation can be facilitated. Exemplarily, it can be a common heat dissipation method through structural features, such as setting or forming a heat dissipation fin, a heat conduction groove, etc. Also, for example, a coating of a heat conductive material can be selected to improve the heat dissipation effect. Exemplarily, the heat dissipation structure includes a thermal grease layer. The thermal grease layer is coated on the driving mechanism 40 and the position where it contacts the image acquisition module. Through the good heat conduction effect of the thermal grease, the heat is quickly exported and dissipated, avoiding accumulation at the image acquisition module position.

[0064] Optionally, when the image acquisition device according to the embodiment of the present application is used for the fingerprint recognition function under the display screen 10, the image sensor 21 is a fingerprint image sensor, which is used to obtain the fingerprint image of the finger above the display screen 10 through the display screen 10.

[0065] When using an electronic device equipped with the image acquisition device according to the embodiment of the present application for fingerprint recognition, the user only needs to cover the finger on the display screen 10 of the electronic device corresponding to the area for fingerprint recognition. The area for fingerprint recognition refers to the area under the display screen 10 where the fingerprint image sensor is correspondingly set. The fingerprint image sensor obtains the fingerprint image of the finger attached to the display screen 10 through the display screen 10 under the display screen 10. By analyzing and calculating, the fingerprint information in the fingerprint image is captured. Since the characteristic information of the finger patterns of each person is different, the identity of the user can be uniquely confirmed or recognized through the fingerprint information.

[0066] Figure 4 It is a schematic structural diagram of an electronic device provided by an embodiment of the present application. As Figure 4 shown, it includes a display screen 10 and the image acquisition device of any one of the foregoing, and the image acquisition device is arranged under the display screen 10.

[0067] Optionally, the image acquisition device according to the embodiment of the present application further includes a controller 60, and the controller 60 is also electrically connected to the image sensor 21, the angle sensor 30, and the driving mechanism 40 in the image acquisition device respectively.

[0068] As Figure 4 shown, the structure and function implementation of the image acquisition device according to the embodiment of the present application applied to an electronic device will be described below. The electronic device includes a display screen 10 and an image acquisition device arranged under the display screen 10. The image acquisition device further includes a controller 60. The controller 60 is electrically connected to the image sensor 21, the angle sensor 30, and the driving mechanism 40 in the image acquisition device respectively. By controlling the driving mechanism 40 to start through the controller 60, the driving mechanism 40 rotates at a preset speed uniformly (or rotates step by step uniformly), and the image sensor 21 acquires multiple images at various angles. The controller 60 receives the image information of the image sensor 21 and the rotation angle information acquired by the angle sensor 30. In the controller 60, the rotation angle information and the image information at the same position are matched with each other. Moreover, the moiré degree of each image can also be analyzed and evaluated in the controller 60. In the embodiment of the present application, the method for analyzing and evaluating the moiré degree in the image is not specifically limited. By way of example, it can be by comparing the acquired image with a standard image, or by directly finding the moiré characteristics on the acquired image, etc.

[0069] It should be noted that when the image acquisition device according to the embodiment of the present application is used in an electronic device, for example, taking a mobile phone as an example, the controller 60 in the image acquisition device can also adopt the controller 60 used to control the implementation of corresponding functions in the mobile phone. The controller 60 can be the processor chip of the mobile phone. The controller 60 itself includes programs and functions capable of controlling the implementation of various functions in the mobile phone. On this basis, it is further signal-connected to other components in the image acquisition device to implement the corresponding control function.

[0070] In this way, during the process of manufacturing the electronic device according to the embodiment of the present application, the image acquisition device can be directly installed in the electronic device first, and then the existing controller 60 in the electronic device can be used to control and adjust the image acquisition device according to the embodiment of the present application, so that the image acquisition device rotates and adjusts to the position with the lowest moiré degree of the acquired image under the display screen 10, thereby improving the quality of the image acquired by the image acquisition device under the display screen 10.

[0071] Optionally, a rotation initial position of the image sensor 21 is preset on the rotation path of the driving mechanism 40, and the controller 60 can control the driving mechanism 40 to drive the image sensor 21 to the rotation initial position.

[0072] In the electronic device, a rotation initial position for the rotation adjustment of the image acquisition device is provided. The rotation initial position is located on the rotation path of the driving mechanism 40. Before the controller 60 controls the driving mechanism 40 to rotate, first, the driving mechanism is made to drive the image sensor 21 to rotate to the rotation initial position, that is, before each rotation adjustment of the image acquisition device, it returns to the rotation initial position, and the rotation initial position is used as the zero starting point for rotation. This method also facilitates the angle sensor 30 to have a reference and calibration of the initial position when recording the angle information of each rotation position during the rotation adjustment process, improving the accuracy of the adjustment of the image acquisition device by the entire electronic device.

[0073] It should be noted that the initial rotation position set in the electronic device is a definite position point of the image acquisition device in the electronic device. At the same time, it is also an associated point associated with the zero position in the controller 60 and corresponding to the zero position in the controller 60. In principle, this position point can be any point on the rotation path of the image acquisition device in the electronic device, as long as it is associated with the zero position in the controller 60. For the rotation adjustment of the image acquisition device, it all starts from this position point, and the angle sensor 30 also uses this associated point as the starting point for zeroing when recording the rotation angle. Those skilled in the art can make corresponding selections and designs according to actual needs for the specific setting. Setting the initial rotation position also facilitates the angle sensor 30 to determine within the range of 0° - 360° during the entire adjustment process. For example, when the rotation returns to the initial rotation position, it means that the 360° rotation range is completed. If the rotation adjustment does not reach 360°, it may cause the entire adjustment process not to reach the position with the lowest moiré level of the image, and thus it is impossible to find the image with the lowest moiré level. If the rotation adjustment exceeds 360°, it will result in unnecessary repetition of image information acquisition and comparison, wasting system resources and adjustment time.

[0074] Optionally, a limiting member is also provided on the rotation path of the driving mechanism 40, and the limiting member is used to limit the rotation position of the driving mechanism 40.

[0075] Still taking the electronic device as a mobile phone as an example, considering the development of miniaturization and portability of mobile phones, the internal space of mobile phones is very limited. On the basis of integrating multiple intelligent functions, the position for setting the image acquisition device inside the mobile phone is extremely limited, which may make it difficult to reserve enough space to ensure a 360° rotation path after the entire image acquisition device is installed. In this case, the rotation path of the image acquisition device can be set to match the reserved space through the controller 60, or alternatively, the rotation path of the image acquisition device can be limited by setting a limiting member.

[0076] Exemplarily, the rotation path for adjusting the positioning position of the image acquisition device can be set to be at least between 0° and 180°. Due to the symmetry of the image, usually, a rotation position with a relatively low moiré level of the image can also be found within a complete half-turn (180°) range. Therefore, inside the electronic device, a limiting member can be provided on the opposite side of the initial rotation position, that is, a limiting member is provided at the position from the initial rotation position to 180° along the rotation path (since the initial rotation position can, in principle, be any position on the rotation path, and the limiting member only needs to maintain a position relationship on the opposite side of the initial rotation position, and does not need to limit the specific position. Therefore Figure 4(The initial rotation position and the limiting member are not shown in [the figure]), so that after the controller 60 controls the driving mechanism 40 to drive the image acquisition module and the angle sensor 30 to rotate 180°, the entire structure can be physically limited in position by the limiting member, thereby further ensuring that if the controller 60 does not send a stop signal in time, the internal structure of the electronic device can also limit and stop the rotation, avoiding damage to other structures inside the electronic device due to excessive rotation adjustment when the internal space is insufficient.

[0077] Among them, in Figure 4 the initial rotation position and the structure of the limiting member are not shown, and moreover, in the embodiments of the present application, the specific setting position of the initial rotation position on the rotation path, as well as the specific position and the limiting method of the limiting member are not specifically limited, as long as the corresponding requirements and functions for the initial rotation position and the limiting member can be satisfied.

[0078] For example, the limiting member can be configured as a structure for limiting the driving output end of the driving mechanism 40, so that the limiting member can be controlled and limited by the driving starting end of the image acquisition device of the embodiments of the present application, making the control and limiting operations more direct and accurate.

[0079] Optionally, as Figure 4 shown, the controller 60 is electrically connected to the circuit board 20, the controller 60 is electrically connected to the angle sensor 30, and the controller 60 is electrically connected to the driving mechanism 40 through coaxial cables 70 respectively.

[0080] A coaxial cable 70 (Coaxial Cable) refers to a cable with two concentric conductors, and the conductor and the shielding layer share the same axis. The most common coaxial cable 70 is composed of a copper wire conductor isolated by an insulating material. Outside the inner insulating material is another layer of annular conductor and its insulator, and then the entire cable is wrapped by a sheath of polyvinyl chloride or teflon material. The coaxial cable 70 can stretch and rotate relatively freely. Using the coaxial cable 70 to connect the controller 60 to the circuit board 20, the controller 60 to the angle sensor 30, and the controller 60 to the driving mechanism 40 can enable the driving mechanism 40, the circuit board 20, the angle sensor 30, and the image sensor 21 to rotate coaxially without being hindered by conductive connections and can stretch freely. Moreover, the coaxial cable 70 also has the advantages of fast transmission speed and small interference, so as to improve the accuracy of the rotation adjustment and positioning of the image acquisition device in the electronic device.

[0081] Another aspect of the embodiments of the present application provides a positioning method for an image acquisition device. Figure 5 is one of the flowcharts of a positioning method for an image acquisition device provided by the embodiments of the present application. As Figure 5 shown, the method includes:

[0082] S101. The drive mechanism 40 drives the image sensor 21 and the angle sensor 30 to rotate coaxially.

[0083] S102. The image sensor 21 obtains external image information through the display screen 10 at a preset frequency, and the angle sensor 30 obtains the rotation angle information of the drive mechanism 40 corresponding to the shooting position of the external image information at the same preset frequency.

[0084] S103. Analyze the obtained multiple pieces of external image information, determine the external image information with the lowest moiré level as the optimal image information, and match the rotation angle information corresponding to the optimal image information as the optimal angle.

[0085] S104. Drive the image sensor 21 and the angle sensor 30 to rotate coaxially to the optimal angle through the drive mechanism 40.

[0086] The image sensor is adjusted and positioned by using the under-screen positioning method of the image acquisition device of the embodiment of the present application. After the image acquisition device is installed in the electronic device, the driving mechanism 40 first drives the image sensor 21 and the angle sensor 30 to rotate coaxially (it can be understood that the entire image acquisition device rotates under the display screen 10 under the drive of the driving mechanism 40). According to the above description, in order to avoid introducing errors in the positioning process, the coaxial rotation should be carried out in a uniform rotation manner. Preferably, a step-by-step uniform rotation can be selected. During the uniform rotation process, the image sensor 21 works at a preset frequency (for example, frame by frame, or according to the step frequency of the step-by-step uniform rotation at the pause time of each step), and obtains external image information through the display screen 10. Moreover, the angle sensor 30 obtains the corresponding rotation angle position information at the same frequency and time point as the image sensor 21. Taking the specific frequency point as the standard, the external image information obtained at each frequency point is matched with the rotation angle position information. The acquired multiple external image information are analyzed and evaluated. According to the preset analysis and evaluation criteria, the external image information with the lowest degree of moiré among all the received external image information can be obtained, and this external image information is determined as the optimal image information, and the rotation angle information corresponding to the optimal image information is determined as the optimal angle. After the optimal image information and the corresponding optimal angle are determined, the image sensor 21 and the angle sensor 30 are driven to rotate coaxially to this optimal angle by the driving mechanism 40, so that the image acquisition module can be in the optimal position where the moiré problem is generated with the lowest degree when it acquires the image itself. Because this optimal position has been obtained through systematic acquisition and comparison verification, when the driving mechanism 40 drives the image acquisition device to rotate as a whole to this optimal position, the image acquisition device can be directly determined and positioned. In this process, it is no longer necessary to disassemble and install the image acquisition device, so that the confirmation of the rotation angle is more accurate, and the adverse effects of external conditions on the accurate positioning of the image acquisition device in the electronic device are avoided as much as possible.

[0087] Optionally, Figure 6 This is a second flow chart of a positioning method of an image acquisition device provided in an embodiment of the present application. Figure 6 As shown, S103, analyzing the obtained multiple external image information, determining the external image information with the lowest moiré degree as the optimal image information, and matching the rotation angle information corresponding to the optimal image information as the optimal angle includes:

[0088] S1031, comparing the current external image information with the previous external image information, and retaining the external image information with a lower moiré degree obtained by comparison;

[0089] S1032. Obtain the next external image information at a preset frequency, compare it with the retained external image information with a lower moiré pattern degree, and retain the external image information with a lower moiré pattern degree obtained from the comparison;

[0090] S1033. When the rotation angle information reaches the preset maximum angle value, determine the currently retained external image information with a lower moiré pattern degree as the optimal image information, and match the rotation angle information corresponding to the optimal image information as the optimal angle.

[0091] When analyzing and evaluating multiple pieces of obtained external image information to determine the optimal image information, if waiting to obtain all the external image information at each angular position on the entire rotation path before performing the analysis and evaluation, it requires relatively high storage and computing resources for the controller 60, and the entire positioning process will take a long time due to the analysis and evaluation. Therefore, the process of rotational adjustment and obtaining external images can be combined with the analysis and evaluation process.

[0092] First, the driving mechanism 40 drives the entire image acquisition device to rotate, and the image sensor 21 and the angle sensor 30 acquire external image information and the current angular position information at a preset frequency. When the external image information and the angular position information are acquired at the current position, compare the currently acquired external image information with the previously acquired external image information, and retain the external image information with a lower moiré pattern degree obtained from the comparison of the two external image information, that is, an analysis and evaluation of the acquired external image information is completed during the adjustment process. For example, the external image information with a higher moiré pattern degree obtained from the comparison can be directly discarded. Of course, according to needs, it can also be selected to be retained and stored.

[0093] As the rotation progresses, continue to obtain the next external image information at the preset frequency, then compare the obtained next external image information with the retained external image information with a lower moiré pattern degree in the previous analysis and evaluation, and retain the external image information with a lower moiré pattern degree among them. Similarly, the external image information with a higher moiré pattern degree obtained from the comparison can be directly discarded. Repeat the pairwise analysis and evaluation in this way, and use the time of rotation and external image information acquisition to complete each analysis and evaluation.

[0094] When the rotation angle information reaches the preset maximum angle value, that is, the entire rotation path of 360° or 180° rotation is completed, and all external image information and rotation angle information are acquired during this rotation path. The corresponding comparison and evaluation have been basically completed, and the lowest external image information of the moiré pattern program retained during the entire comparison process is obtained. The retained external image information with a lower moiré pattern degree is determined as the optimal image information, and the rotation angle information corresponding to the optimal image information is matched as the optimal angle. This method can effectively utilize the rotation adjustment time for analysis and comparison, and pairwise analysis and comparison save system computing resources. If the information that does not need to be retained after comparison is directly discarded, it can also save system storage resources.

[0095] Optionally, Figure 7 is the third flowchart of a positioning method for an image acquisition device provided by an embodiment of the present application. As Figure 7 shown, a rotation initial position of the image sensor 21 is preset on the rotation path of the driving mechanism 40.

[0096] S101. Before the driving mechanism 40 drives the image sensor 21 and the angle sensor 30 to rotate coaxially, the method further includes:

[0097] S100. The driving mechanism 40 drives the image sensor 21 and the angle sensor 30 to rotate coaxially to the rotation initial position, and zeroes the rotation angle information of the angle sensor 30.

[0098] When a rotation initial position of the image sensor 21 is also preset on the rotation path of the driving mechanism 40 in the electronic device, before driving the rotation through the driving mechanism 40, the under-screen positioning method of the embodiment of the present application first drives the rotation to the rotation initial position through the driving mechanism 40, and at the rotation initial position, zeroes the rotation angle information of the angle sensor 30, so that the angle sensor 30 starts recording the rotation angle information from 0° with the rotation initial position as the rotation starting point.

[0099] The under-screen positioning method of the image acquisition device of the embodiment of the present application can perform rotation adjustment to achieve the positioning and determination of the optimal under-screen position after the image acquisition device is installed in the electronic device. Moreover, for example, when the fingerprint recognition of the electronic device of the embodiment of the present application is inaccurate after long-term use, or the image quality of the front camera image is poor, or when the electronic device is affected by external factors such as being bumped or impacted, the user can actively trigger an operation to re-perform under-screen positioning adjustment on the image acquisition device again.

[0100] In addition, according to factors such as the internal structure of the electronic device, the specific usage requirements of the image acquisition device, and the setting position, those skilled in the art can set the preset maximum angle value of the rotation adjustment in the under-screen positioning method to 360° or 180° according to actual needs, and determine the rotation path according to the preset maximum angle value set in advance. In addition, the preset frequencies for the image sensor 21 and the angle sensor 30 to obtain their respective information during the rotation process can also be set accordingly in advance.

[0101] The above description is only for the embodiments of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An image acquisition device, characterized in that, It includes an image sensor for setting a fingerprint recognition area under the display screen, and also includes an angle sensor and a driving mechanism coaxially arranged with the image sensor. Driven by the driving mechanism, the image sensor and the angle sensor rotate coaxially in a plane parallel to the display screen. A limiting member is also arranged on the rotation path of the driving mechanism, and the limiting member is used to limit the rotation position of the driving mechanism; the driving mechanism drives the image sensor and the angle sensor to rotate coaxially to the angle corresponding to the fingerprint image with the lowest moiré level. The image sensor is a fingerprint image sensor, which is used to obtain the fingerprint image of the finger above the display screen through the display screen.

2. The image acquisition device according to claim 1, wherein It also includes a circuit board arranged under the display screen. The image sensor is arranged on the circuit board, and the fingerprint image obtained by the image sensor is transmitted to the circuit board.

3. The image acquisition device according to claim 1, characterized in that, The angle sensor is a potentiometer or a gyroscope.

4. The image acquisition device according to claim 1, characterized in that, The driving mechanism is a rotary motor.

5. The image acquisition device according to claim 4, wherein The rotary motor is a stepping motor.

6. The image acquisition device according to claim 2, wherein A reinforcing sheet is arranged on the back side of the circuit board.

7. The image acquisition device according to any one of claims 1-5, characterized in that, The image sensor, the angle sensor and the driving mechanism are fixed by pasting.

8. The image acquisition device according to any one of claims 2-5, characterized in that, There is also a circuit board arranged under the display screen, and a heat dissipation structure is also arranged between the driving mechanism and the circuit board.

9. The image acquisition device according to claim 8, wherein The heat dissipation structure includes a thermal grease layer.

10. The image acquisition device according to any one of claims 1-5, characterized in that, It also includes a controller, which is electrically connected to the image sensor, the angle sensor and the driving mechanism respectively. When the image acquisition device also includes a circuit board, the controller is also electrically connected to the circuit board.

11. The image acquisition device according to claim 10, characterized in that, A rotation initial position of the image sensor is preset on the rotation path of the driving mechanism, and the controller can control the driving mechanism to drive the image sensor to rotate to the rotation initial position.

12. The image acquisition device according to claim 10, wherein The controller is electrically connected to the image sensor, the angle sensor and the driving mechanism respectively through coaxial cables.

13. An electronic device, characterized in that, It includes a display screen and an image acquisition device according to any one of claims 1-12, and the image acquisition device is arranged under the display screen.

14. A positioning method for an image acquisition device, characterized in that, The method includes: The driving mechanism drives the image sensor and the angle sensor to rotate coaxially. The image sensor obtains external image information through the display screen at a preset frequency, and the angle sensor obtains the rotation angle information of the driving mechanism corresponding to the shooting position of the external image information at the same preset frequency. Analyze the obtained multiple pieces of external image information, determine the external image information with the lowest moiré level as the optimal image information, and match the rotation angle information corresponding to the optimal image information as the optimal angle. Drive the image sensor and the angle sensor to rotate coaxially to the optimal angle through the driving mechanism.

15. The positioning method of the image acquisition device according to claim 14, characterized in that, The analyzing the obtained multiple pieces of external image information, determining the external image information with the lowest moiré level as the optimal image information, and matching the rotation angle information corresponding to the optimal image information as the optimal angle includes: Compare the current external image information with the previous external image information, and retain the external image information with a lower moiré pattern degree obtained from the comparison; Obtain the next external image information at a preset frequency, compare it with the retained external image information with a lower moiré pattern degree, and retain the external image information with a lower moiré pattern degree obtained from the comparison; When the rotation angle information reaches the preset maximum angle value, determine the currently retained external image information with a lower moiré pattern degree as the optimal image information, and match the rotation angle information corresponding to the optimal image information as the optimal angle.

16. The positioning method of the image acquisition device according to claim 14, characterized in that, There is a rotation initial position of the image sensor preset on the rotation path of the drive mechanism; Before the drive mechanism drives the image sensor and the angle sensor to rotate coaxially, the method further includes: The drive mechanism drives the image sensor and the angle sensor to rotate coaxially to the rotation initial position, and zeroes the rotation angle information of the angle sensor.

17. The positioning method of the image acquisition device according to claim 15, characterized in that, The preset maximum angle value is 360° or 180°.

Images