Camera module calibration method

Abstract

The invention provides a camera module calibration method. The camera module calibration method comprises the following steps: acquiring an analytic force change curve of a to-be-calibrated camera module; adjusting the position and inclination amount of an image sensor assembly of the camera module relative to a lens according to the analytic force change curve, so that the image sensor assembly reaches the optimal sensing position and alignment state relative to the lens; obtaining an analytic force change curve of the to-be-calibrated camera module again, and determining whether the adjustment effect meets the calibration requirement or not; and if the adjustment effect meets the calibration requirement, recording and storing the adjusted position data of the image sensor assembly and the lens. According to the camera module calibration method, AA equipment does not need to be adopted, a hardware structure special for calibration operation does not need to be additionally arranged in the calibrated camera module either, the hardware requirement for calibration of the camera module is lowered, the calibration operation process is simplified, and reduction of the manufacturing cost and improvement of the production efficiency are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of camera module assembly, and in particular to a camera module calibration method. Background Art

[0002] The camera module is used in electronic devices with shooting functions to shoot images or videos. The camera module generally includes an anti-shake drive unit, a focus drive unit, a chip and a lens. The anti-shake drive unit is used to drive the lens or chip to move in a plane perpendicular to the optical axis of the lens, so that the position between the lens and the chip changes, thereby achieving lens shake compensation and further achieving camera module anti-shake. The focus drive unit drives the lens or chip to move along the optical axis of the lens, so that the relative position between the lens and the chip changes, thereby achieving camera module focus.

[0003] Resolution is a core technical indicator of the camera module, and the tilt between the lens and the chip is the main factor that leads to reduced camera resolution. In the production process of camera modules, in order to strictly control the tilt, AA (Active Alignment) equipment is usually used to adjust the tilt. The AA device clamps the lens and moves it along the optical axis of the lens and the photosensitive center of the photosensitive chip to defocus, determine the tilt between the lens and the chip, and then adjust the lens movement on the X, Y, and Z axes to make the optical axis of the lens and the imaging surface of the chip perpendicular to each other. AA equipment can correct tilt well, but AA equipment has the disadvantages of being expensive and bulky.

[0004] Therefore, it is necessary to provide a low-cost technical solution for adjusting the inclination between the optical axis of the lens and the imaging surface of the chip. Summary of the invention

[0005] The present invention proposes a camera module calibration method, which does not require the use of expensive and bulky AA equipment, can be implemented through simpler and cheaper hardware equipment, and is easy to operate and easy to calibrate the image sensor component and lens in the camera module.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A camera module calibration method, characterized in that it comprises the following steps:

[0008] S1, obtaining a resolution change curve of a camera module to be calibrated;

[0009] S2, adjusting the position and tilt of the image sensor assembly of the camera module relative to the lens according to the resolution change curve, so that the image sensor assembly reaches an optimal sensing position and alignment state relative to the lens;

[0010] S3, obtaining the resolution change curve of the camera module to be calibrated again to determine whether the adjustment effect meets the calibration requirements;

[0011] S4, if the adjustment effect meets the calibration requirements, the position data of the adjusted image sensor assembly and the lens are recorded and stored.

[0012] In some embodiments, step S1 comprises:

[0013] The image sensor assembly is controlled to move along the optical axis direction of the lens by the axial adjustment assembly of the camera module. During the movement, the image sensor assembly senses the image captured by the lens and generates a corresponding image signal; at the same time, the position change of the image sensor assembly relative to the lens is detected to generate a corresponding position signal;

[0014] A resolution change curve is drawn according to the corresponding relationship between the resolution of the image signal and the position signal.

[0015] In some implementations, drawing a resolution change curve according to the corresponding relationship between the resolution of the image signal and the position signal includes:

[0016] The central area of ​​the field of view of the lens is defined as the zero field of view, the edge area outside the zero field of view is defined as the outer field of view, and the outer field of view detection point is selected in the outer field of view;

[0017] An image signal generated by the image sensor component sensing an image captured through the zero field of view is defined as a zero field of view image signal, and an image signal generated by the image sensor component sensing an image captured through the external field of view detection point is defined as an external field of view image signal;

[0018] A zero-field-of-view resolution change curve is drawn according to the corresponding relationship between the resolution of the zero-field-of-view image signal and the position signal, and an external-field-of-view resolution change curve is drawn according to the corresponding relationship between the resolution of the image signal of the external-field-of-view detection point and the position signal.

[0019] In some embodiments, step S2 comprises:

[0020] Determine the optimal sensing position of the image sensor assembly relative to the lens according to the zero field of view resolution change curve, and move the image sensor assembly to the optimal sensing position;

[0021] Determine the inclination of the edge area of ​​the image sensor assembly relative to the central area through the external field resolution change curve;

[0022] The edge area of ​​the image sensor assembly is controlled to move by the axial adjustment assembly to adjust the tilt of the edge area of ​​the image sensor assembly so that the image sensor assembly is parallel to the imaging plane of the lens.

[0023] In some embodiments, step S3 includes:

[0024] Again, a zero-field-of-view resolution change curve is plotted according to the corresponding relationship between the resolution of the zero-field-of-view image signal and the position signal, and an external-field-of-view resolution change curve is plotted according to the corresponding relationship between the resolution of the image signal of the external-field-of-view detection point and the position signal;

[0025] The abscissa of the highest point of the zero field resolution change curve obtained again is compared with the abscissa of the highest point of the outside field resolution change curve, and whether the adjustment effect meets the calibration requirements is determined based on the comparison result.

[0026] In some embodiments, step S4 includes:

[0027] The position data of the image sensor assembly and the lens, as well as the relative position data of each area of ​​the image sensor assembly and the lens are recorded and stored.

[0028] In some embodiments, the method further comprises the following steps:

[0029] S5, reassembling the lens according to the adjusted position data of the image sensor assembly and the lens.

[0030] In some embodiments, step S5 comprises:

[0031] Fix the image sensor assembly according to the position data recorded in step S4;

[0032] Remove the lens from the housing of the camera module and apply glue to the housing;

[0033] Reinstall the lens into the housing for bonding, so that the position of the lens after bonding is consistent with the position data recorded in step S4;

[0034] The glue is cured to secure the lens in the housing.

[0035] In some embodiments, the method further comprises the following steps:

[0036] If it is determined in step S3 that the adjustment effect does not meet the calibration requirements, then return to step S2, and repeat step S2 and step S3 until the adjustment effect meets the calibration requirements.

[0037] In some embodiments, the method further comprises the following steps:

[0038] S0, perform preliminary assembly, signal connection and preliminary calibration on the camera module to be calibrated, so that the camera module is connected to the control unit, and the geometric center of the imaging area of ​​the image sensor component of the camera module is aligned with the optical axis of the lens of the camera module.

[0039] The beneficial effects of the present invention are:

[0040] Compared with the prior art, the camera module calibration method of this embodiment does not need to use AA equipment, but can adjust the relative position of the image sensor assembly and the lens through the axial adjustment component built into the camera module. Most of the current camera modules must be equipped with a corresponding axial adjustment component to drive the image sensor assembly to move along the optical axis of the lens and adjust the inclination of the image sensor assembly relative to the optical axis of the lens. When the camera module calibration method of this embodiment is used to calibrate the existing camera module, it is not necessary to add an additional hardware structure dedicated to the above-mentioned calibration operation in the calibrated camera module. Therefore, the camera module calibration method of this embodiment reduces the hardware requirements for calibrating the camera module, simplifies the calibration operation process, and helps to reduce manufacturing costs and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but should not be construed as limiting the present invention. In the accompanying drawings:

[0042] Figure 1 A schematic diagram of the hardware environment for implementing the camera module calibration method provided in the preferred embodiment of the present invention.

[0043] Figure 2 for Figure 1 The overall structural diagram of the camera module is shown.

[0044] Figure 3 for Figure 1 The cross-sectional structure diagram of the camera module shown.

[0045] Figure 4 for Figure 1 The combined structure diagram of the camera module is shown.

[0046] Figure 5 for Figure 1 In the camera module shown, a schematic diagram of the position changes of the lens and image sensor components before and after adjustment by the camera module calibration method provided by the preferred embodiment of the present invention.

[0047] Figure 6 for Figure 1 A schematic diagram of the partial structure of the support base of the camera module shown.

[0048] Figure 7 for Figure 1 A schematic structural diagram of the second elastic component of the camera module shown.

[0049] Figure 8 A flowchart of a camera module calibration method provided for a preferred embodiment of the present invention.

[0050] Fig. 9 for Figure 1 In the camera module shown, a schematic diagram of the lens edge resolution change curve before and after adjustment by the camera module calibration method provided by the preferred embodiment of the present invention.

[0051] Notes on the attached drawings:

[0052] 10. A second elastic component;

[0053] 101. Focus driving component;

[0054] 11. outer frame; 12. middle frame; 13. inner frame; 14. elastic cantilever; 15. elastic structure; 151. first connecting block; 152. second connecting block; 153. elastic frame; 154. connecting piece;

[0055] 20. housing; 21. bottom plate; 22. mounting plate;

[0056] 30. bracket; 31. cover plate portion; 32. frame portion; 321. assembly window;

[0057] 40. Image sensor assembly; 41. Chip carrier plate; 42. Carrier frame; 43. Chip;

[0058] 49. Position detection unit;

[0059] 51. first coil; 52. magnetic member; 53. second coil;

[0060] 60. Support seat; 61. Support block;

[0061] 70. Sliding structure; 71. Ball bearing; 72. Groove;

[0062] 80. a first elastic component;

[0063] 90. Magnetic components;

[0064] 100, lens; 101, focus drive assembly; 102, optical axis;

[0065] 110. control unit; 111. drive module; 112. controller;

[0066] 120. Test components;

[0067] 130. Camera module;

[0068] 140. The resolution change curve of the lens at zero field of view;

[0069] 150. The resolution change curve of the lens's external field of view before calibration;

[0070] 160. The resolution change curve of the lens's external field of view after calibration. DETAILED DESCRIPTION

[0071] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0072] A preferred embodiment of the present invention discloses a camera module calibration method, which is used to calibrate the installation position of the image sensor assembly and the lens in the camera module before assembling the camera module, so that the imaging surface of the image sensor assembly can achieve good vertical alignment with the optical axis of the lens. In order to more clearly understand the implementation principle of the camera module calibration method, the hardware environment required to implement the camera module calibration method is first specifically introduced below.

[0073] The camera module calibration method is applicable to Figures 1 to 4 The camera module 130 shown is specifically used to first calibrate the installation positions of the image sensor assembly 40 and the lens 100 before assembling the image sensor assembly 40 and the lens 100 of the camera module 130. In this way, in the subsequent assembly, as long as the image sensor assembly 40 and the lens 100 are fixedly assembled at the calibrated installation positions, the tilt between the image sensor assembly 40 and the lens 100 can be effectively eliminated, so that the imaging surface of the image sensor assembly 40 can be well vertically aligned with the optical axis of the lens 100, so that the camera module 130 has good optical performance.

[0074] Please see first Figures 1 to 5 In this embodiment, the hardware required for the camera module calibration method includes a test member 120, a position detection unit 49, an axial adjustment component, a translation adjustment component, and a control unit 110. The test member 120 has a specific optical test pattern, which is used to be arranged opposite to the lens 100 in the camera module 130 during the calibration operation, and is arranged on the optical axis of the lens 100, so that the camera module 130 can capture a test image.

[0075] The position detection unit 49 is used to obtain the relative position of the image sensor assembly 40 and the lens 100 in real time; the position detection unit 49 is integrated in the camera module 130 and installed on one side of the image sensor assembly 40. Specifically, in this embodiment, the position detection unit 49 can be a Hall sensor, which is used to detect and determine the position of the image sensor assembly 40 relative to the lens 100 in real time; the number of the position detection unit 49 is preferably multiple, and can be arranged at intervals in multiple areas of the image sensor assembly 40 to respectively detect and determine the positions of multiple areas of the image sensor assembly 40 relative to the lens 100. The axial adjustment component and the translational adjustment component are also integrated in the camera module 130 and can be arranged to surround the periphery of the image sensor component 40. The axial adjustment component is used to drive the image sensor component 40 to move during the calibration operation so that the geometric center of the imaging area of ​​the image sensor component 40 is tilted relative to the optical axis 102 of the lens 100. It is also used to drive the image sensor component 40 to move along the optical axis 102 of the lens 100 to obtain the edge resolution change curve of the lens 100; the translational adjustment component is used to drive the image sensor component 40 to move in a plane perpendicular to the optical axis 102 of the lens 100 during the calibration operation. Those skilled in the art will understand that since the camera module in the prior art generally may include a driving mechanism for driving its image sensor component to move in multiple directions, and may also include a position detection component for determining the relative position of its image sensor component and its lens, the axial adjustment component, the translational adjustment component, and the position detection unit 49 used in the camera module calibration method of this embodiment may be respectively served by the driving mechanism (such as a focusing mechanism and an anti-shake mechanism) for driving the image sensor component 40, and the position detection component (such as a Hall sensor or other types of position sensors for determining the position of the image sensor component 40 and the lens 100) already existing in the calibrated camera module 130. That is to say, the axial adjustment component, the translational adjustment component, and the position detection unit 49 may be directly integrated into the camera module 130 to be calibrated.

[0076] The control unit 110 is used to control the action of the axial adjustment component and / or the translation adjustment component based on the image signal generated by the camera module 130 shooting the test component 120 and the position signal sensed by the position detection unit 49 during the calibration process. The control unit 110 includes a controller 112 and a drive module 111. The controller 112 can be a data processing device such as a microcomputer, a single-chip microcomputer, etc. The drive module 111 is a connecting component for providing electrical connection for the camera module 130. The image sensor component 40, the position detection unit 49, the translation adjustment component and the axial adjustment component are all electrically connected to the controller 112 through the drive module 111. The controller 112 can drive the camera module 130 to work through the drive module 111.

[0077] As described above, the axial adjustment assembly can be used to drive the image sensor assembly 40 along the optical axis direction of the lens 100, for example Figures 1 to 4 The test component 120 moves relative to the Z-axis direction shown in the figure, so that the controller 112 obtains the edge resolution curve of the camera module 130 during the movement, and analyzes the inclination between the optical axis of the lens 100 and the imaging area of ​​the image sensor assembly 40 according to the edge resolution curve.

[0078] Afterwards, the controller 112 can further control the axial adjustment assembly according to the tilt amount, so that the axial adjustment assembly drives the image sensor assembly 40 to tilt relative to the optical axis 102 of the lens 100 until the optical axis 102 of the lens 100 is perpendicular to the imaging area of ​​the image sensor assembly 40. Figure 5 , Figure 5 The positional relationship between the optical axis 102 of the lens 100 and the imaging area of ​​the image sensor assembly 40 before and after adjustment is shown respectively.

[0079] After the optical axis 102 of the lens 100 is perpendicular to the imaging area of ​​the image sensor assembly 40, it can be considered that the lens 100 and the image sensor assembly 40 are in the ideal assembly position. At this time, the controller 112 can obtain the position information of the lens 100 and the image sensor assembly 40 respectively, and the driving module 111 can control the axial adjustment assembly 50 and the translation adjustment assembly according to the position information, and drive the image sensor assembly 40 and the lens 100 to move to the position corresponding to the position information of the lens 100 and the image sensor assembly 40 obtained by the controller 112 in the camera module 130, that is, the above-mentioned ideal assembly position, and then the lens 100 and the image sensor assembly 40 can be fixedly assembled respectively to ensure that the optical axis 102 of the assembled lens 100 is perpendicular to the imaging area of ​​the image sensor assembly 40.

[0080] Compared with the prior art, the camera module calibration method provided in this embodiment adopts an axial adjustment component built into the camera module 130 to drive the image sensor component 40 to move, so that the imaging area of ​​the image sensor component 40 is perpendicular to the optical axis 102 of the lens 100, and obtains the position information of the ideal assembly position where the image sensor component 40 and the lens 100 are located at this time. In this way, the image sensor component 40 and the lens 100 can be fixed to the ideal assembly position corresponding to the position information according to the position information, so that the assembled camera module 130 has good optical performance. Those skilled in the art can understand that among the hardware used in the camera module calibration method disclosed in this embodiment, the axial adjustment component and the translation adjustment component for adjusting the position of the image sensor assembly 40, and the position detection unit 49 for determining the relative position of the image sensor assembly 40 and the lens 100 can all be hardware contained in the camera module 130 to be calibrated, without the need to use an expensive and bulky AA (Active Alignment) device to move the lens 100 to correct the position between the lens 100 and the image sensor assembly 40; and the test component 120 and the control unit 110 do not require expensive costs and large sizes. Therefore, compared with the prior art, the hardware required for the camera module calibration method provided in this embodiment is smaller in size, lower in cost, and easier to operate.

[0081] Next, the specific structure of the camera module 130 suitable for calibration by the camera module calibration method, that is, the applicable object of the camera module calibration method, is further explained.

[0082] Please refer again Figure 2 , Figure 3 and Figure 4 The camera module 130 includes a lens 100, a focus driving member 101, a housing 20, a bottom plate 21, a bracket 30, a first coil 51, a magnet component 52, a second coil 53, a mounting plate 22, and the above-mentioned image sensor assembly 40 and a position detection unit 49. The bracket 30, the first coil 51, and the magnet component 52 together constitute the above-mentioned axial adjustment assembly, and the magnet component 52, the second coil 53, and the mounting plate 22 together constitute the above-mentioned translation adjustment assembly, that is, the axial adjustment assembly and the translation adjustment assembly adopted in this embodiment can share the magnet component 52, which is conducive to further miniaturization and simplification of hardware.

[0083] The bottom port of the shell 20 is open, and the bottom plate 21 is arranged at the bottom port of the shell 20, which is used to close the bottom port of the shell 20, thereby forming a relatively closed inner cavity in the shell 20. The image sensor assembly 40, the axial adjustment assembly, the translation adjustment assembly, and the position detection unit 49 are installed in the inner cavity of the shell 20. The top surface of the shell 20 is also provided with an assembly hole connected to the inner cavity. The focus drive 101 can be a voice coil motor, which is preferably installed on the top surface of the shell 20 and corresponds to the position of the assembly hole. The lens 100 is assembled in the assembly hole and is connected to the focus drive 101 in transmission. The focus drive 101 can be used to drive the lens 100 to move up and down along the optical axis of the lens 100, thereby changing the distance between the lens 100 and the image sensor assembly 40, and completing the focus of the camera module 130.

[0084] In this embodiment, the optical axis 102 of the lens 100 is arranged to be parallel to the Z-axis direction shown in the figure. When the camera module 130 is used to capture an image, the external light passes through the lens 100 along the Z-axis direction and finally reaches the image sensor assembly 40, causing the photosensitive component in the image sensor assembly 40 to generate a corresponding image signal, thereby finally causing the camera module 130 to form an image.

[0085] As mentioned above, the axial adjustment assembly includes a bracket 30, a first coil 51 and a magnet component 52. The bracket 30 includes a frame portion 32 surrounding the periphery of the image sensor assembly 40, and the frame portion 32 is spaced apart from the image sensor assembly 40. The magnet component 52 is fixed to the inner side of the frame portion 32, and the first coil 51 is fixed to a position on the image sensor assembly 40 corresponding to the magnet component 52. After the first coil 51 is energized, the interaction force generated by the first coil 51 and the magnet component 52 drives the image sensor assembly 40 to tilt relative to the optical axis 102 of the lens 100 or move along the optical axis 102 of the lens 100.

[0086] In this embodiment, the number of magnet components 52 is four, and the four magnet components 52 are arranged at equal intervals around the image sensor assembly 40. Specifically, the frame portion 32 is in the shape of a square frame, and the four magnet components 52 are respectively arranged on the four side walls of the frame portion 32. More specifically, the four side walls of the frame portion 32 are each provided with a hollow assembly window 321, and the four magnet components 52 are respectively embedded in the four assembly windows 321 of the frame portion 32. In this way, there is no barrier between the magnet component 52 and the first coil 51, so as to avoid the barrier from weakening the interaction force effect generated by the magnet component 52 and the first coil 51.

[0087] The number of magnet components 52 is the same as the number of first coils 51; the positions of each magnet component 52 and each first coil 51 correspond to each other. Each magnet component 52 forms a power supply group with the corresponding first coil 51, and the working process of each power supply group is independent of each other. Based on the electromagnetic thrust, each power supply group provides a force to each side of the image sensor assembly 40 in a direction parallel to the optical axis 102 of the lens 100 (i.e., the Z-axis direction shown in the figure), so that the axial adjustment assembly can be used to drive the image sensor assembly 40 as a whole to move forward and backward along the direction of the optical axis 102 of the lens 100, and further, by changing the direction and magnitude of the force of each power supply group on the image sensor assembly 40, the forces on each side of the image sensor assembly 40 are different, so that the image sensor assembly 40 is tilted relative to the optical axis 102 of the lens 100. For example, when the power supply group corresponding to the left side of the image sensor assembly 40 provides a larger force toward the positive direction of the Z axis (i.e., the upper direction shown in the figure) to the left side, and the power supply group corresponding to the right side of the image sensor assembly 40 provides a smaller force toward the positive direction of the Z axis to the right side, the left side will move a greater distance toward the positive direction of the Z axis than the right side, so that the image sensor assembly 40 tilts toward the right side of the optical axis 102. Alternatively, when the power supply group corresponding to the left side provides a force toward the positive direction of the Z axis to the left side, and the power supply group corresponding to the right side provides a force toward the negative direction of the Z axis to the right side, the left side moves toward the positive direction of the Z axis, while the right side moves toward the negative direction of the Z axis, so that the image sensor assembly 40 can be tilted to a greater extent toward the right side of the optical axis 102. Through the above principle, the image sensor assembly 40 can be controlled to tilt at any angle relative to the optical axis 102, and the existing angular error of the image sensor assembly 40 relative to the optical axis 102 can be compensated by this means.

[0088] Please also read Figure 6 and Figure 7 In this embodiment, the camera module 130 further includes a first elastic component 80, a second elastic component 10, and a support base 60. The first elastic component 80, the second elastic component 10, and the support base 60 are also disposed inside the housing 20.

[0089] In this embodiment, the inner space 31 of the bracket 30 is used to accommodate the support seat 60; the support seat 60 is slidably abutted against the inner wall of the bracket 30 through a plurality of sliding structures 70. When the support seat 60 moves, the support seat 60 slides along the bottom wall of the bracket 30 through the sliding structures 70, so that the movement process of the axial adjustment assembly and the translation adjustment assembly is more stable.

[0090] In this embodiment, the support seat 60 includes a rectangular bottom frame and four support blocks 61 protruding from the same side of the bottom frame, and the four support blocks 61 are respectively arranged at the four corners of the bottom frame, corresponding to the four corners of the bracket 30. The sliding structure 70 includes four grooves 72 respectively opened on the top surface of the support block 61, and each groove 72 is provided with at least one ball 71; the upper side of the ball 71 is exposed above the corresponding groove 72 and abuts against the cover portion 31.

[0091] In this embodiment, the support seat 60 is disposed at the bottom of the inner cavity of the housing 20, and the bottom frame is fixedly connected to the top surface of the middle frame 12 (described in detail later) of the second elastic component 10. After the support seat 60 moves in the XY plane shown in the figure, the middle frame 12 can drive the support seat 60 to return to its original position. The first elastic component 80 includes four elastic sheets, one end of each of which is fixedly connected to the four support blocks 61; the other end of each of the four elastic sheets is fixedly connected to the image sensor component 40.

[0092] In other embodiments, the number of support blocks 61 can be appropriately increased or decreased according to actual needs. As long as it can support the image sensor assembly 40 through the first elastic component 80, so that the image sensor is suspended. For example, the number of support blocks 61 can be one, two, three, or five or more. In other embodiments, the number of elastic sheets can be appropriately increased or decreased, as long as it can suspend the image sensor assembly 40 on the support block 61.

[0093] The first elastic component 80 can be composed of common elastic components in the industry, but it must ensure that it can suspend the image sensor component 40 on the support block 61, and after the image sensor component 40 is tilted relative to the support seat 60, that is, after it is tilted relative to the optical axis 102 of the lens 100, use its own deformation elastic force to force the image sensor component 40 to return to its original position. For example, the first elastic component 80 can be a spring wire.

[0094] As mentioned above, the translation adjustment assembly includes a magnet component 52, a second coil 53 and a mounting plate 22, wherein the mounting plate 22 is in a square frame shape, the number of the second coils 53 is four, and they are fixedly connected to the inner wall of the mounting plate 22, and the four second coils 53 are arranged around the periphery of the frame portion 32 at equal intervals with the frame portion 32, and the positions of the second coils 53 and the magnet components 52 correspond one by one; the mounting plate 22 is fixedly connected to the inner wall of the housing 20. The interaction force generated by the second coils 53 and the magnet components 52 based on the electromagnetic thrust drives the support seat 60 to move in the XY plane determined by the X-axis and the Y-axis shown in the figure.

[0095] Specifically, the translation adjustment assembly is connected to the support seat 60 to drive the support seat 60 to move in a plane perpendicular to the optical axis 102 of the lens 100, that is, in the XY plane shown in the figure. Specifically, the XY plane shown in the figure is perpendicular to the optical axis 102 of the lens 100, and the translation adjustment assembly drives the support seat 60 to move in the XY plane. The support seat 60 drives the image sensor assembly 40 to move in the XY plane, changes the relative position between the imaging area of ​​the image sensor assembly 40 and the optical axis 102 of the lens 100, and realizes the anti-shake of the camera module 130. Each magnetic component 52 and the corresponding second coil 53 form a power supply group, and the working process of each power supply group is independent of each other. In this way, by changing the force of each power supply group on the outer side of the support seat 60 parallel to the XY plane, the side edges of the support seat 60 are subjected to different forces in the XY plane, so that the image sensor assembly 40 can be driven to move in the XY plane through the support seat 60. The second elastic component 10 is connected to the support base 60 . After the support base 60 moves in a plane perpendicular to the optical axis 102 of the lens 100 , the deformation elastic force of the second elastic component 10 can be used to force the support base 60 to return to its original position.

[0096] See also Figure 7 In this embodiment, the second elastic component 10 can be an elastic circuit board, including an inner frame 13, an intermediate frame 12 spaced around the periphery of the inner frame 13, and an outer frame 11 spaced around the periphery of the intermediate frame 12. The inner frame 13 is connected to the intermediate frame 12 in a suspended manner through an elastic cantilever 14; the intermediate frame 12 is connected to the outer frame 11 in a suspended manner through an elastic connection structure 15; wherein the elastic cantilever 14 is extended along the edge contour of the inner frame 13, one end of the elastic cantilever 14 is connected to the outer frame 11, and the other end thereof is connected to the inner frame 13.

[0097] Furthermore, the outer frame 11 is fixed to the bottom plate 21 of the shell 20; the inner frame 13 is connected to the middle frame 12 in suspension through the elastic cantilever 14; the middle frame 12 is connected to the outer frame 11 in suspension through the elastic connection structure 15. The elastic cantilever 14 is extended along the edge contour of the inner frame 13, one end of the elastic cantilever 14 is connected to the outer frame 11, and the other end is connected to the inner frame 13. Such a structure can increase the torque of the elastic cantilever 14, making the elastic cantilever 14 easy to deform, so that the inner frame 13 is easy to drive. Secondly, compared with the spring wire, the elastic cantilever 14 has a simpler structure and a low manufacturing cost.

[0098] In one application scenario, during the process of assembling the camera module 130, if the imaging surface of the image sensor assembly 40 is not perpendicular to the optical axis of the camera module 130, that is, there is an angle deviation, the image sensor assembly 40 can be driven by the axial adjustment assembly 50 to tilt the image sensor assembly 40 relative to the support seat 60 to compensate for the original angle deviation until the imaging surface of the image sensor assembly 40 is perpendicular to the optical axis of the camera module 130. When the imaging surface of the image sensor assembly 40 is perpendicular to the optical axis of the camera module 130, the position sensor 49 is used to obtain the position parameters of the lens 100 and the image sensor assembly 40 and the position parameters are fed back to the control unit 110. The control unit 110 calculates the tilt amount of the image sensor assembly 40 according to the position parameters, and adjusts the installation position of the first elastic assembly 80 on the support seat according to the tilt amount. Finally, when the first elastic assembly 80 supports the image sensor assembly 40, the position of the image sensor assembly 40 is just located at the ideal position corresponding to the aforementioned position parameters. At this time, the imaging area of ​​the image sensor assembly 40 is well perpendicular to the optical axis 102 of the lens.

[0099] Compared with the prior art, this embodiment uses an axial adjustment component built into the camera module 130 to replace the traditional AA device to adjust the relative position of the image sensor component 40 and the lens 100, which has the advantages of simple structure and low cost.

[0100] In another application scenario, during the operation of the camera module 130, the axial adjustment component can also be used to drive the image sensor component 40 to tilt relative to the support base 60, so that the imaging surface of the image sensor component 40 is set at an angle to the optical axis of the camera module 130, and finally the image sensor component 40 generates a special photosensitive signal, allowing the smart electronic device to obtain special image effects, such as obtaining a fantasy effect of deformed and distorted images.

[0101] From the foregoing description, it is not difficult to find that the axial adjustment component of this embodiment can not only assist in assembling the camera module 130 during the assembly stage of the camera module 130, but also enable the camera module 130 to generate a special photosensitive signal when the camera module 130 is working, thereby having the advantage of diversified functions.

[0102] Based on the hardware environment and applicable objects described above, the camera module calibration method provided by the preferred embodiment of the present application can be implemented. Fig. 9 The camera module calibration method provided in the preferred embodiment of the present application may include the following steps:

[0103] S0, perform preliminary assembly, signal connection and preliminary calibration of the camera module to be calibrated.

[0104] In this implementation, step S0 may include the following operations:

[0105] The various components of the above-mentioned camera module 130 are preliminarily assembled according to the specific assembly method as described above.

[0106] The preliminarily assembled camera module 130 is arranged at a position that can be used to shoot the test component 120 , so that the test component 120 is arranged opposite to the lens 100 in the camera module 130 and arranged on the optical axis of the lens 100 .

[0107] The image sensor assembly 40 , the position detection unit 49 , the translation adjustment assembly and the axial adjustment assembly in the camera module 130 are all electrically connected to the controller 112 via the driving module 111 .

[0108] The image sensor assembly 40 is controlled to move by the control unit 110, preferably by the controller 112 via the driving module 111 and the translation adjustment assembly to control the image sensor assembly 40 to move in the XY plane shown in the figure, so that the geometric center of the image sensor assembly 40 is aligned with the optical axis 102 of the lens 100. The specific process of this operation may include: first, the image sensor assembly 40 is controlled by the controller 112 via the driving module 111 and the translation adjustment assembly to perform a trial movement in any direction in the XY plane shown in the figure, and the image sensor assembly 40 will continuously shoot the test component 120 and generate an image signal of the test component 120 during the movement. After acquiring the image signal, the control unit 110 may determine whether the geometric center of the imaging area of ​​the image sensor assembly 40 is aligned with the optical axis 102 of the lens 100 by various existing technical means, for example, it may be determined that the geometric center of the imaging area of ​​the image sensor assembly 40 is aligned with the optical axis 102 of the lens 100 when the clarity of the image signal reaches the best, or it may be determined that the geometric center of the imaging area of ​​the image sensor assembly 40 is aligned with the optical axis 102 of the lens 100 when the similarity between the image signal and the front reference image of the test component 120 captured in advance and stored in the controller 112 is the highest, etc. When it is determined that the geometric center of the imaging area of ​​the image sensor assembly 40 is aligned with the optical axis 102 of the lens 100, the control unit 110 may control the translation adjustment assembly to maintain the current working state unchanged, so that the position of the image sensor assembly 40 in the XY plane remains unchanged, that is, the state of aligning the geometric center of the imaging area of ​​the image sensor assembly 40 with the optical axis 102 is maintained.

[0109] It can be understood that if the camera module has been preliminarily assembled and calibrated according to the prior art and has established a signal connection with the existing data processing equipment in the previous manufacturing process, then step S0 can be omitted and the method flow of this embodiment can be started directly from the following step S1.

[0110] S1, obtaining a resolution change curve of a camera module to be calibrated.

[0111] In this implementation, step S1 may include the following specific operations:

[0112] The controller 112 controls the image sensor assembly 40 to move back and forth along the direction of the optical axis 102 of the lens 100 (that is, along the Z-axis direction shown in the figure) through the driving module 111 and the axial adjustment assembly, that is, to perform a defocusing movement; during the movement, the image sensor assembly 40 continuously senses the image of the test component 120 captured by the lens 100 and generates a corresponding image signal; at the same time, the position detection unit 49 detects the position change of the image sensor assembly 40 relative to the lens 100 in real time and generates a corresponding position signal. The control unit 110 obtains the image signal and the position signal in real time, and draws a resolution change curve of the lens 100 according to the corresponding relationship between the resolution of the image signal and the position signal.

[0113] In this embodiment, in order to obtain a good calibration effect, the control unit 110 acquires the image signal and the position signal in real time, and draws the resolution change curve of the lens 100 according to the corresponding relationship between the image signal and the position signal, which specifically includes the following operations:

[0114] A central area of ​​a preset area ratio in the field of view of the lens 100 is defined as a zero field of view, and an edge area of ​​the field of view outside the zero field of view is defined as an outer field of view; and outer field of view detection points are selected in the outer field of view, the number of which is at least three, preferably four in this embodiment, and are spaced around the zero field of view, preferably spaced at equal intervals.

[0115] During the movement of the image sensor assembly 40, the image signal generated by the image sensor assembly 40 sensing the image captured through the zero field of view of the lens 100 is defined as a zero field of view image signal, and the image signals generated by the image sensor assembly 40 sensing the images captured through multiple external field of view detection points of the lens 100 are respectively defined as multiple external field of view image signals. It can be understood that the zero field of view image signal is generated in the central area of ​​the image sensor assembly 40, and the multiple external field of view image signals are generated in multiple edge areas of the image sensor assembly 40.

[0116] According to the corresponding relationship between the resolution of the zero-field image signal and the position signal, a zero-field resolution change curve of the lens 100 is plotted, and according to the corresponding relationship between the resolution of multiple external-field image signals and the position signal, multiple external-field resolution change curves of the lens 100 are plotted respectively. Fig. 9, wherein a zero-view resolution change curve 140 and four outer-view resolution change curves 150 / 160 are shown, wherein the horizontal coordinates of the zero-view resolution change curve 140 and the four outer-view resolution change curves 150 / 160 are the defocus amount determined according to the position of the image sensor assembly 40 relative to the lens 100, and the vertical coordinates are the resolution of the image signal. In this step S1, the zero-view resolution change curve 140 of the lens 100 and the four outer-view resolution change curves 150 before the tilt of the image sensor assembly 40 is adjusted are first obtained.

[0117] S2, adjusting the position and tilt of the image sensor component of the camera module relative to the lens according to the resolution change curve, so that the image sensor component reaches an optimal sensing position and alignment state relative to the lens.

[0118] In this embodiment, step S2 may include the following specific operations:

[0119] The optimal sensing position of the image sensor assembly 40 relative to the lens 100 is determined according to the zero field of view resolution change curve 140 of the lens 100, and the image sensor assembly 40 is moved to the optimal sensing position. Specifically, the point with the largest ordinate on the zero field of view resolution change curve 140 (hereinafter referred to as the highest point) represents the highest resolution that can be achieved at zero field of view, so it can be considered that the highest point of the zero field of view resolution change curve 140 corresponds to the optimal sensing position of the image sensor assembly 40 relative to the lens 100. Accordingly, the axial adjustment assembly is controlled to move the image sensor assembly 40 as a whole to a position where the defocus amount is equal to the horizontal coordinate of the highest point of the zero field of view resolution change curve 140. More specifically, it can be so that the position of the central area of ​​the image sensor assembly 40 corresponding to the zero field of view satisfies that the defocus amount is equal to the horizontal coordinate of the highest point of the zero field of view resolution change curve 140, which can be regarded as moving the image sensor assembly 40 to the optimal sensing position.

[0120] After the image sensor assembly 40 is moved to the optimal sensing position, the tilt amounts of the edge areas of the image sensor assembly 40 relative to the central area are determined respectively through the multiple external field resolution change curves 150 before adjustment. Figure 8As shown, among the four external field of view resolution change curves 150 before adjustment, the horizontal coordinates of the points with the largest vertical coordinates (hereinafter referred to as the highest points) on two external field of view resolution change curves 150 are smaller than the horizontal coordinate of the highest point of the zero field of view resolution change curve 140, indicating that the two external field of view detection points corresponding to the two external field of view resolution change curves 150 can obtain the highest resolution when the defocus amount of the image sensor component 40 is smaller than the horizontal coordinate of the highest point of the zero field of view resolution change curve 140; therefore, it can be inferred that the actual defocus amount of the two edge areas of the image sensor component 40 aligned with the two external field of view detection points is greater than the horizontal coordinate of the highest point of the zero field of view resolution change curve 140, so that it can be confirmed that the two edge areas are tilted away from the focus of the lens 100. Similarly, the horizontal coordinates of the highest points on the other two external field resolution change curves 150 are greater than the horizontal coordinates of the highest point of the zero field resolution change curve 140, indicating that the two external field detection points corresponding to the two external field resolution change curves 150 can obtain the highest resolution when the defocus amount of the image sensor assembly 40 is greater than the horizontal coordinate of the highest point of the zero field resolution change curve 140; it can be inferred that the actual defocus amount of the two edge areas of the image sensor assembly 40 aligned with the two external field detection points is less than the horizontal coordinate of the highest point of the zero field resolution change curve 140, so that it can be confirmed that the two edge areas are tilted toward the focus of the lens 100. Based on the above principle, according to the specific coordinate differences between each external field resolution change curve 150 and the zero field resolution change curve 140, the specific tilt amount of each edge area of ​​the image sensor assembly 40 relative to the optical axis 102 of the lens 100 can be calculated. The specific calculation method can refer to the prior art and will not be repeated here.

[0121] After determining the specific inclination amount of each edge area of ​​the image sensor assembly 40 relative to the optical axis 102 of the lens 100, the axial adjustment assembly is controlled based on the determined inclination amount to drive each edge of the image sensor assembly 40 to move respectively to adjust the inclination amount of each edge area of ​​the image sensor assembly 40, so as to eliminate the inclination amount of each edge area relative to the optical axis 102 of the lens 100, so that the image sensor assembly 40 is as accurately perpendicular to the optical axis 102 of the lens 100 as possible, that is, parallel to the imaging surface of the lens 100, so that the image sensor assembly 40 reaches the best alignment state relative to the lens 100.

[0122] S3, obtaining the resolution change curve of the camera module to be calibrated again to determine whether the adjustment effect meets the calibration requirements.

[0123] In this embodiment, step S3 may include the following operations:

[0124] After the tilt adjustment operation of the image sensor assembly 40 as described in step S2, referring to the operation of step S1, the zero field of view resolution change curve 140 of the lens 100 is obtained again, and four external field of view resolution change curves 160 after the tilt adjustment of the image sensor assembly 40 are obtained.

[0125] The horizontal coordinate of the highest point of the external field resolution change curve 160 after adjusting the tilt of the image sensor assembly 40 is compared with the horizontal coordinate of the highest point of the zero field resolution change curve 140, and whether the adjustment effect meets the calibration requirements is determined based on the comparison result. Fig. 9 As shown, the horizontal coordinate of the highest point of the adjusted external field resolution change curve 160 is substantially coincident with the horizontal coordinate of the highest point of the zero field resolution change curve 140, that is, the difference in the horizontal coordinates does not exceed the preset threshold value, indicating that during the movement of the image sensor assembly 40, the resolution change trend of the external field image signal generated by each edge region thereof is substantially consistent with the resolution change trend of the zero field image signal generated by its central region. Therefore, it can be inferred that the defocus amount of each edge region generating the external field image signal in the image sensor assembly 40 during the movement is substantially consistent with the defocus amount of the central region generating the zero field image signal during the movement, which indicates that each edge region of the image sensor assembly 40 has been adjusted to be substantially on the same plane as the central region that is perpendicular to the optical axis 102 of the lens 100, that is, parallel to the imaging surface of the lens 100. At this time, it can be regarded that the image sensor assembly 40 has reached the best alignment state relative to the lens 100, that is, the adjustment effect meets the calibration requirements.

[0126] It can be understood that if step S3 determines that the adjustment effect does not meet the calibration requirements, the process may return to step S2 and repeat steps S2 and S3 until the adjustment effect meets the calibration requirements.

[0127] S4, if the adjustment effect meets the calibration requirements, the position data of the adjusted image sensor assembly and the lens are recorded and stored.

[0128] The step S4 of this embodiment may include the following operations: the control unit 110 detects and determines the relative positions of each area of ​​the image sensor assembly 40 and the lens 100 in real time through the position detection unit 49, and records and stores them; at the same time, the real-time three-dimensional coordinates of the image sensor assembly 40 and the lens 100 are located by, for example, existing technical means, and recorded and stored. In other words, the real-time three-dimensional coordinates of the image sensor assembly 40 and the lens 100, i.e., their own position data, and the relative position data of each area of ​​the image sensor assembly 40 and the lens 100 are recorded and stored. Obviously, the position data recorded and stored in the step S4 corresponds to the best position for the image sensor assembly 40 and the lens 100 to obtain the best imaging effect, including the respective own positions of the image sensor assembly 40 and the lens 100 and the relative position between the two.

[0129] After step S4, the camera module calibration method of this embodiment can be considered to be completed; however, in practical applications, in order to adapt to actual process requirements, the camera module calibration method of this embodiment can further include the following steps:

[0130] S5, reassembling the lens according to the adjusted position data of the image sensor assembly and the lens.

[0131] The step S5 described in this embodiment may include the following operations: after the step S4, first fix the image sensor assembly 40 according to the position data recorded in the step S4, and keep the image sensor assembly 40 fixed at the best self-position recorded in the step S4; then remove the lens 100 from the housing 20, apply glue to the corresponding part of the housing 20, and then reinstall the lens 100 into the housing 20 for bonding, so that the self-position of the lens 100 after bonding and its relative position with the image sensor assembly 40 are consistent with the position data recorded in the step S4, that is, they are respectively in the best self-position and the best relative position recorded in the step S4, and finally cure the glue to fix the lens 100 in the housing 20, so that the image sensor assembly 40 reaches the best initial assembly state relative to the lens 100, that is, the image sensor assembly 40 as a whole is in a plane perpendicular to the optical axis 102 of the lens 100 (such as the XY plane shown in the figure). Next, other assembly work of the camera module 130 can be completed according to the prior art.

[0132] Compared with the prior art, the camera module calibration method of this embodiment does not need to use AA equipment, but can adjust the relative position of the image sensor assembly 40 and the lens 100 through the axial adjustment assembly built into the camera module 130. Most of the current camera modules must be equipped with a corresponding axial adjustment assembly to drive the image sensor assembly to move along the optical axis of the lens and adjust the inclination of the image sensor assembly relative to the optical axis of the lens. When the camera module calibration method of this embodiment is used to calibrate the existing camera module, it is not necessary to add an additional hardware structure dedicated to the above-mentioned calibration operation in the calibrated camera module. Therefore, the camera module calibration method of this embodiment reduces the hardware requirements for calibrating the camera module 130, simplifies the calibration operation process, and helps to reduce manufacturing costs and improve production efficiency.

[0133] As long as it does not violate the creative ideas of the present invention, any combination of the various embodiments of the present invention shall be regarded as the contents disclosed by the present invention; within the technical concept of the present invention, any combination of various simple modifications of the technical scheme and different embodiments that does not violate the creative ideas of the present invention shall be within the protection scope of the present invention.

Claims

1. A camera module calibration method, characterized in that: The following steps are involved: S1, obtaining a resolution change curve of a camera module to be calibrated; S2, adjusting the position and tilt of the image sensor assembly of the camera module relative to the lens according to the resolution change curve, so that the image sensor assembly reaches an optimal sensing position and alignment state relative to the lens; S3, obtaining the resolution change curve of the camera module to be calibrated again to determine whether the adjustment effect meets the calibration requirements; S4, if the adjustment effect meets the calibration requirements, the position data of the adjusted image sensor assembly and the lens are recorded and stored.

2. The camera module calibration method according to claim 1, characterized in that: The step S1 comprises: The image sensor assembly is controlled to move along the optical axis direction of the lens by the axial adjustment assembly of the camera module. During the movement, the image sensor assembly senses the image captured by the lens and generates a corresponding image signal; at the same time, the position change of the image sensor assembly relative to the lens is detected to generate a corresponding position signal; A resolution change curve is drawn according to the corresponding relationship between the resolution of the image signal and the position signal.

3. The camera module calibration method according to claim 2, characterized in that: The step of drawing a resolution change curve according to the corresponding relationship between the resolution of the image signal and the position signal comprises: The central area of ​​the field of view of the lens is defined as the zero field of view, the edge area outside the zero field of view is defined as the outer field of view, and the outer field of view detection point is selected in the outer field of view; An image signal generated by the image sensor component sensing an image captured through the zero field of view is defined as a zero field of view image signal, and an image signal generated by the image sensor component sensing an image captured through the external field of view detection point is defined as an external field of view image signal; A zero-field-of-view resolution change curve is drawn according to the corresponding relationship between the resolution of the zero-field-of-view image signal and the position signal, and an external-field-of-view resolution change curve is drawn according to the corresponding relationship between the resolution of the image signal of the external-field-of-view detection point and the position signal.

4. The camera module calibration method according to claim 3, characterized in that: The step S2 comprises: Determine the optimal sensing position of the image sensor assembly relative to the lens according to the zero field of view resolution change curve, and move the image sensor assembly to the optimal sensing position; Determine the inclination of the edge area of ​​the image sensor assembly relative to the central area through the external field resolution change curve; The edge area of ​​the image sensor assembly is controlled to move by the axial adjustment assembly to adjust the tilt of the edge area of ​​the image sensor assembly so that the image sensor assembly is parallel to the imaging plane of the lens.

5. The camera module calibration method according to claim 4, characterized in that: The step S3 comprises: Again, a zero-field-of-view resolution change curve is plotted according to the corresponding relationship between the resolution of the zero-field-of-view image signal and the position signal, and an external-field-of-view resolution change curve is plotted according to the corresponding relationship between the resolution of the image signal of the external-field-of-view detection point and the position signal; The abscissa of the highest point of the zero field resolution change curve obtained again is compared with the abscissa of the highest point of the outside field resolution change curve, and whether the adjustment effect meets the calibration requirements is determined based on the comparison result.

6. The camera module calibration method according to claim 5, characterized in that: The step S4 comprises: The position data of the image sensor assembly and the lens, as well as the relative position data of each area of ​​the image sensor assembly and the lens are recorded and stored.

7. The camera module calibration method according to claim 6, characterized in that: The following steps are also included: S5, reassembling the lens according to the adjusted position data of the image sensor assembly and the lens.

8. The camera module calibration method according to claim 7, characterized in that: The step S5 comprises: Fix the image sensor assembly according to the position data recorded in step S4; Remove the lens from the housing of the camera module and apply glue to the housing; Reinstalling the lens into the housing for bonding, so that the position of the lens after bonding is consistent with the position data recorded in step S4; The glue is cured to secure the lens in the housing.

9. The camera module calibration method according to claim 1, characterized in that: The following steps are also included: If it is determined in step S3 that the adjustment effect does not meet the calibration requirements, then return to step S2, and repeat step S2 and step S3 until the adjustment effect meets the calibration requirements.

10. The camera module calibration method according to any one of claims 1 to 9, characterized in that: The following steps are also included: S0, perform preliminary assembly, signal connection and preliminary calibration on the camera module to be calibrated, so that the camera module is connected to the control unit, and the geometric center of the imaging area of ​​the image sensor component of the camera module is aligned with the optical axis of the lens of the camera module.

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