Camera module and image quality compensation method thereof

Abstract

The invention discloses a camera module and an image quality compensation method thereof, and the method comprises the steps: controlling a compensation lens drive assembly of a to-be-calibrated module to drive a compensation lens group to move to achieve the focusing operation when the to-be-calibrated module is located in a scene where a checkerboard image is obtained at a target object distance, and determining an analysis force curve of the to-be-calibrated module; determining inclination characteristics of the compensation lens group after focusing operation according to the analytic force curve; determining compensation characteristics of a photosensitive chip of the to-be-calibrated module according to the inclination characteristics, and controlling a chip driving assembly of the to-be-calibrated module to drive the photosensitive chip to adjust according to the compensation characteristics; and updating an analytic force curve based on the adjusted photosensitive chip, and when the updated analytic force curve meets the analytic force requirement, constructing an association relationship among the target object distance, the focusing position of the compensation lens group and the compensation feature. According to the invention, the inclination degree of the photosensitive chip is adjusted to compensate the image plane inclination caused by the movement of the compensation lens group in the internal focusing process, and the imaging quality is improved.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a camera module and an image quality compensation method thereof. Background Art

[0002] Internal focusing can significantly reduce the thickness of the lens and improve the resolution of the lens at close focus. However, in optical systems with strict tolerance requirements such as mobile phone lenses, internal focusing has the following technical defects:

[0003] When the driving member (such as a motor) drives the compensating lens group to move, the motor will tilt, which will cause the compensating lens group to tilt, thereby causing the image quality on the photosensitive chip to deteriorate.

[0004] Therefore, how to improve the imaging quality of the lens' internal focusing is a problem that needs to be solved urgently. Summary of the invention

[0005] The embodiment of the present application provides a camera module and an image quality compensation method thereof, thereby solving the technical problem in the prior art that a driving component drives a compensation lens group, causing the compensation lens group to tilt, thereby reducing the imaging quality on a photosensitive chip, and achieving the technical effect of improving the imaging quality of the lens focusing.

[0006] In a first aspect, the present application provides a camera module image quality compensation method, the method comprising:

[0007] When the module to be calibrated is in a scene where a chessboard image is acquired at a target object distance, the compensation lens driving component of the module to be calibrated is controlled to drive the compensation lens group to move to achieve a focusing operation, and the resolution curve of the module to be calibrated is determined;

[0008] Determine the tilt characteristics of the compensation lens group after the focusing operation according to the resolution curve;

[0009] Determine the compensation characteristics of the photosensitive chip of the module to be calibrated according to the tilt characteristics, and control the chip driving component of the module to be calibrated to drive the photosensitive chip to adjust according to the compensation characteristics;

[0010] The resolution curve is updated based on the adjusted photosensitive chip. When the updated resolution curve meets the resolution requirement, a correlation relationship is constructed among the target object distance, the focus position of the compensation lens group and the compensation feature. The correlation relationship is used to perform image quality compensation during the shooting process when the module to be calibrated is at the target object distance.

[0011] Furthermore, after establishing the correlation relationship among the target object distance, the focus position of the compensation lens group and the compensation feature, the method further includes:

[0012] Determine the correlation relationships corresponding to a plurality of different target object distances;

[0013] The correlation relationships corresponding to multiple different target object distances are fitted to construct a continuous relationship between the focus position and compensation characteristics of the module to be calibrated at different continuous object distances. The continuous relationship is used to perform image quality compensation during the shooting process when the module to be calibrated is at different object distances.

[0014] Furthermore, after constructing the continuous relationship between the focus position and the compensation feature of the module to be calibrated at different object distances, the method further includes:

[0015] When shooting with the module to be calibrated, the continuous relationship is queried according to the focus position of the compensation lens group in the module to be calibrated to determine the actual compensation characteristics corresponding to the photosensitive chip in the current state;

[0016] The photosensitive chip is controlled to adjust according to the actual compensation characteristics to compensate for the image quality of the module to be calibrated.

[0017] Furthermore, the target object distance is greater than or equal to 3 centimeters.

[0018] Further, the compensation feature of the photosensitive chip of the module to be calibrated is determined according to the tilt feature, and the chip driving component of the module to be calibrated is controlled to drive the photosensitive chip to adjust according to the compensation feature, including:

[0019] Determine the height variation characteristics of the photosensitive chip in at least three directions according to the tilt characteristics; the compensation characteristics include the height variation characteristics in at least three directions;

[0020] The control chip driving component changes the height of the photosensitive chip in the corresponding direction according to the height change characteristics in at least three directions, so that the photosensitive chip is adjusted according to the compensation characteristics.

[0021] Further, controlling the compensation lens driving component of the module to be calibrated to drive the compensation lens group to move to achieve a focusing operation includes:

[0022] Move the compensation lens group at least twice according to the initial step length of the module to be calibrated, and determine a first change characteristic group of the resolution of the module to be calibrated before and after the two most recent movements of the compensation lens group;

[0023] When the first change characteristic group indicates that the resolution is increasing, a moving step length is determined according to the first change characteristic group, the compensation lens group is moved according to the moving step length, and a second change characteristic group of the resolution of the module to be calibrated before and after the last two movements of the compensation lens group is determined;

[0024] determining whether the second change characteristic group indicates that the resolving power is increasing;

[0025] When the second change characteristic group indicates that the resolution is increasing, the moving step length is updated according to the second change characteristic group, and the compensation lens group is moved according to the updated moving step length;

[0026] The second change feature group is updated based on the resolution before and after the two most recent movements of the compensation lens group, and the step of determining whether the second change feature group indicates that the resolution is increasing is returned to execute until the updated second change feature group indicates that the resolution is unchanged or decreases for the first time, and the focus position of the compensation lens group when the resolution is unchanged or decreases for the first time is recorded.

[0027] Further, the first change feature group and the second change feature group both include a resolution force momentum feature and a resolution force acceleration feature;

[0028] The resolution momentum characteristic refers to the ratio between the difference in resolution before and after the nth movement of the compensation lens group and the resolution after the n-1th movement; n is a positive integer greater than 2;

[0029] The resolution acceleration characteristic refers to the difference between the first ratio and the second ratio. The first ratio refers to the ratio between the difference in resolution corresponding to before and after the nth movement of the compensation lens group and the resolution corresponding to after the nth movement. The second ratio refers to the ratio between the difference in resolution corresponding to before and after the n-2th movement of the compensation lens group and the resolution corresponding to after the n-1th movement.

[0030] Further, updating the moving step length according to the second change feature group includes:

[0031] The moving step length corresponding to the current movement of the compensation lens group is updated according to the initial step length and the resolving force momentum characteristics and the resolving force acceleration characteristics corresponding to the most recent movement.

[0032] Further, determining the tilt characteristics of the compensation lens group after the focusing operation according to the resolution curve includes:

[0033] Determine the central field curvature of the central field of view of the module to be calibrated and the peripheral field curvatures of multiple peripheral fields of view according to the resolution curve;

[0034] The tilt degree of the compensation lens group in each peripheral field after the focusing operation is determined according to the difference between each peripheral field curvature and the central field curvature. The tilt characteristic includes the tilt degree of the compensation lens group in each peripheral field.

[0035] In a second aspect, the present application provides a camera module, the camera module comprising:

[0036] A lens assembly, comprising a compensating lens group and a fixed lens group;

[0037] A compensating lens driving component, used for driving the compensating lens group to move to achieve focusing operation;

[0038] Photosensitive chip;

[0039] The chip driving component is used to drive the photosensitive chip to adjust according to the compensation characteristics, so that the adjusted photosensitive chip compensates for the tilt characteristics of the compensation lens group after the focusing operation.

[0040] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0041] This embodiment uses the module to be calibrated to obtain a checkerboard image at the target object distance, controls the compensation lens driving component to drive the compensation lens group to move to achieve a focusing operation, and determines the resolution curve of the module to be calibrated, obtains the tilt feature caused by the focusing operation based on the resolution curve, determines the compensation feature of the photosensitive chip based on the tilt feature, and then adjusts the tilt degree of the photosensitive chip according to the compensation feature, binds the target object distance, the focus position of the compensation lens group and the compensation feature of the photosensitive chip to obtain an associated relationship, so that the module to be calibrated can call the associated relationship during the actual shooting process to improve the problem of decreased resolution during the focusing process of the internal focus lens, adjust the tilt degree of the photosensitive chip to compensate for the image plane tilt caused by the movement of the compensation lens group during the internal focusing process, and improve the imaging clarity and imaging quality. It can be seen that the solution provided in this embodiment can calibrate the assembled module to be calibrated, which mainly relies on the checkerboard image and the resolution curve of the module to be calibrated during the process of shooting the checkerboard image, to obtain the correlation between the target object distance, the focusing position of the compensation lens group and the compensation characteristics of the photosensitive chip, and store this correlation in the module to be calibrated, so that the module to be calibrated can compensate for the image plane tilt caused by the movement of the compensation lens group during the internal focusing process by adjusting the inclination of the photosensitive chip during the shooting process, thereby improving the imaging clarity and the imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 (a) is a schematic diagram showing an initial state in which the compensation lens group does not perform a focusing operation;

[0044] Figure 1 (b) is a schematic diagram showing a state after the compensation lens group moves to perform a focusing operation;

[0045] Figure 2 A schematic diagram showing a state where a photosensitive chip is tilted;

[0046] Figure 3 A cross-sectional view of the camera module provided in this embodiment;

[0047] Figure 4 An axial cross-sectional view of the camera module provided in this embodiment;

[0048] Figure 5 A schematic diagram of the exploded structure of the camera module provided in this embodiment;

[0049] Figure 6 A schematic diagram of the structure of the FPC provided in this embodiment;

[0050] Figure 7 A schematic diagram of a flow chart of a camera module image quality compensation method provided in this embodiment;

[0051] Figure 8 A schematic diagram of a calibration scenario provided in this embodiment;

[0052] Fig. 9 A schematic diagram showing the relationship between the central field of view and the peripheral field of view provided in this embodiment;

[0053] Fig.10 for Fig. 9 Schematic diagram of the resolution curves corresponding to the central field of view and the four peripheral fields of view respectively;

[0054] Fig.11 Schematic diagram of adjusting the height variation characteristics corresponding to the four sides of the photosensitive chip in this embodiment;

[0055] Fig.12 It is a schematic diagram of a curve of continuous relationships corresponding to continuously different object distances obtained by fitting multiple correlation relationships corresponding to the four edges of the photosensitive chip.

[0056] Reference numerals:

[0057] 1-fixed lens group, 2-compensation lens group, 3-AF coil, 4-AF magnet, 5-chip displacement magnet, 6-filter bracket, 7-photosensitive chip, 8-motor housing, 9-carrier, 10-AF group bracket, 11-chip displacement coil, 12-filter, 13-FPC, 131-active side, 132-driving circuit, 133-control interface, 21-chessboard, 22-module to be calibrated, 23-driving module, 24-computer system. DETAILED DESCRIPTION

[0058] The embodiment of the present application provides a camera module and an image quality compensation method thereof, thereby solving the technical problem in the prior art that a driving component drives a compensation lens group, causing the compensation lens group to tilt, thereby reducing the imaging quality on a photosensitive chip.

[0059] The technical solution of the embodiment of the present application is to solve the above technical problems, and the overall idea is as follows:

[0060] A camera module image quality compensation method, the method comprising: when a module 22 to be calibrated is in a scene where an image of a chessboard 21 is acquired at a target object distance, controlling a compensation lens driving component of the module 22 to be calibrated to drive a compensation lens group 2 to move to achieve a focusing operation, and determining a resolution curve of the module 22 to be calibrated; determining a tilt feature of the compensation lens group 2 after the focusing operation according to the resolution curve; determining a compensation feature of a photosensitive chip 7 of the module 22 to be calibrated according to the tilt feature, and controlling a chip driving component of the module 22 to drive the photosensitive chip 7 to adjust according to the compensation feature; updating the resolution curve based on the adjusted photosensitive chip 7, and when the updated resolution curve meets the resolution requirement, constructing an association relationship among the target object distance, the focus position of the compensation lens group 2, and the compensation feature, the association relationship being used for image quality compensation during shooting when the module 22 to be calibrated is at the target object distance.

[0061] The present embodiment utilizes the module to be calibrated 22 to acquire the image of the chessboard 21 at the target object distance, controls the compensation lens driving component to drive the compensation lens group 2 to move to realize the focusing operation, and determines the resolution curve of the module to be calibrated 22, obtains the tilt feature caused by the focusing operation based on the resolution curve, determines the compensation feature of the photosensitive chip 7 based on the tilt feature, and then adjusts the tilt degree of the photosensitive chip 7 according to the compensation feature, binds the target object distance, the focus position of the compensation lens group 2 and the compensation feature of the photosensitive chip 7 to obtain an associated relationship, so that the module to be calibrated 22 can call the associated relationship during the actual shooting process to improve the problem of decreased resolution during the focusing process of the internal focus lens, adjusts the tilt degree of the photosensitive chip 7 to compensate for the image plane tilt caused by the movement of the compensation lens group 2 during the internal focusing process, and improves the imaging clarity and the imaging quality.

[0062] It can be seen that the solution provided in this embodiment can calibrate the assembled module 22 to be calibrated, which mainly relies on the checkerboard image 21 and the resolution curve of the module 22 to be calibrated during the process of shooting the checkerboard image 21, to obtain the correlation between the target object distance, the focusing position of the compensation lens group 2 and the compensation characteristics of the photosensitive chip 7, and store this correlation in the module 22 to be calibrated, so that the module 22 to be calibrated can compensate for the image plane tilt caused by the movement of the compensation lens group 2 during the internal focusing process by adjusting the inclination of the photosensitive chip 7 during the shooting process, thereby improving the imaging clarity and the imaging quality.

[0063] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0064] First of all, the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0065] Internal focusing can significantly reduce the thickness of the lens and improve the resolution of the lens at close focus. However, in optical systems with strict tolerance requirements such as mobile phone lenses, internal focusing has the following technical defects:

[0066] When the driving member (such as a motor) drives the compensation lens group 2 to move, the motor will tilt, which will cause the compensation lens group 2 to tilt, and finally reduce the imaging quality on the photosensitive chip 7.

[0067] like Figure 1 As shown, Figure 1 Included Figure 1 (a) and Figure 1 (b) Figure 1 (a) represents the initial state where the compensation lens group 2 is not in focus operation, Figure 1 (b) shows the state after the compensation lens group 2 moves to perform the focusing operation. Figure 1 It can be seen from (a) that when the compensation lens group 2 does not move, the optical axes of the fixed lens group 1 and the compensation lens group 2 coincide with each other. Figure 1 The vertical line in (a). Figure 1 It can be seen from (b) that after the compensation lens group 2 moves, the optical axis of the compensation lens group 2 tilts, and the optical axis of the compensation lens group 2 is Figure 1 The dotted line in (b) shows that the optical axis of the fixed lens group 1 is Figure 1 The vertical straight line in (b) causes the optical axes of the fixed lens group 1 and the compensation lens group 2 to not coincide. In this case, the image on the photosensitive chip 7 is unclear and uneven, resulting in relatively poor image quality.

[0068] In order to improve the image quality of the lens focusing, this embodiment provides a camera module and its image quality compensation method, which mainly compensates for the tilt of the compensation lens group 2 by changing the tilt degree of the imaging chip, thereby improving the image quality of the lens focusing, that is, giving the image on the photosensitive chip 7 a tilt compensation amount, so that the imaging system returns to a clear state. Figure 2 As shown, Figure 2 The dotted line in the upper and lower directions indicates the optical axis of the compensation lens group 2. Figure 2 The dotted lines in the left and right directions represent the tilted photosensitive chip 7. By adjusting the tilt of the photosensitive chip 7, the optical axis of the compensation lens group 2 is placed in the central field of view of the photosensitive chip 7 to improve the imaging quality.

[0069] First, the camera module provided in this embodiment is described.

[0070] A camera module provided in this embodiment can be referred to Figure 3-Figure 5 , mainly including:

[0071] A lens assembly, comprising a compensating lens group 2 and a fixed lens group 1;

[0072] A compensation lens driving component, used for driving the compensation lens group 2 to move to achieve a focusing operation;

[0073] Photosensitive chip 7;

[0074] The chip driving component is used to drive the photosensitive chip 7 to adjust according to the compensation characteristics, so that the adjusted photosensitive chip 7 compensates for the tilt characteristics of the compensation lens group 2 after the focusing operation.

[0075] like Figure 3 , Figure 4 and Figure 5 As shown, Figure 3 A cross-sectional view of the camera module provided in this embodiment, Figure 4 This is an axial cross-sectional view of the camera module provided in this embodiment, Figure 5 A schematic diagram of the exploded structure of the camera module provided in this embodiment.

[0076] like Figure 3 , Figure 4 and Figure 5 As shown, the lens assembly includes a compensating lens group 2 and a fixed lens group 1, the compensating lens group 2 and the fixed lens group 1 are arranged in contact and stacked, the fixed lens group 1 is located on the side close to the object being photographed, and the compensating lens group 2 is located on the side close to the photosensitive chip 7. Figure 3-Figure 5 As shown, the compensating lens group 2 is located at the lower side of the fixed lens group 1 .

[0077] like Figure 3 , Figure 4 and Figure 5 As shown, the compensating lens driving assembly includes a motor housing 8, a carrier 9, an AF (alternating and direct current) coil 3, an AF magnet 4 and an AF group bracket 10. The AF magnet 4 and the AF coil 3 (equivalent to a motor) are used to drive the compensating lens group 2 to move up and down to achieve a focusing operation. The motor housing 8 covers the outside of the lens assembly, and the light-incoming side of the fixed lens group 1 passes through the hole at the top of the motor housing 8 to be exposed to the outside, so as to obtain external light. The carrier 9 is arranged on the lower side of the compensating lens group 2, and the carrier 9 is used to carry the AF coil 3 and the AF magnet 4. The AF group bracket 10 is arranged on the lower side of the carrier 9.

[0078] like Figure 3 , Figure 4 and Figure 5 As shown, the chip driving assembly includes a chip displacement magnet 5, a chip displacement coil 11 and a spring plate (also called FPC13), and the chip displacement magnet 5 is arranged on the lower side or inside the AF group bracket 10. The camera module also includes a filter 12 and a filter bracket 6. The filter bracket 6 is arranged on the lower side of the AF group bracket 10, the chip displacement coil 11 is arranged inside or on the lower side of the filter bracket 6, and the filter 12 is arranged at the hole in the middle of the filter bracket 6. The photosensitive chip 7 is arranged on the FPC13, and the photosensitive chip 7 is on the lower side of the filter 12, so that the light transmitted by the lens assembly can pass through the filter 12 and then be projected on the photosensitive chip 7. FPC13 is as shown Figure 6 As shown, the photosensitive chip 7 is arranged on the upper surface of the active side 131 of the FPC 13, and the chip displacement magnet 5 and the chip displacement coil 11 cooperate with each other, that is, when the photosensitive chip 7 needs to move, current is input to the chip displacement coil 11 to generate magnetic force, which pushes the photosensitive chip 7 to move up and down, so that the plane where the active side 131 of the FPC 13 is located is tilted, thereby achieving the purpose of adjusting the tilt degree of the photosensitive chip 7, so that the optical axis of the compensation lens group 2 can be placed in the central field of view of the photosensitive chip 7 to improve the imaging quality. The specific adjustment process of the photosensitive chip 7 will be described when describing the camera module image quality compensation method, and will not be described here.

[0079] like Figure 6 As shown, the active side 131 of the FPC 13 includes four edges, each of which corresponds to a driving circuit 132. The four driving circuits 132 can be controlled individually, and different thrusts can be generated by inputting currents of different magnitudes. By inputting the same or different currents to the driving circuits 132 on the four sides, the height of each side of the active side 131 of the FPC 13 can be changed, and the plane where the photosensitive chip 7 is located can be controlled to change the degree of inclination.

[0080] It should be noted that the shape of the active side 131 of the FPC 13 can be set according to actual conditions, and the number of the corresponding driving circuits 132 can also be adjusted according to the different shapes, as long as the plane where the active side 131 is located can be tilted according to the tilt of the compensation lens group 2. For example, Figure 6 The active side 131 is a square with four sides. A driving circuit 132 may be provided for each of the four sides, or only one driving circuit 132 may be provided for any three sides. The driving circuit 132 may be provided in the middle of the side of the active side 131, or at the end of the active side 131.

[0081] That is to say, the chip driving component is used to drive the photosensitive chip 7 to adjust its height in at least three directions according to the compensation characteristics, so that the adjusted photosensitive chip 7 can compensate for the tilt characteristics of the compensation lens group 2 after the focusing operation.

[0082] The camera module provided in this embodiment adopts the in-lens focusing method, which can reduce the size of the camera module and realize the miniaturization of the camera module. More importantly, the problem of decreased resolution during the focusing process of the internal focusing lens can be improved by changing the inclination degree of the photosensitive chip 7, thereby significantly improving the imaging quality.

[0083] Secondly, the camera module image quality compensation method provided in this embodiment is described.

[0084] This embodiment provides Figure 7 A camera module image quality compensation method is shown, and the method includes steps S71 to S74.

[0085] Step S71, when the module to be calibrated 22 is in a scene where an image of the chessboard 21 is acquired at a target object distance, the compensation lens driving assembly of the module to be calibrated 22 is controlled to drive the compensation lens group 2 to move to achieve a focusing operation, and the resolution curve of the module to be calibrated 22 is determined;

[0086] Step S72, determining the tilt characteristics of the compensation lens group 2 after the focusing operation according to the resolution curve;

[0087] Step S73, determining the compensation characteristics of the photosensitive chip 7 of the module to be calibrated 22 according to the tilt characteristics, and controlling the chip driving component of the module to be calibrated 22 to drive the photosensitive chip 7 to adjust according to the compensation characteristics;

[0088] Step S74, updating the resolution curve based on the adjusted photosensitive chip 7. When the updated resolution curve meets the resolution requirement, constructing a correlation relationship among the target object distance, the focusing position of the compensation lens group 2 and the compensation characteristics. The correlation relationship is used to perform image quality compensation during the shooting process when the module to be calibrated 22 is at the target object distance.

[0089] Regarding step S71, when the module to be calibrated 22 is in a scene of acquiring an image of the chessboard 21 at a target object distance, the compensation lens driving component of the module to be calibrated 22 is controlled to drive the compensation lens group 2 to move to achieve a focusing operation, and determine the resolution curve of the module to be calibrated 22.

[0090] The module to be calibrated 22 is a module for focusing within the lens. Figure 3-Figure 5 The camera module shown is the module to be calibrated 22 for subsequent description.

[0091] First build a calibration scene, such as Figure 8As shown, it includes a chessboard 21 (also called a chart) for testing, a module to be calibrated 22, a driving module 23 and a computer system 24. The chessboard 21 is the object to be photographed, and the distance between the chessboard 21 and the module to be calibrated 22 is called the object distance, which is usually greater than or equal to 3 cm. The module to be calibrated 22 is connected to the driving module 23, and the driving module 23 is used to control the action of the compensation lens driving component and the chip driving component in the module to be calibrated 22. The computer system 24 is used to record the object distance between the chessboard 21 and the module to be calibrated 22, the focus position of the compensation lens group 2 in the module to be calibrated 22, the compensation characteristics of the tilt of the photosensitive chip 7, etc.

[0092] The object distance between the chessboard 21 to be measured and the module to be calibrated 22 is determined and recorded as the target object distance. The target object distance is a distance greater than or equal to 3 cm.

[0093] The module to be calibrated 22 acquires the image of the chessboard 21 at the target object distance, and controls the compensation lens driving component to drive the compensation lens group 2 to move the compensation lens to change the focal length and realize the focusing operation.

[0094] There are two specific ways of focusing operation. The first way is to gradually move the compensation lens group 2 according to the initial step length until a relatively optimal focusing position is reached. The second way includes steps S7111 to S7115.

[0095] Step S7111, moving the compensation lens group 2 at least twice according to the initial step length of the module to be calibrated 22, and determining a first change characteristic group of the resolution of the module to be calibrated 22 before and after the two most recent movements of the compensation lens group 2;

[0096] Step S7112, when the first change characteristic group indicates that the resolution is increasing, determine the moving step length according to the first change characteristic group, move the compensation lens group 2 according to the moving step length, and determine the second change characteristic group of the resolution of the module 22 to be calibrated before and after the last two movements of the compensation lens group 2;

[0097] Step S7113, determining whether the second change characteristic group indicates that the resolution is increasing;

[0098] Step S7114, when the second change characteristic group indicates that the resolution is increasing, updating the moving step length according to the second change characteristic group, and moving the compensation lens group 2 according to the updated moving step length;

[0099] Step S7115, based on the resolution before and after the two most recent movements of the compensation lens group 2, update the second change feature group, and return to the step of determining whether the second change feature group represents an increase in resolution, until the updated second change feature group represents that the resolution remains unchanged or decreases for the first time, and record the focus position of the compensation lens group 2 when the resolution remains unchanged or decreases for the first time.

[0100] Regarding step S7111, the compensation lens group 2 in the module to be calibrated 22 moves in units of step length. The initial step length is related to the system characteristics of the module to be calibrated 22, and the corresponding initial step length can be determined according to the system characteristics of the module to be calibrated 22, for example, 1 mm.

[0101] The compensation lens group 2 is moved at least twice according to the initial step length, and the resolution before and after each movement is recorded. The resolution can be represented by an MTF value or an SFR value, which can be selected according to actual conditions. The first change feature group is determined according to the resolution before and after the two most recent movements of the compensation lens group 2.

[0102] The first change feature group includes a resolution force momentum feature and a resolution force acceleration feature.

[0103] The resolution momentum characteristic refers to the ratio between the difference in resolution before and after the nth movement of the compensation lens group 2 and the resolution after the n-1th movement, and specifically, refer to Formula 1. n is a positive integer greater than 2.

[0104]

[0105] Where m is the analytical force-momentum characteristic, f n is the resolution corresponding to the nth movement; f n-1 It is the resolution after the n-1th movement and also the resolution before the nth movement. That is to say, the resolution after the n-1th movement is the same as the resolution before the nth movement.

[0106] The resolution acceleration characteristic refers to the difference between the first ratio and the second ratio. The first ratio refers to the ratio between the difference in resolution corresponding to before and after the nth movement of the compensation lens group 2 and the resolution corresponding to after the nth movement. The second ratio refers to the ratio between the difference in resolution corresponding to before and after the n-2th movement of the compensation lens group 2 and the resolution corresponding to after the n-1th movement. For details, please refer to Formula 2.

[0107]

[0108] Where a is the analytical acceleration characteristic, f n is the resolution corresponding to the nth movement; f n-1 is the resolution after the n-1th movement, and also the resolution before the nth movement. That is to say, the resolution after the n-1th movement is the same as the resolution before the nth movement. n-2It is the resolution after the n-2th movement and also the resolution before the n-1th movement. That is to say, the resolution after the n-2th movement is the same as the resolution before the n-1th movement.

[0109] For example, when the compensation lens group 2 is moved twice according to the initial step length, the first change characteristic group includes m1, m2 and a2, but m1 is not used in actual operation, so the first change characteristic group may also include only m2 and a2. It is determined whether the first change characteristic group indicates that the resolution is increasing.

[0110] When the first change characteristic group indicates that the resolution remains unchanged or is decreasing, it is considered that the module 22 to be calibrated is in a relatively optimal focusing position, and a correlation relationship between the target object distance and the focusing position of the compensation lens group 2 can be established, indicating that at the target object distance, the influence of the inclination of the compensation lens group 2 on the imaging quality can be ignored, and thus there is no need to adjust the inclination of the photosensitive chip 7.

[0111] When the first change feature group indicates that the resolution is increasing, it means that the module 22 to be calibrated is not yet in the relatively optimal focus position, and step S7112 needs to be continued.

[0112] Regarding step S7112, the moving step length of the current refocusing movement of the compensation lens group 2 is determined according to the first change feature group. Specifically, the moving step length corresponding to the current movement of the compensation lens group 2 is updated according to the initial step length and the resolution momentum characteristics and resolution acceleration characteristics corresponding to the most recent movement. For details, please refer to Formula 3.

[0113] s n =s b +αm n-1 +βa n-1 Formula 3

[0114] Among them, s n To compensate for the moving step length corresponding to the nth focusing movement of lens group 2, s b is the initial step size, α and β are coefficients, m n-1 is the analytical force momentum characteristic corresponding to the n-1th movement, a n-1 is the analytical acceleration characteristic corresponding to the n-1th movement.

[0115] For example, in step S7111, when the compensation lens group 2 is moved twice according to the initial step length, the first change characteristic group includes m2 and a2. If the first change characteristic group indicates that the resolution is increasing, then the movement step length s corresponding to the third movement of the compensation lens group 2 can be determined based on m2 and a2 in combination with Formula 3. 3 =s b +αm 2 +βa2 .

[0116] The compensation lens driving assembly is controlled to drive the compensation lens group 2 to move according to the moving step length, and a second change characteristic group of the resolution of the module to be calibrated 22 before and after the two most recent movements is determined. The second change characteristic group also includes a resolution momentum characteristic and a resolution acceleration characteristic. For details, please refer to the relevant description of the first change characteristic group, which will not be described in detail in this embodiment.

[0117] Regarding step S7113, it is determined whether the second change feature group indicates that the resolution is increasing. When the second change feature group indicates that the resolution is unchanged or decreasing, it is considered that the module 22 to be calibrated is already in the relative best focus position, and step S73 can be continued. When the second change feature group indicates that the resolution is increasing, it means that the module 22 to be calibrated is not yet in the relative best focus position, and step S7114 needs to be continued.

[0118] Regarding step S7114, when the second change feature group indicates that the resolution is increasing, a new moving step length is recalculated according to the second change feature group. The principle is similar to the principle of determining the moving step length according to the first change feature group in step S7112. For details, please refer to the relevant description of step S7112. This embodiment will not be repeated here. After the moving step length is updated, the compensation lens group 2 is moved according to the updated moving step length, and step S7115 is continued.

[0119] Regarding step S7115, after the compensation lens group 2 is moved according to the updated moving step length, the second change feature group is recalculated to update the second change feature group, and the process returns to step S7113 to determine whether the updated second change feature group indicates that the resolution is increasing. When the updated second change feature group indicates that the resolution is increasing, step S7114 and step S7115 are continued to be executed, and the process is repeated until the updated second change feature group indicates that the resolution remains unchanged or decreases for the first time. When the updated second change feature group indicates that the resolution remains unchanged or decreases for the first time, step S72 is continued to be executed.

[0120] Regarding the focusing operation involved in the present embodiment, the focusing method of the first method is relatively simple, but its focusing efficiency is low, and the focusing operation needs to be implemented step by step according to the initial step. The focusing method of the second method is relatively complex, but its focusing efficiency is high. The moving step length corresponding to the next move is determined according to the change characteristic group of the compensation lens group 2 after the last two moves, and the movement is performed according to the new moving step length. In this way, the focusing step length can be adjusted according to the actual situation, the focusing time is shortened, and the focusing efficiency is improved. For example, when the initial step length is 1mm, if the focus needs to move 10mm to find the relative best focus position under the current target object distance, then the first method needs to move 10 times, and the first two times in the second method move 1mm respectively. After the moving step length is re-determined, if the step length is 3mm, then only two or three more moves are needed to find the relative best focus position. That is to say, the first method needs to move 10 times, and the second method only needs to move about 5 times. It can be seen that the focusing efficiency of the second method is much higher. In actual operation, a specific focusing operation can be selected from the first method and the second method according to the actual demand for focusing efficiency.

[0121] Regarding step S72, the tilt characteristics of the compensation lens group 2 after the focusing operation are determined according to the resolution curve.

[0122] According to the system characteristics of the module 22 to be calibrated and the parameters of the checkerboard 21, the central field of view and the peripheral field of view of the module 22 to be calibrated can be distinguished. Fig. 9 As shown in FIG. 1 , the central field of view f0 and four peripheral fields of view f1, f2, f3, and f4 are shown. Different fields of view correspond to different resolution curves, such as Fig.10 As shown, Fig. 9 The schematic diagram of the resolution curve corresponding to the central field of view and the four peripheral fields of view is shown, the horizontal axis is the distance of the image plane deviation, and the vertical axis represents the MTF value. The more the image plane deviates, the smaller the MTF value is, and the worse the imaging quality is. In this embodiment, the number and position of the peripheral fields of view can be determined according to actual conditions, and this embodiment does not limit this.

[0123] The central field curvature of the central field of view of the module 22 to be calibrated and the peripheral field curvatures of multiple peripheral fields of view are determined according to the resolution curve; the central field curvature and the peripheral field curvature can be obtained from the resolution curve.

[0124] The degree of inclination of the compensation lens group 2 in each peripheral field after the focusing operation is determined according to the difference between each peripheral field curvature and the central field curvature. The inclination characteristic includes the degree of inclination of the compensation lens group 2 in each peripheral field.

[0125] When the compensation lens group 2 is tilted, there will be differences in the imaging quality of the photosensitive chip 7 in different peripheral fields of view, and the imaging quality of the central field of view will be relatively good. Then, the central field curvature of the central field of view can be used as a benchmark to determine the difference between the peripheral field curvature and the central field curvature of each peripheral field of view. Based on these difference values, the degree of tilt of the compensation lens group 2 in each peripheral field of view can be determined, and the degree of tilt of each peripheral field of view can reflect the tilt characteristics of the compensation lens group 2 during the focusing process.

[0126] For example, suppose Fig. 9 The field curvature values ​​of the central field of view and the four peripheral fields of view are Z0, Z1, Z2, Z3, and Z4 respectively. Taking the field curvature Z0 of the central field of view as the reference point, the field curvature difference values ​​corresponding to the peripheral fields of view are Z1-Z0, Z2-Z0, Z3-Z0, and Z4-Z0 respectively. The plane where the photosensitive chip 7 is located is taken as the XOY plane (the X and Y directions can be the length and width of the photosensitive chip 7), and a three-dimensional coordinate system is established with the field curvature as the Z direction. The center of the photosensitive chip 7 is taken as point O, and the length and width of the photosensitive chip 7 are set to X1 and Y1 respectively. Then, the plane coordinate points after the compensation lens group 2 is tilted can be constructed in the three-dimensional coordinate system, which are:

[0127] (0,-Y1 / 2,Z1-Z0), (0,Y1 / 2,Z2-Z0), (-X1 / 2,0,Z3-Z0), (X1 / 2,0,Z4-Z0).

[0128] The plane where the compensation lens group 2 is located after tilting can be determined through these four points. These four points are also the tilt characteristics of the compensation lens group 2 after tilting.

[0129] Regarding step S73, the compensation characteristics of the photosensitive chip 7 of the module to be calibrated 22 are determined according to the tilt characteristics, and the chip driving component of the module to be calibrated 22 is controlled to drive the photosensitive chip 7 to adjust according to the compensation characteristics.

[0130] Ideally, the photosensitive chip 7 should be tilted as much as the compensation lens group 2 tilts during the focusing operation, that is, the compensation lens group 2 and the photosensitive chip 7 should be balanced. Therefore, the tilt characteristics of the compensation lens group 2 can be directly used as the compensation characteristics of the photosensitive chip 7, so that the photosensitive chip 7 can completely compensate for the tilt of the compensation lens group 2. The tilt characteristics of the compensation lens group 2 are converted into the compensation characteristics of the photosensitive chip 7, and the compensation characteristics are converted into the control current of the chip driving component, and then the chip driving component drives the photosensitive chip 7 to adjust according to the compensation characteristics.

[0131] Specifically, the height variation characteristics of the photosensitive chip 7 in at least three directions can be determined according to the tilt characteristics; the compensation characteristics include the height variation characteristics in at least three directions. The control chip driving component changes the height of the photosensitive chip 7 in the corresponding direction according to the height variation characteristics in at least three directions, so that the photosensitive chip 7 is adjusted according to the compensation characteristics.

[0132] For example, Figure 6 As shown, four driving circuits 132 are arranged on the active side 131 of the FPC 13. Then, different driving currents of the four driving circuits 132 can be determined according to the compensation characteristics, thereby changing the inclination degree of the plane where the photosensitive chip 7 is located.

[0133] The heights of the four sides of the photosensitive chip 7 are independently controlled (at least three sides need to be able to adjust their heights so that the four sides can have height differences). As shown above, assuming that the tilt characteristics of the compensation lens group 2 are (0, -Y1 / 2, Z1-Z0), (0, Y1 / 2, Z2-Z0), (-X1 / 2, 0, Z3-Z0), (X1 / 2, 0, Z4-Z0), then the compensation characteristics are (0, -Y1 / 2, Z1-Z0), (0, Y1 / 2, Z2-Z0), (-X1 / 2, 0, Z3-Z0), (X1 / 2, 0, Z4-Z0), which are converted into corresponding control currents I1, I2, I3, I4, and the corresponding sides of the photosensitive chip 7 can be controlled to change the corresponding heights H1, H2, H3, H4. Fig.11 As shown, the four sides of the photosensitive chip 7 may correspond to height variation characteristics H1, H2, H3, and H4 respectively. By adjusting the heights of the four sides of the photosensitive chip 7, the tilt of the compensation lens group 2 can be compensated.

[0134] Regarding step S74, the resolution curve is updated based on the adjusted photosensitive chip 7. When the updated resolution curve meets the resolution requirement, an association relationship is constructed among the target object distance, the focusing position of the compensation lens group 2 and the compensation characteristics. The association relationship is used to perform image quality compensation during the shooting process when the module to be calibrated 22 is at the target object distance.

[0135] Ideally, after the photosensitive chip 7 adjusts its tilt, the plane where the compensation lens group 2 is located should remain parallel to the plane where the photosensitive chip 7 is located. In actual operation, although the imaging quality is best when the plane where the compensation lens group 2 is located is balanced with the plane where the photosensitive chip 7 is located, the conditions for achieving this are relatively harsh, and it is difficult to determine whether the two are parallel. Therefore, this embodiment determines whether the tilt of the photosensitive chip 7 has achieved the purpose of tilt compensation for the compensation lens group 2 by determining whether the resolution has been improved.

[0136] Specifically, after the photosensitive chip 7 adjusts the tilt degree, it can be determined whether the resolution is improved by using a gradient algorithm, for example, the Tenengrad algorithm can be used, see formula 4.

[0137]

[0138] Among them, S 1 (x,y),S 2 (x,y),S 3 (x,y) and S 4 (x, y) are the first-order differences between a pixel in the checkerboard image 21 obtained in the module to be calibrated 22 and its eight adjacent pixels in the horizontal, vertical, left diagonal and right diagonal directions, respectively, which can be expressed as

[0139] Among them, g 1 , g 2 , g 3 , g 4 is a constant, f(x,y) is the grayscale value of the target pixel, and this grayscale value can be defined as a constant. 1 , g 2 , g 3 , g 4 It can be shown as follows.

[0140]

[0141] Based on the adjusted resolution curve of the photosensitive chip 7, a gradient algorithm is used to determine whether the updated resolution curve meets the resolution requirement. If it does, the target object distance, the focus position of the compensation lens group 2, and the compensation characteristics of the photosensitive chip 7 are bound, and an association relationship is established and stored. In actual use of the module 22 to be calibrated, when the object distance is the target object distance, the compensation characteristics corresponding to the photosensitive chip 7 can be determined according to the association relationship, and then the photosensitive chip 7 can be controlled to adjust the tilt degree to achieve the purpose of improving the image quality.

[0142] It should be noted that the compensation feature in the association relationship can be the compensation feature itself, or it can be a tilt feature, or it can be the current value of each driving circuit 132 in the chip driving component corresponding to the compensation feature. In actual operation, it can be selected according to the actual situation.

[0143] Further, after constructing the correlation relationship among the target object distance, the focus position of the compensation lens group 2 and the compensation characteristic, the method further includes step S81-step S82.

[0144] Step S81, determining the association relationships corresponding to a plurality of different target object distances;

[0145] Step S82, fitting the correlation relationships corresponding to multiple different target object distances, and constructing a continuous relationship between the focus position and compensation characteristics of the module to be calibrated 22 at different continuous object distances. The continuous relationship is used to perform image quality compensation during the shooting process when the module to be calibrated 22 is at different object distances.

[0146] Regarding step S81, multiple different target object distances are all distances greater than or equal to 3 cm, and the number can be more than 3. The more the number, the more accurate the continuous relationship finally obtained. The target object distance can be infinite, but in the actual calibration process, 5 meters (or other distances) can be used instead of the infinite distance. For example, within the range of 3 cm to 5 meters, 9 target object distances are selected, namely 10 cm, 50 cm, 1 meter, 1.5 meters, 2 meters, 2.5 meters, 3 meters, 4 meters, and 5 meters. For each target object distance, the association relationship corresponding to each target object distance is determined by the method of steps S71-step S74.

[0147] Regarding step S82, data fitting is performed on the correlation relationships corresponding to the multiple target object distances, thereby obtaining a continuous relationship between the focus position of the compensation lens group 2 and the compensation characteristics of the photosensitive chip 7 at continuously different object distances. Fig.12 As shown, it is a curve diagram of the continuous relationship corresponding to the continuous different object distances obtained after fitting the multiple correlation relationships corresponding to the four edges of the photosensitive chip, where the horizontal axis is the object distance and the vertical axis is the displacement height distance.

[0148] By fitting the correlation relationships corresponding to a plurality of different object distances, the continuous relationship corresponding to the continuous different object distances is determined, which can reduce the number of executions of step S71 to step S74, save calibration time, and improve calibration efficiency.

[0149] After constructing the continuous relationship between the focus position and the compensation feature of the module to be calibrated 22 at different object distances, the continuous relationship is recorded in the driving module 23 of the module to be calibrated 22, and then becomes a calibrated module, which can be directly put into use. That is, when shooting with the module to be calibrated 22 (here, the calibrated module), the continuous relationship is queried according to the focus position of the compensation lens group 2 in the module to be calibrated 22, and the actual compensation feature corresponding to the photosensitive chip 7 in the current state is determined; then the photosensitive chip 7 is controlled to adjust according to the actual compensation feature to compensate for the image quality of the module to be calibrated 22.

[0150] In addition, when shooting with the module to be calibrated 22 (here refers to the calibrated module) , the actual object distance between the module and the photographed object can also be obtained, and the actual focus position corresponding to the current state of the module and the actual compensation characteristics corresponding to the photosensitive chip 7 in the current state are determined based on the actual object distance query continuity relationship; then the compensation lens group 2 is controlled to reach the actual focus position to complete the focusing operation, and the photosensitive chip 7 is controlled to adjust according to the actual compensation characteristics to compensate for the image quality of the module to be calibrated 22.

[0151] In summary, the present embodiment utilizes the module to be calibrated 22 to acquire the image of the chessboard 21 at the target object distance, controls the compensation lens driving assembly to drive the compensation lens group 2 to move to realize the focusing operation, and determines the resolution curve of the module to be calibrated 22, obtains the tilt feature caused by the focusing operation based on the resolution curve, determines the compensation feature of the photosensitive chip 7 based on the tilt feature, and then adjusts the tilt degree of the photosensitive chip 7 according to the compensation feature, binds the target object distance, the focus position of the compensation lens group 2 and the compensation feature of the photosensitive chip 7 to obtain an associated relationship, so that the module to be calibrated 22 can call the associated relationship during the actual shooting process to improve the problem of decreased resolution during the focusing process of the internal focus lens, adjusts the tilt degree of the photosensitive chip 7 to compensate for the image plane tilt caused by the movement of the compensation lens group 2 during the internal focusing process, and improves the imaging clarity and the imaging quality.

[0152] It can be seen that the solution provided in this embodiment can calibrate the assembled module 22 to be calibrated, which mainly relies on the checkerboard image 21 and the resolution curve of the module 22 to be calibrated during the process of shooting the checkerboard image 21, to obtain the correlation between the target object distance, the focusing position of the compensation lens group 2 and the compensation characteristics of the photosensitive chip 7, and store this correlation in the module 22 to be calibrated, so that the module 22 to be calibrated can compensate for the image plane tilt caused by the movement of the compensation lens group 2 during the internal focusing process by adjusting the inclination of the photosensitive chip 7 during the shooting process, thereby improving the imaging clarity and the imaging quality.

[0153] Since the electronic device introduced in this embodiment is an electronic device used to implement the information processing method in the embodiment of the present application, based on the information processing method introduced in the embodiment of the present application, a person skilled in the art can understand the specific implementation of the electronic device of the present embodiment and its various variations, so how the electronic device implements the method in the embodiment of the present application is not described in detail here. As long as a person skilled in the art implements the electronic device used by the information processing method in the embodiment of the present application, it belongs to the scope of protection of this application.

[0154] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0155] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0156] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0157] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0158] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0159] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A camera module image quality compensation method, characterized in that: The method comprises: When the module to be calibrated is in a scene where a chessboard image is acquired at a target object distance, controlling the compensation lens driving component of the module to be calibrated to drive the compensation lens group to move to achieve a focusing operation, and determining a resolution curve of the module to be calibrated; Determining the tilt characteristics of the compensation lens group after the focusing operation according to the resolution curve; Determine the compensation feature of the photosensitive chip of the module to be calibrated according to the tilt feature, and control the chip driving component of the module to be calibrated to drive the photosensitive chip to adjust according to the compensation feature; The resolution curve is updated based on the adjusted photosensitive chip. When the updated resolution curve meets the resolution requirement, an association relationship is constructed among the target object distance, the focusing position of the compensation lens group and the compensation feature. The association relationship is used to perform image quality compensation during the shooting process when the module to be calibrated is at the target object distance.

2. The method according to claim 1, characterized in that After constructing the association relationship between the target object distance, the focus position of the compensation lens group and the compensation feature, the method further includes: Determine the association relationships corresponding to a plurality of different target object distances; The association relationships corresponding to the multiple different target object distances are respectively fitted to construct a continuous relationship between the focus position and the compensation feature of the module to be calibrated at different continuous object distances. The continuous relationship is used to perform image quality compensation during the shooting process when the module to be calibrated is at different object distances.

3. The method according to claim 2, characterized in that After constructing the continuous relationship between the focus position and the compensation feature of the module to be calibrated at different continuous object distances, the method further includes: When the module to be calibrated is used for shooting, the continuous relationship is queried according to the focus position of the compensation lens group in the module to be calibrated to determine the actual compensation feature corresponding to the photosensitive chip in the current state; The photosensitive chip is controlled to be adjusted according to the actual compensation characteristics to compensate for the image quality of the module to be calibrated.

4. The method according to claim 1 or 2, characterized in that: The target object distance is greater than or equal to 3 centimeters.

5. The method according to claim 1, characterized in that The step of determining the compensation feature of the photosensitive chip of the module to be calibrated according to the tilt feature, and controlling the chip driving component of the module to be calibrated to drive the photosensitive chip to adjust according to the compensation feature, comprises: Determine the height variation characteristics of the photosensitive chip in at least three directions according to the tilt characteristics; the compensation characteristics include the height variation characteristics in at least three directions; The chip driving component is controlled to change the height of the photosensitive chip in the corresponding direction according to the height variation characteristics in the at least three directions, so that the photosensitive chip is adjusted according to the compensation characteristics.

6. The method according to claim 1, characterized in that The controlling of the compensation lens driving component of the module to be calibrated to drive the compensation lens group to move to realize the focusing operation includes: Move the compensation lens group at least twice according to the initial step length of the module to be calibrated, and determine a first change characteristic group of the resolution of the module to be calibrated before and after the two most recent movements of the compensation lens group; When the first change feature group indicates that the resolution is increasing, determining a moving step length according to the first change feature group, moving the compensation lens group according to the moving step length, and determining a second change feature group of the resolution of the module to be calibrated before and after the two most recent movements of the compensation lens group; determining whether the second change characteristic group indicates that the resolving power is increasing; When the second change feature group indicates that the resolution is increasing, updating the moving step length according to the second change feature group, and moving the compensation lens group according to the updated moving step length; The second change feature group is updated based on the resolution before and after the two most recent movements of the compensation lens group, and the step of determining whether the second change feature group indicates that the resolution is increasing is returned to execute, until the updated second change feature group indicates that the resolution is unchanged or decreases for the first time, and the focus position of the compensation lens group when the resolution is unchanged or decreases for the first time is recorded.

7. The method according to claim 6, characterized in that The first change feature group and the second change feature group both include a resolution force momentum feature and a resolution force acceleration feature; The resolution momentum characteristic refers to the ratio between the difference in resolution before and after the nth movement of the compensation lens group and the resolution after the n-1th movement; n is a positive integer greater than 2; The resolution acceleration characteristic refers to the difference between a first ratio and a second ratio, wherein the first ratio refers to the ratio between the difference in resolution corresponding to before and after the nth movement of the compensation lens group and the resolution corresponding to after the nth movement, and the second ratio refers to the ratio between the difference in resolution corresponding to before and after the n-2th movement of the compensation lens group and the resolution corresponding to after the n-1th movement.

8. The method according to claim 7, characterized in that The updating of the moving step size according to the second change feature group comprises: The moving step length corresponding to the current movement of the compensation lens group is updated according to the initial step length and the resolution momentum characteristic and the resolution acceleration characteristic corresponding to the most recent movement.

9. The method according to claim 1, characterized in that The step of determining the tilt characteristics of the compensation lens group after the focusing operation according to the resolution curve includes: Determine the central field curvature of the central field of view of the module to be calibrated and the peripheral field curvatures of multiple peripheral fields of view according to the resolution curve; The degree of inclination of the compensation lens group in each peripheral field after the focusing operation is determined according to the difference between each peripheral field curvature and the central field curvature, and the inclination feature includes the degree of inclination of the compensation lens group in each peripheral field.

10. A camera module, characterized in that: The camera module comprises: A lens assembly, comprising a compensating lens group and a fixed lens group; A compensating lens driving assembly, used for driving the compensating lens group to move to achieve focusing operation; Photosensitive chip; The chip driving component is used to drive the photosensitive chip to adjust according to the compensation characteristics, so that the adjusted photosensitive chip compensates for the tilt characteristics of the compensation lens group after the focusing operation.

Images