Voice coil motor, camera module and electronic equipment

Abstract

The present application discloses a voice coil motor, a camera module and an electronic device, and relates to the field of camera technology. The voice coil motor includes: two positioning magnets respectively arranged on the lens; two TMR angle sensors respectively arranged on the camera module, and the two TMR angle sensors are used to detect the components of the magnetic field strength along the direction of lens movement and the direction of the positioning magnet toward the TMR angle sensor during the movement of the positioning magnet, and thereby determine the position of the positioning magnet; a driving component, which is used to adjust the position of the lens according to the position of the positioning magnet. The voice coil motor, camera module and electronic device provided by the present application can realize long-stroke feedback control of more than 4000um, meet the requirements of precise closed-loop control of lens movement, and thus ensure the accuracy of shooting.

Description

Technical Field

[0001] The present application relates to the field of camera technology, and in particular to a voice coil motor, a camera module and an electronic device. Background Art

[0002] With the continuous advancement of science and technology, smartphones have become an indispensable item in people's daily lives. Among them, the camera function, as an important part of the functions of smartphones, allows users to perform related shooting and video calls. However, the camera in the existing smartphones is mainly aimed at the scene of autofocus with a small depth of field. The rated stroke of the linear motion of the motor in the camera only needs to be within 600um, which is not enough to meet people's needs. In order to achieve the multi-distance shooting function of long-distance, medium-distance and close-range, the existing technology mainly adopts two methods: one is to use multiple modules for different shooting, but this will cause too many parts in the module, complex structure, resulting in the problem of excessive module volume, and image jump phenomenon will occur when focusing; the other solution is to use a camera module that can achieve continuous zoom, and drive the lens group through a motor to achieve long-stroke zoom. However, the long-stroke displacement requires the motor linear motion stroke to be generally above 3000um. The existing motor feedback magnetic circuit design does not meet the long-stroke displacement, so that the lens module cannot achieve accurate closed-loop control of the lens displacement. Summary of the invention

[0003] The present application provides a voice coil motor, a camera module and an electronic device to achieve precise closed-loop control of lens movement within a long travel range.

[0004] This application provides:

[0005] A voice coil motor, used to control the movement of a lens in a camera module, comprising:

[0006] Two positioning magnets are respectively arranged on the lens along the direction in which the lens moves, and opposite magnetic poles on the two positioning magnets are arranged opposite to each other along the direction in which the lens moves;

[0007] Two TMR angle sensors are respectively arranged on the camera module along the direction of movement of the lens, and the two TMR angle sensors are used to detect the components of the magnetic field strength along the direction of movement of the lens and the direction of the positioning magnet toward the TMR angle sensor during the movement of the positioning magnet, so as to determine the position of the positioning magnet; and

[0008] The driving assembly is used to adjust the position of the lens according to the position of the positioning magnet.

[0009] In some possible embodiments, the two TMR angle sensors determine the position calibration value detected jointly by the two TMR angle sensors based on the components of the magnetic field strength in two directions detected, and determine the position of the positioning magnet based on a curve of the position calibration value detected jointly by the two TMR angle sensors changing with the lens stroke.

[0010] In some possible implementations, a curve of the position calibration quantity detected jointly by the two TMR angle sensors changing with the lens stroke is determined based on a curve of the position calibration quantity detected individually by the two TMR angle sensors changing with the lens stroke and a formula arctan(TMR1, TMR2), wherein TMR1 and TMR2 respectively represent the position calibration quantities detected by the two TMR angle sensors.

[0011] In some possible implementations, the curves of the position calibration quantities detected by each of the two TMR angle sensors changing with the lens stroke are determined based on the curves of the components of the magnetic field strength in two directions detected by each of the two TMR angle sensors changing with the lens stroke and the formula sin(arctan(Bz, Bx)), wherein Bz and Bx respectively represent the components of the magnetic field strength detected by the TMR angle sensor along the direction of the lens movement and along the direction of the positioning magnet toward the TMR angle sensor.

[0012] In some possible implementations, the distance of the positioning magnet along the moving direction of the lens ranges from 2 mm to 3 mm.

[0013] In some possible implementations, the distance between the positioning magnets along the lens moving direction is 2.45 mm.

[0014] In some possible implementations, the distance between the two positioning magnets ranges from 1 mm to 1.5 mm.

[0015] In some possible implementations, the distance between the two positioning magnets is 1 mm.

[0016] In some possible implementations, the distance between the positioning magnets along the two-pole direction ranges from 0.5 mm to 1 mm.

[0017] In some possible implementations, the distance between the positioning magnets along the two-pole direction is 0.8 mm.

[0018] In some possible implementations, the distance between the positioning magnet and the TMR angle sensor along the direction of the two poles of the positioning magnet ranges from 0.5 mm to 1 mm.

[0019] In some possible implementations, the distance between the positioning magnet and the TMR angle sensor along the direction of the two poles of the positioning magnet is in the range of 0.8 mm.

[0020] In some possible embodiments, the voice coil motor also includes a driving magnet and a driving coil, the driving magnet is disposed on the camera module, and the driving coil is disposed on the lens, and the driving component is used to control the current passing through the driving coil so that the driving coil cooperates with the driving magnet to drive the lens to move.

[0021] In some possible implementations, the voice coil motor further includes a lens barrel, the lens barrel is used to mount the lens, and the driving coil and the positioning magnet are respectively disposed on the lens barrel.

[0022] This application also provides:

[0023] A camera module comprises the voice coil motor, a lens, an image sensor and a housing, wherein the lens and the image sensor are respectively arranged in the housing, and the two TMR angle sensors are respectively arranged on the housing.

[0024] In addition, the present application also provides an electronic device, including the camera module.

[0025] The beneficial effects of the present application are as follows: the present application proposes a voice coil motor, a camera module and an electronic device, wherein the camera module includes the voice coil motor, and the electronic device includes the camera module. By respectively arranging two TMR angle sensors and two positioning magnets on the camera module and the lens, through the cooperation of the two positioning magnets and the two TMR angle sensors, when the lens moves over a long stroke, long-stroke feedback control of the lens exceeding 4000um can be achieved, thereby meeting the demand for precise closed-loop control of the lens movement, thereby ensuring the accuracy of shooting. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of a camera module is shown;

[0028] Figure 2 Shows Figure 1 Schematic diagram of the feedback control structure of the voice coil motor of the camera module;

[0029] Figure 3 Shows Figure 2 Schematic diagram of the structure of the TMR angle sensor;

[0030] Figure 4 The graphs showing the change of the magnetic field strength along the x-axis direction and the z-axis direction detected by the two TMR angle sensors respectively with the travel of the lens barrel are shown;

[0031] Figure 5 A curve diagram showing the change of the position calibration amount detected by the two TMR angle sensors respectively with the travel of the lens barrel is shown;

[0032] Figure 6 A curve diagram showing the change of the position calibration amount detected by two TMR angle sensors together with the travel of the lens barrel is shown;

[0033] Figure 7 A structural schematic diagram of an electronic device is shown.

[0034] Description of main component symbols:

[0035] 100-camera module; 10-voice coil motor; 11-lens barrel; 12-positioning magnet; 13-TMR angle sensor; 14-driving assembly; 20-lens; 21-lens; 30-housing; 40-reflector; 50-lens motor; 200-electronic device; 201-housing. DETAILED DESCRIPTION

[0036] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0037] In the description of the present application, it should be understood that the terms "length", "width", "thickness", "inside", "outside", etc. indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0039] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] Embodiment 1

[0041] The present embodiment provides a voice coil motor 10 that can be used in electronic devices. Specifically, the voice coil motor 10 is used to control a lens 20 of a camera module 100 in the electronic device, so as to achieve continuous zooming by driving the lens 20 to move over a long stroke.

[0042] In some embodiments, the electronic device may be a mobile phone, a tablet computer, a laptop computer, a PDA, a desktop computer, a smart watch, a car computer, a set-top box, a smart TV, a digital camera, or the like.

[0043] See also Figure 1 and Figure 2 A camera module 100 includes a voice coil motor 10, a lens 20, an image sensor and a housing 30. The voice coil motor 10, the lens 20 and the image sensor are respectively arranged in the housing 30. The voice coil motor 10 is used to control the movement of the lens 20 to zoom. The image sensor is arranged on a side of the housing 30 away from the incident light. The image sensor is used to receive the light entering through the lens 20 to obtain image information.

[0044] The lens 20 is composed of a plurality of lenses 21. The optical axes of the plurality of lenses 21 coincide with each other, and the optical axes pass through the image sensor.

[0045] In some embodiments, the lens 20 is composed of three lenses 21 , wherein two lenses 21 are fixed on the housing 30 , and another lens 21 is disposed on the voice coil motor 10 and is zoomed by the control of the voice coil motor 10 .

[0046] Please also see Figure 2 The voice coil motor 10 includes a lens barrel 11, a driving magnet, a driving coil, two positioning magnets 12, two TMR angle sensors 13 (Tunnel magnetoresistance effect Angle Sensor) and a driving component 14.

[0047] The lens barrel 11, the driving magnet, the driving coil and the driving assembly 14 are used to drive the movement of the lens 20. The two positioning magnets 12 and the two TMR angle sensors 13 are used to provide feedback on the position of the lens 20, so that the position of the lens 20 is adjusted by the driving assembly 14 to achieve closed-loop feedback control.

[0048] Specifically, the lens barrel 11 is used to mount the lens 21. The driving magnet is disposed in the housing 30. The driving coil is wound around the lens barrel 11. The driving assembly 14 allows current to pass through the driving coil, and controls the driving coil to generate a force, so that the driving coil cooperates with the driving magnet to push the lens barrel 11 on which the lens 21 is mounted to move, and the driving assembly 14 controls the current passing through the driving coil to control the movement of the lens 21, so that the lens 21 moves to the target position to complete focusing.

[0049] In some embodiments, the lens 21 can be fixedly connected to the lens barrel 11 by means of adhesive. However, the present invention is not limited thereto, and the lens 21 can also be fixedly connected to the lens barrel 11 by means of injection molding, clamping, thread connection, interference fit, etc.

[0050] Two positioning magnets 12 are respectively arranged on the lens barrel 11. Two TMR angle sensors 13 are respectively arranged in the housing 30. The two positioning magnets 12 move linearly with the movement of the lens barrel 11. The TMR angle sensor 13 determines the position of the lens barrel 11 by sensing the change of magnetic field strength caused by the movement of the positioning magnets 12, and feeds back to the driving component 14, so that the position of the lens 21 is feedback-adjusted through the driving component 14.

[0051] The opposite magnetic poles on the two positioning magnets 12 are arranged opposite to each other along the direction in which the lens moves. That is, the N pole on one of the positioning magnets 12 is opposite to the S pole on the other positioning magnet 12, and the S pole on one of the positioning magnets 12 is opposite to the N pole on the other positioning magnet 12.

[0052] In some embodiments, the TMR angle sensor 13 is disposed on the bottom plate of the housing 30 .

[0053] like Figure 2 As shown, a Cartesian coordinate system is established, and the z-axis direction is defined as the direction in which the positioning magnet 12 moves with the lens barrel 11, that is, the length direction of the positioning magnet 12; the x-axis direction is defined as the direction in which the positioning magnet 12 faces the TMR angle sensor 13, that is, the width direction of the positioning magnet 12; and the y-axis direction is defined as the direction in which the two poles of the positioning magnet 12 face each other, that is, the thickness direction of the positioning magnet 12. It can be understood that the above definitions are only for the purpose of facilitating the understanding of the relative positional relationship of the components in the input structure, and should not be construed as a limitation to the present application.

[0054] In some embodiments, the N pole of the positioning magnet 12 close to the negative direction of the z-axis faces the positive direction of the y-axis, and the N pole of the positioning magnet 12 close to the positive direction of the z-axis faces the negative direction of the y-axis. However, it is not limited thereto. In other embodiments, the N pole of the positioning magnet 12 close to the negative direction of the z-axis may also face the negative direction of the y-axis, and correspondingly, the N pole of the positioning magnet 12 close to the positive direction of the z-axis faces the positive direction of the y-axis.

[0055] like Figure 3 As shown, the sensing point on the TMR angle sensor 13 is located on a surface of the TMR angle sensor 13 facing the positive direction of the y-axis, and is located at the center of the surface. The sensing point can sense the two components of the magnetic field intensity of the point horizontal to the surface, namely the magnetic field intensity component in the x-direction and the magnetic field intensity component in the z-direction.

[0056] See also Figure 2 In this embodiment, the TMR angle sensor 13 is located on the side of the positioning magnet 12 that deviates from the x-axis and the y-axis, that is, the TMR angle sensor 13 deviates from both the direction of the two poles of the positioning magnet 12 and the width direction of the positioning magnet 12. The TMR angle sensor 13 can detect the magnetic field intensity components in the x-axis direction and along the z-axis direction during the movement of the positioning magnet 12, and obtain the position of the positioning magnet 12 by calculation, thereby obtaining the position of the lens barrel 11, that is, the position of the lens 21.

[0057] Please also see Figures 4 to 6 , where the horizontal coordinates of the three coordinate systems are the moving stroke of the lens barrel 11, in mm, and the vertical coordinates are the magnetic induction intensity (in mT), the position calibration amount of a single TMR angle sensor, and the common position calibration amount of two TMR angle sensors. The specific calculation is as follows:

[0058] like Figure 4 As shown, the four curves in the figure are respectively curves of the magnetic field strength Bx and Bz of the positioning magnet 12 in the x-axis direction and the z-axis direction detected by the two TMR angle sensors 13 respectively as the travel of the lens barrel 11 changes.

[0059] Wherein, Bx and Bz represent the strength of the magnetic field along the x-axis and z-axis respectively.

[0060] like Figure 5 As shown, according to Figure 4 The two curves calculated by the curve data and the formula sin(arctan(Bz, Bx)) are respectively curves of the change of the position calibration amount detected by the two TMR angle sensors 13 with the travel of the lens barrel 11.

[0061] like Figure 6 As shown, according to Figure 5 The curve data and the formula arctan(TMR1, TMR2) are used to calculate a curve with good linearity in the middle part, which is a curve showing the change of the position calibration quantity detected by the two TMR angle sensors 13 with the travel of the lens barrel 11.

[0062] Wherein, TMR1 and TMR2 respectively represent the position calibration quantities detected by the two TMR angle sensors 13 .

[0063] like Figure 6 As shown, the linear mapping relationship between the obtained travel of the lens barrel 11 and the position calibration amount is good.

[0064] Through the cooperation of the two positioning magnets 12 and the two TMR angle sensors 13, feedback control of the lens barrel 11 over a stroke of more than 4000um can be achieved, and the long-stroke feedback closed-loop positioning of the lens 21 can be achieved. In addition, the positioning magnet 12 is simple in design and occupies a small space, meeting the requirements of small size and high reliability of the mobile phone camera module 100.

[0065] In some embodiments, the coordinates of the two positioning magnets 12 in the y-axis direction are the same, that is, the two positioning magnets 12 are in the same xz plane, so that the magnetic field changes generated by them are simple, which facilitates simplified calculations and improves response speed.

[0066] In some embodiments, the two positioning magnets 12 are arranged side by side along the moving direction of the lens barrel 11, that is, the z-axis direction, so that the magnetic field changes generated by them are simple, so as to simplify the calculation and improve the response speed.

[0067] In some embodiments, the two TMR angle sensors 13 are arranged side by side along the moving direction of the lens barrel 11 to simplify calculation and improve response speed.

[0068] Initially, the two TMR angle sensors 13 are located on one side of the positioning magnet 12 along the z-axis direction.

[0069] In some embodiments, the positioning magnet 12 is in an elongated shape, and its length direction is consistent with the moving direction of the lens barrel 11, so that its position can be flexibly adjusted when it is set on the lens barrel 11, and the circuits and other components in the camera module 100 can be avoided when the positioning magnet 12 moves with the lens barrel 11.

[0070] In some embodiments, the positioning magnet 12 can be directly disposed on the outer wall of the lens barrel 11 to facilitate adjustment of its position. However, the positioning magnet 12 can also be directly fixed on the outer wall of the lens barrel 11 according to the design, such as by embedding or integral molding; the positioning magnet 12 can also be disposed in or inside the lens barrel 11 according to design requirements.

[0071] In some embodiments, the distance of the positioning magnet 12 along the z-axis direction, that is, the length of the positioning magnet 12 ranges from 2 mm to 3 mm.

[0072] Preferably, the length of the positioning magnet 12 is 2.45 mm.

[0073] In some embodiments, the distance between the two positioning magnets 12 along the z-axis direction, that is, the distance D1 between the two positioning magnets 12 is in the range of 1 mm-1.5 mm.

[0074] Preferably, the distance D1 between the two positioning magnets 12 is 1 mm.

[0075] In some embodiments, the distance of the positioning magnet 12 along the y-axis direction, that is, the thickness of the positioning magnet 12 ranges from 0.5 mm to 1 mm.

[0076] Preferably, the thickness of the positioning magnet 12 is 0.8 mm.

[0077] In some embodiments, there is a distance between the positioning magnet 12 and the TMR angle sensor 13 along the y-axis direction, that is, there is a spacing D2 along the thickness direction of the positioning magnet 12, and the range of the spacing D2 is 0.5 mm-1 mm.

[0078] Preferably, the distance D2 is 0.8 mm.

[0079] In some embodiments, there is a distance between the positioning magnet 12 and the sensing point of the TMR angle sensor 13 along the x-axis direction, that is, there is a spacing D3 along the width direction of the positioning magnet 12, and the range of the spacing D3 is 0 mm-0.5 mm.

[0080] Preferably, the distance D3 is 0.3 mm.

[0081] Since the positioning magnet 12 is added to the lens barrel 11, the weight distribution on the lens barrel 11 is changed, which will lead to uneven weight on the lens barrel 11, resulting in inconsistent movement of the drive coil and the drive magnet when driving the lens barrel 11 to move, resulting in unilateral focus blur. In order to avoid the above problems, it is necessary to adjust the weight when designing the lens barrel 11 so that the center of gravity of the lens barrel 11 including the drive coil, the lens 21 and the positioning magnet 12 is on the central axis of the lens 21.

[0082] In some embodiments, a guide shaft may be further provided in the voice coil motor 10 , and the guide shaft extends along the moving direction of the lens barrel 11 and passes through the lens barrel 11 , so that the movement of the lens barrel 11 is more stable.

[0083] In other embodiments, a guide groove may be further provided on the lens barrel 11, and a guide rail may be provided on the shell 30 relative to the guide groove; or a guide rail may be provided on the lens barrel 11, and a guide groove may be provided on the shell 30 relative to the guide rail. The movement of the lens barrel 11 may be smoother through the cooperation between the guide rail and the guide groove.

[0084] It can be understood that in some embodiments, one TMR angle sensor 13 can be replaced by two angle sensors measuring different directions, and it is only necessary to ensure that the sensing point positions of the two angle sensors measuring different directions remain consistent.

[0085] In this embodiment, initially, the two TMR angle sensors 13 are located on one side of the positioning magnet 12 along the z-axis direction. It can be understood that in other embodiments, in order to further increase the detection distance, two more TMR angle sensors 13 can be arranged on the other side of the moving direction of the positioning magnet 12, thereby increasing the stroke of the closed-loop feedback control.

[0086] In this embodiment, the TMR angle sensor 13 is disposed in the housing 30, and the positioning magnet 12 is disposed on the lens barrel 11. It can be understood that in other embodiments, the TMR angle sensor 13 can also be disposed on the lens barrel 11, and the positioning magnet 12 can be disposed in the housing 30, and closed-loop feedback control can also be performed.

[0087] The driving component 14 can receive a first driving signal issued by the electronic device 200 and control the driving coil to be energized, thereby pushing the lens 21 to move; after the two TMR angle sensors 13 sense the magnetic field of the positioning magnet 12, they generate a second driving signal. The driving component 14 can also receive the second driving signal and control the driving coil to be energized, thereby pushing the lens 21 and adjusting it to the target position, thereby completing closed-loop feedback focusing.

[0088] In this embodiment, by respectively arranging two TMR angle sensors 13 and two positioning magnets 12 on the housing 30 of the camera module 100 and the lens barrel 11, positioning feedback can be performed on the moving position of the lens barrel 11 when the lens barrel 11 moves for a long stroke, and the feedback stroke is relatively long, which meets the precise closed-loop control requirements of the continuous zoom camera module 100 for the movement of the lens, thereby ensuring the accuracy of the shooting. In addition, the positioning magnet 12 is simple in design and installation, occupies a small space, meets the requirements of the mobile phone camera module 100 for small size and high reliability, and is conducive to the development of thin and light electronic equipment.

[0089] Embodiment 2

[0090] See also Figures 1 to 6The camera module 100 provided in this embodiment can be applied to electronic devices. This embodiment is an improvement made on the technical basis of the above embodiment 1. Compared with the above embodiment 1, the difference is that:

[0091] In this embodiment, the camera module 100 further includes a reflector 40 and a lens motor 50. The reflector 40 is rotatably disposed on the light incident side of the housing 30. The lens motor 50 is connected to the reflector 40. The lens motor 50 is used to drive the reflector 40 to rotate.

[0092] In this embodiment, the camera module 100 is a periscope camera module. The angles between the reflector 40 and the incident light and the optical axis are all acute angles.

[0093] Preferably, the initial angles between the reflector 40 and the incident light and the optical axis are all 45°, so as to facilitate the quick use of the camera module 100.

[0094] Embodiment 3

[0095] See also Figures 1 to 7 The electronic device 200 provided in this embodiment includes a housing 201 and a camera module 100 as described in any one of the first embodiment or the second embodiment. The camera module 100 is disposed on the housing 201 .

[0096] In some embodiments, the electronic device 200 may be a mobile phone, and the user may take pictures through the camera module 100 and control the camera module 100 to achieve a fast continuous zoom function, making shooting more convenient and having high focusing accuracy, better clarity and precision.

[0097] In other embodiments, the electronic device 200 may also be a tablet computer, a laptop computer, a smart watch, a desktop computer, a PDA, a car computer, a set-top box, a smart TV, a digital camera, and the like.

[0098] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0099] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A voice coil motor, characterized in that: Used to control the movement of the lens in the camera module, including: Two positioning magnets are respectively arranged on the lens along the direction in which the lens moves, and opposite magnetic poles on the two positioning magnets are arranged opposite to each other along the direction in which the lens moves; Two TMR angle sensors are respectively arranged on the camera module along the direction of movement of the lens, and the two TMR angle sensors are used to detect the components of the magnetic field strength along the direction of movement of the lens and in the direction of the positioning magnet toward the TMR angle sensors during the movement of the positioning magnet. The two TMR angle sensors determine the position calibration amount detected by the two TMR angle sensors according to the components of the magnetic field strength in the two directions detected, and thereby determine the position of the positioning magnet; and The driving assembly is used to adjust the position of the lens according to the position of the positioning magnet.

2. The voice coil motor according to claim 1, characterized in that: The two TMR angle sensors determine the position calibration quantity detected jointly by the two TMR angle sensors based on the components of the magnetic field strength in the two directions detected, and determine the position of the positioning magnet based on the change curve of the position calibration quantity detected jointly by the two TMR angle sensors along the lens stroke.

3. The voice coil motor according to claim 2, characterized in that: The curve of the position calibration quantity jointly detected by the two TMR angle sensors changing with the lens stroke is determined according to the curve of the position calibration quantity individually detected by the two TMR angle sensors changing with the lens stroke and the formula arctan(TMR1, TMR2), wherein TMR1 and TMR2 respectively represent the position calibration quantities detected by the two TMR angle sensors respectively.

4. The voice coil motor according to claim 3, characterized in that: The curves of the position calibration quantities detected by each of the two TMR angle sensors changing with the lens stroke are determined based on the curves of the components of the magnetic field strength in two directions detected by each of the two TMR angle sensors changing with the lens stroke and the formula sin(arctan(Bz, Bx)), wherein Bz and Bx respectively represent the components of the magnetic field strength detected by the TMR angle sensor along the direction of the lens movement and along the direction of the positioning magnet toward the TMR angle sensor.

5. The voice coil motor according to claim 1, characterized in that: The distance of the positioning magnet along the moving direction of the lens is in the range of 2mm-3mm.

6. The voice coil motor according to claim 5, characterized in that: The distance between the positioning magnets along the moving direction of the lens is 2.45 mm.

7. The voice coil motor according to claim 1, characterized in that: The distance between the two positioning magnets ranges from 1 mm to 1.5 mm.

8. The voice coil motor according to claim 7, characterized in that: The distance between the two positioning magnets is 1 mm.

9. The voice coil motor according to claim 1, characterized in that: The distance between the positioning magnets along the two-pole direction ranges from 0.5 mm to 1 mm.

10. The voice coil motor according to claim 9, characterized in that: The distance between the positioning magnets along the two-pole direction is 0.8 mm.

11. The voice coil motor according to claim 1, characterized in that: The distance between the positioning magnet and the TMR angle sensor along the direction of the two poles of the positioning magnet ranges from 0.5 mm to 1 mm.

12. The voice coil motor according to claim 11, characterized in that: The distance between the positioning magnet and the TMR angle sensor along the direction of the two poles of the positioning magnet is in the range of 0.8 mm.

13. The voice coil motor according to claim 1, characterized in that: The voice coil motor also includes a driving magnet and a driving coil. The driving magnet is arranged on the camera module, and the driving coil is arranged on the lens. The driving component is used to control the current passing through the driving coil so that the driving coil cooperates with the driving magnet to drive the lens to move.

14. The voice coil motor according to claim 13, characterized in that: The voice coil motor further comprises a lens barrel, which is used for mounting the lens, and the driving coil and the positioning magnet are respectively arranged on the lens barrel.

15. A camera module, characterized in that: It comprises the voice coil motor, lens, image sensor and housing as described in any one of claims 1 to 14, wherein the lens and the image sensor are respectively arranged in the housing, and the two TMR angle sensors are respectively arranged on the housing.

16. An electronic device, characterized in that: Including the camera module as described in claim 15.

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