Ball-type image stabilization motor and electronic device

Abstract

The present application relates to the technical field of imaging. Disclosed are a ball-type image stabilization motor and an electronic device. The ball-type image stabilization motor in the present application comprises: a first mover, a second mover, a first ball, a second ball, a first detection unit, a second detection unit, a circuit board and a base, wherein by means of the first ball, the first mover undergoes relative displacement with respect to the base in the direction of focus; by means of the second ball, the second mover undergoes relative displacement with respect to the base in the direction of shake, the direction of shake being perpendicular to the direction of focus; the circuit board is arranged on a side wall of the base; and the first detection unit and the second detection unit are both arranged on the circuit board, the first detection unit being used for detecting the movement of the first mover, and the second detection unit being used for detecting the movement of the second mover; one of the first detection unit and the second detection unit is a capacitive detection unit, and the other is a magnetic-field detection unit. The detection accuracy of the magnetic-field detection unit for displacement detection is improved.

Description

A ball-type anti-shake motor and electronic device Cross-references

[0001] This disclosure claims priority to Chinese patent application No. 202520562257X, filed on March 27, 2025, entitled "A Ball-Type Anti-Shake Motor and Electronic Device", which is incorporated herein by reference in its entirety. Technical Field

[0002] This application relates to the field of camera technology, and in particular to a ball bearing type image stabilization motor and electronic device. Background Technology

[0003] A ball-type image stabilization motor uses electromagnetic force to drive balls to roll in grooves on a mover, thereby moving the mover and counteracting displacement deviations caused by external vibrations in real time, thus achieving focusing and optical image stabilization. During focusing and image stabilization operations, a magnet and a Hall sensor are typically used in conjunction to detect the displacement in order to determine the distance the mover has traveled.

[0004] However, current ball-bearing image stabilization motors have at least the following drawbacks: Because the moving part displaces in multiple directions during image stabilization and focusing, at least three sets of magnets and Hall sensors are typically used to detect displacement in three different directions to achieve comprehensive image stabilization. The magnetic fields generated by the multiple sets of magnets in the motor interfere with each other, causing deviations in the Hall sensor's detection results, especially crosstalk between image stabilization and focusing, affecting the final focusing and image stabilization performance. Summary of the Invention

[0005] The purpose of this application is to provide a ball-bearing image stabilization motor and an electronic device. By setting different types of displacement detection units in the motor to detect the displacement in the focusing and image stabilization directions, the magnetic fields generated by multiple sets of detection units are avoided from interfering with each other, thereby improving the accuracy of displacement detection and thus improving the overall focusing and image stabilization effect of the motor.

[0006] To address the aforementioned technical problems, embodiments of this application provide a ball-type image stabilization motor, comprising: a first mover, a second mover, a first ball, a second ball, a first detection unit, a second detection unit, a circuit board, and a base; the first mover utilizes the first ball to generate relative displacement with the base in the focusing direction; the second mover utilizes the second ball to generate relative displacement with the base in the shaking direction; wherein, the shaking direction is perpendicular to the focusing direction; the circuit board is disposed on the side wall of the base; the first detection unit and the second detection unit are both disposed on the circuit board, the first detection unit is used to detect the movement of the first mover, and the second detection unit is used to detect the movement of the second mover; wherein, one of the first detection unit and the second detection unit is a capacitive detection unit, and the other is a magnetic field detection unit.

[0007] Embodiments of this application also provide an electronic device, including the ball-type anti-shake motor described above.

[0008] Compared to existing technologies, the ball-bearing image stabilization motor in this application embodiment is equipped with a first mover and a second mover that move in different directions. The first mover moves in the focusing direction of the motor via a first ball, and the second mover moves in the shaking direction of the motor via a second ball. The movement of the first mover is detected by a first detection unit on a circuit board mounted on the side wall of the base, and the movement of the second mover is detected by a second detection unit. The first and second detection units are configured as different types of detection units. One detection unit is a capacitive detection unit, which determines the displacement based on changes in the electric field, and the other is a magnetic field detection unit, which determines the displacement based on changes in the magnetic field. The detection conditions of the first and second detection units are different, so the detection results of the first and second detection units do not affect each other. This ensures that the detection of focusing displacement and the detection of image stabilization displacement do not interfere with each other, improves the detection accuracy of the magnetic field detection unit, and thus improves the overall focusing and image stabilization effect of the motor.

[0009] In addition, the first detection unit is a capacitive detection unit, and the second detection unit is a magnetic field detection unit.

[0010] In addition, the first detection unit includes: a floating electrode plate disposed on the first mover, and an emitting electrode plate and a receiving electrode plate disposed on the circuit board; the floating electrode plate is disposed opposite to the emitting electrode plate, and the floating electrode plate is disposed opposite to the receiving electrode plate; when the first mover moves in the focusing direction, the facing area of ​​the floating electrode plate and the receiving electrode plate changes, and the facing area of ​​the floating electrode plate and the emitting electrode plate remains unchanged.

[0011] In addition, there are two receiving plates; the two receiving plates are arranged sequentially in the focusing direction; when the first mover moves in the focusing direction, the first change in the area of ​​the floating plate facing one of the receiving plates is equal to the second change in the area of ​​the floating plate facing the other receiving plate.

[0012] In addition, the second detection unit includes: a detection magnet disposed on the second mover, and a first magnetic field sensor disposed on the circuit board; the detection magnet is disposed opposite to the first magnetic field sensor; when the second mover moves in the shaking direction, the distance between the detection magnet and the first magnetic field sensor changes accordingly.

[0013] In addition, the ball bearing anti-shake motor also includes: a drive unit; the drive unit includes: a drive magnet disposed on the second mover and a drive coil disposed on the base, the drive magnet and the drive coil being disposed opposite to each other; the second detection unit includes: a second magnetic field sensor disposed on the circuit board; the second magnetic field sensor and the drive magnet being disposed opposite to each other; when the second mover moves in the shaking direction, the distance between the drive magnet and the second magnetic field sensor changes accordingly.

[0014] In addition, there are multiple second magnetic field sensors, and all of the multiple second magnetic field sensors are within the magnetic field range of the driving magnet.

[0015] In addition, the second magnetic field sensor is a Hall sensor or a tunnel magnetoresistive (TMR) sensor.

[0016] In addition, the ball bearing image stabilization motor also includes: a pressure cap that fits against the second mover; the pressure cap abuts against the second mover in the focusing direction, restricting the movement of the second mover in the focusing direction. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0018] Figure 1 is an exploded structural diagram of the ball bearing anti-shake motor according to an embodiment of this application;

[0019] Figure 2 is a schematic diagram of the structure of the first detection unit in the ball-type anti-shake motor according to an embodiment of this application;

[0020] Figure 3 is a schematic diagram of the independent structure of the first detection unit in the ball bearing anti-shake motor according to an embodiment of this application;

[0021] Figure 4 is a schematic diagram of the structure of the second detection unit in the ball-type anti-shake motor according to an embodiment of this application;

[0022] Figure 5 is a schematic diagram of the structure of the second detection unit in a ball-type anti-shake motor according to another embodiment of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of this application to enable readers to better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0024] The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0025] This application relates to a ball bearing image stabilization motor, as shown in FIG1. ​​The ball bearing image stabilization motor includes: a circuit board 1, a base 2, a first mover 31, a second mover 32, a first ball bearing 41, a second ball bearing 42, a first detection unit, and a second detection unit. The first mover 31 is relatively displaced relative to the base 2 in the focusing direction (Z-axis direction shown in FIG1) by means of the first ball bearing 41. The second mover 32 is relatively displaced relative to the base 1 in the shaking direction (X-axis and Y-axis directions shown in FIG1) by means of the second ball bearing 42. The shaking direction is perpendicular to the focusing direction. The circuit board 1 is disposed on the side wall of the base 2. The first detection unit and the second detection unit are both disposed on the circuit board 1. The first detection unit is used to detect the movement of the first mover 31, and the second detection unit is used to detect the movement of the second mover 32. One of the first detection unit and the second detection unit is a capacitive detection unit, and the other is a magnetic field detection unit.

[0026] Compared to existing technologies, the ball-bearing image stabilization motor in this application embodiment is equipped with a first mover and a second mover that move in different directions. The first mover moves in the focusing direction of the motor via a first ball, and the second mover moves in the shaking direction of the motor via a second ball. The movement of the first mover is detected by a first detection unit on a circuit board mounted on the side wall of the base, and the movement of the second mover is detected by a second detection unit. The first and second detection units are configured as different types of detection units. One detection unit is a capacitive detection unit, which determines the displacement based on changes in the electric field, and the other is a magnetic field detection unit, which determines the displacement based on changes in the magnetic field. The detection conditions of the first and second detection units are different, so the detection results of the first and second detection units do not affect each other. This ensures that the detection of focusing displacement and the detection of image stabilization displacement do not interfere with each other, improves the detection accuracy of the magnetic field detection unit, and thus improves the overall focusing and image stabilization effect of the motor.

[0027] Considering that the detection accuracy of capacitive and electromagnetic detection units may differ due to environmental influences, higher-accuracy detection units can be set as detection units with higher usage frequency, while lower-accuracy detection units can be set as detection units with lower usage frequency, thereby enabling the device to achieve better overall detection performance.

[0028] Taking a capacitive detection unit as the first detection unit and a magnetic field detection unit as the second detection unit as an example, the structural configuration of the first and second detection units will be explained in detail:

[0029] As shown in Figure 2, the first detection unit 5 includes: a floating electrode plate 51 disposed on the first mover 31, and an emitting electrode plate 52 and a receiving electrode plate 53 disposed on the circuit board 1; the floating electrode plate 51 and the emitting electrode plate 52 are disposed opposite each other in a direction perpendicular to the focusing direction, and the floating electrode plate 51 and the receiving electrode plate 53 are disposed opposite each other; when the first mover 31 moves in the focusing direction, the facing area of ​​the floating electrode plate 51 and the receiving electrode plate 53 changes, while the facing area of ​​the floating electrode plate 51 and the emitting electrode plate 52 remains unchanged.

[0030] The capacitor formed by the floating plate 51, the emitting plate 52, and the receiving plate 53 can be considered as the sum of the capacitors formed by the emitting plate 52 and the floating plate 51, and the capacitors formed by the floating plate 51 and the receiving plate 53. Each capacitor is represented by the physical formula for a parallel plate capacitor: C = εS / 4πkd; where ε represents the dielectric constant of the medium, determined by the medium between the plates, such as air or water; and k represents the electrostatic constant, also known as the Coulomb constant, which indicates that the force between two point charges, each with a charge of 1C, separated by a distance of 1m in a vacuum is 8.987551 × 10⁻⁶. 9N, i.e., k = 8.987551 × 10 9 N·m 2 / C; S represents the area (projected area) of the two plates facing each other; d represents the vertical distance between the two plates; π represents pi. Therefore, when the area of ​​the floating plate 51 and the transmitting plate 52 facing each other remains constant, the capacitance signal changes according to the area of ​​the floating plate 51 and the receiving plate 53 facing each other. Since the change in the area of ​​the floating plate 51 and the receiving plate 53 facing each other is related to the distance the first mover moves in the focusing direction, the distance the first mover moves in the focusing direction can be known from the change in the capacitance signal.

[0031] The first detection unit contains two receiving plates 53; the two receiving plates 53 are arranged sequentially in the focusing direction; when the first mover 31 moves in the focusing direction, the first change in the area of ​​the floating plate 51 facing one of the receiving plates 53 is equal to the second change in the area of ​​the floating plate 51 facing the other receiving plate 53. That is, the decrease in the area of ​​the floating plate facing one of the receiving plates is the same as the increase in the area of ​​the floating plate facing the other receiving plate, or the increase in the area of ​​the floating plate facing one of the receiving plates is the same as the decrease in the area of ​​the floating plate facing the other receiving plate. This design facilitates subsequent differential calculation of the capacitance signal for correction or noise reduction, eliminating noise that affects the accuracy of the calculation results due to environmental factors or human operation, while improving the sensitivity of lens position movement control. The differential calculation formula can be: amplification factor × (CX1-CX2) / (CX1+CX2); where CX1 represents the capacitance signal formed by the floating electrode and one of the receiving electrodes, and CX2 represents the capacitance signal formed by the floating electrode and the other receiving electrode.

[0032] The capacitor structure composed of the floating electrode 51, the emitting electrode 52, and the two receiving electrodes 53 is shown in Figure 3. The size of the floating electrode 51 is smaller than the size of the area covered by the emitting electrode 52 and the two receiving electrodes 53. This ensures that during the process of the first mover driving the floating electrode 51 to move in the focusing direction, the floating electrode 51 is always within the area covered by the emitting electrode 52 and the two receiving electrodes 53. That is, during the movement of the floating electrode 51, the edge of the floating electrode 51 will never exceed the edge of the emitting electrode 52, and the edge of the floating electrode 51 will also never exceed the edge of the receiving electrode 53.

[0033] Furthermore, the structure of the second detection unit is shown in Figure 4. The second detection unit 6 includes: a detection magnet 61 disposed on the second mover 32, and a first magnetic field sensor 62 disposed on the circuit board; the detection magnet 61 and the first magnetic field sensor 62 are disposed opposite each other in a direction perpendicular to the focusing direction; when the second mover 32 moves in the shaking direction, the distance between the detection magnet 61 and the first magnetic field sensor 62 changes accordingly. To improve the detection effect of the first magnetic field sensor 62 on the magnetic field generated by the detection magnet 61, it is best to avoid setting a structure that blocks the propagation of the magnetic field between the first magnetic field sensor 62 and the detection magnet 61. For example, the base 2 between the first magnetic field sensor 62 and the detection magnet 61 can be set as a hollow structure, that is, the base 2 is a frame structure with a hollowed-out middle area, which ensures that the base 2 can play a supporting role while reducing the obstruction of the magnetic field by the base 2. The first magnetic field sensor can be a Hall sensor or a tunnel magnetoresistive (TMR) sensor.

[0034] Since the second mover 32 moves in two directions, namely the X-axis and Y-axis directions as shown in Figure 4, to ensure the accuracy of displacement detection, a second detection unit can be set in each direction of movement. Both sets of second detection units include a first magnetic field sensor 62 and a detection magnet 61. The detection magnets 61 in different sets of second detection units are respectively set on different sides of the second mover 32, as shown in Figure 4. The detection magnets 61 in the two sets of second detection units are respectively set on adjacent sides of the second mover 32, and the first magnetic field sensor in each set of second detection units is set at the relative position of the detection magnet in that set. There can be multiple first magnetic field sensors in each set of second detection units. By performing differential processing on the detection results of multiple first magnetic field sensors, the detection accuracy of the first magnetic field sensor can be improved.

[0035] Additionally, as shown in Figure 4, the ball-type anti-shake motor itself includes a drive unit 9 comprising a drive magnet 92 mounted on the second mover 32 and a drive coil 93 mounted on the base, with the drive magnet and drive coil positioned opposite each other. The drive magnet 92 forms a fixed magnetic field around the second mover 32. The drive coil 93 is connected to a circuit board and powered and controlled by an external circuit and IC. When the drive coil 93 is energized, it generates an induced magnetic field, which interacts with the fixed magnetic field formed by the drive magnet 92 to produce a Lorentz force. Since the drive coil 93 is fixed to the base 2 and cannot move, the Lorentz force is fed back to the drive magnet 92. Due to the presence of the second ball, the carrier of the drive magnet 92, the second mover 32, can move relative to the base, thereby driving the second mover. By changing the current in the drive coil 92, the magnitude of the Lorentz force can be controlled, thus changing the force on the second mover and controlling the distance of movement.

[0036] To avoid the influence of the fixed magnetic field generated by the driving magnet on the detection results of the first magnetic field sensor, the first magnetic field sensor can be spaced apart from the driving magnet. Similarly, the first magnetic field sensor also needs to be spaced apart from the driving coil. The first magnetic field sensor determines the displacement of the second mover by using a separately set detection magnet for detecting the movement of the second mover, which can improve the detection accuracy of the first magnetic field sensor.

[0037] Furthermore, to improve the reuse rate of components in the ball-type anti-shake motor and save costs, the detection magnet in the second detection unit can be replaced by the driving magnet of the drive unit. As shown in Figure 5, the second detection unit includes: a second magnetic field sensor 63 mounted on a circuit board; the second magnetic field sensor 63 and the driving magnet 92 are positioned opposite each other; when the second mover 32 moves in the shaking direction, the distance between the driving magnet 92 and the second magnetic field sensor 63 changes accordingly. In this case, the driving magnet serves both to implement the driving function and to cooperate with the second magnetic field sensor to achieve displacement detection. There are multiple second magnetic field sensors, and all of them are within the magnetic field range of the driving magnet. By performing differential processing on the detection results of multiple second magnetic field sensors, the detection accuracy of the second magnetic field sensors is improved.

[0038] The second mover moves in at least two directions (the X-axis and Y-axis directions as shown in Figure 5). Corresponding driving magnets are set in each of these two directions, and one or more second magnetic field sensors are set for each driving magnet in each direction to detect the displacement of the second mover in different directions. The second magnetic field sensors are Hall effect sensors or tunnel magnetoresistive (TMR) sensors.

[0039] In addition to driving the second mover, a driving unit corresponding to the first mover also needs to be set up. As shown in Figure 2, a focusing magnet 91 corresponding to the first mover is set on the side of the first mover 31, and a focusing coil is set at the opposite position of the focusing magnet 91. The focusing coil is connected to the circuit board. The method of controlling the displacement of the first mover by using the focusing magnet 91 and the focusing coil is the same as the driving method of the second mover described above, and will not be repeated here.

[0040] In addition, in order to ensure that the second mover is not driven by the first mover, the second mover only moves in the shaking direction and does not move in the focusing direction. As shown in Figure 1, the ball bearing image stabilization motor also includes a pressure cover 7 that fits against the second mover 32. The pressure cover 7 abuts against the second mover 32 in the focusing direction and restricts the movement of the second mover 32 in the focusing direction.

[0041] In addition, as shown in Figure 1, the ball bearing anti-shake motor also includes a housing 8 that covers the periphery of all component structures, and the housing 8 protects the internal structure of the ball bearing anti-shake motor.

[0042] To reduce the size of the ball bearing image stabilization motor, its internal components can be arranged in an overlapping manner in the focusing direction. For example, the second mover 32 can be placed inside the first mover 31, meaning the first mover 31 is a hollow frame structure with the central area used to accommodate the lens, and the frame surrounds the outer side of the second mover 32. This structure allows the second mover 32 to at least partially overlap with the first mover 31 in the focusing direction, reducing the thickness of the ball bearing image stabilization motor in that direction. Similarly, the base 2 also overlaps at least partially with the first mover 31 in the focusing direction, further reducing the thickness of the ball bearing image stabilization motor in that direction. The circuit board 1 is located on the side wall of the base 2, facilitating the electrical connection between the first and second detection units housed within the ball bearing image stabilization motor. The circuit board 1 can be a flexible printed circuit board (FPC), making it easier to fit the outer surface of the base.

[0043] Another feasible embodiment of this application relates to an electronic device, as shown in FIG5, including the ball-type image stabilization motor as described above. The ball-type image stabilization motor is used in conjunction with a lens to achieve image acquisition and automatically calibrate against vibrations from the external environment, thereby improving the quality of image acquisition.

[0044] Compared with related technologies, the electronic device provided in this application embodiment is equipped with the ball-type anti-shake motor provided in the aforementioned embodiment. Therefore, it also has the technical effects provided in the aforementioned embodiment, and will not be described in detail here.

[0045] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A ball-type anti-shake motor, comprising: First moving part, second moving part, first ball bearing, second ball bearing, first detection unit, second detection unit, circuit board and base; The first moving part uses the first ball to generate relative displacement with the base in the focusing direction; The second moving element utilizes the second ball bearing to achieve relative displacement with the base in the shaking direction; wherein, the shaking direction is perpendicular to the focusing direction; The circuit board is disposed on the side wall of the base; Both the first detection unit and the second detection unit are disposed on the circuit board. The first detection unit is used to detect the movement of the first moving part, and the second detection unit is used to detect the movement of the second moving part. Among them, one of the first detection unit and the second detection unit is a capacitive detection unit and the other is a magnetic field detection unit.

2. The ball bearing anti-shake motor according to claim 1, wherein, The first detection unit is the capacitive detection unit, and the second detection unit is the magnetic field detection unit.

3. The ball bearing anti-shake motor according to claim 2, wherein, The first detection unit includes: a floating electrode plate disposed on the first moving part, and a transmitting electrode plate and a receiving electrode plate disposed on the circuit board; The floating electrode plate is arranged opposite to the transmitting electrode plate, and the floating electrode plate is arranged opposite to the receiving electrode plate; When the first mover moves in the focusing direction, the area of ​​the floating electrode plate facing the receiving electrode plate changes, while the area of ​​the floating electrode plate facing the transmitting electrode plate remains constant.

4. The ball bearing anti-shake motor according to claim 3, wherein, The number of receiving plates is two; The two receiving plates are arranged sequentially in the focusing direction; When the first mover moves in the focusing direction, the first change in the area of ​​the floating electrode plate facing one of the receiving electrodes is equal to the second change in the area of ​​the floating electrode plate facing the other receiving electrode plate.

5. The ball bearing anti-shake motor according to claim 2, wherein, The second detection unit includes: a detection magnet disposed on the second moving part, and a first magnetic field sensor disposed on the circuit board; The detection magnet is positioned opposite to the first magnetic field sensor; When the second mover moves in the shaking direction, the distance between the detection magnet and the first magnetic field sensor changes accordingly.

6. The ball bearing anti-shake motor according to claim 2, wherein, Also includes: Drive unit; The driving unit includes: a driving magnet disposed on the second moving part, and a driving coil disposed on the base, wherein the driving magnet and the driving coil are disposed opposite to each other; The second detection unit includes: a second magnetic field sensor disposed on the circuit board; The second magnetic field sensor is positioned opposite to the driving magnet; When the second mover moves in the shaking direction, the distance between the driving magnet and the second magnetic field sensor changes accordingly.

7. The ball bearing anti-shake motor according to claim 6, wherein, There are multiple second magnetic field sensors, and all of the multiple second magnetic field sensors are within the magnetic field range of the driving magnet.

8. The ball bearing anti-shake motor according to claim 6, wherein, The second magnetic field sensor is a Hall sensor or a tunnel magnetoresistive (TMR) sensor.

9. The ball-type anti-shake motor according to any one of claims 1 to 8, wherein, Also includes: A pressure cap that fits the second moving part; The pressure cap abuts against the second moving part in the focusing direction, restricting the movement of the second moving part in the focusing direction.

10. An electronic device, comprising: The ball bearing anti-shake motor as described in any one of claims 1 to 9.

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