Ball-type anti-shake motor and electronic device

Abstract

The utility model relates to camera technology field discloses a kind of ball type anti-shake motor and electronic equipment.The utility model discloses ball type anti-shake motor includes: first mover, second mover, first ball, second ball, first detection unit, second detection unit, circuit board and base;First mover utilizes first ball and base and occurs relative displacement in focusing direction;Second mover utilizes second ball and base and occurs relative displacement in shaking direction;Wherein, shaking direction is perpendicular to focusing direction;Circuit board is arranged on the side wall of base;First detection unit and second detection unit are all arranged on circuit board, first detection unit is used to detect the moving condition of first mover, and second detection unit is used to detect the moving condition of second mover;Wherein, one of first detection unit and second detection unit is capacitive detection unit, and the other is magnetic field type detection unit.Improves the detection precision of magnetic field type detection unit for displacement detection.

Description

Technical Field

[0001] This utility model relates to the field of camera technology, and in particular to a ball bearing anti-shake motor and electronic device. Background Technology

[0002] 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.

[0003] The inventors discovered that current ball-bearing image stabilization motors have at least the following drawbacks: During image stabilization and focusing, the moving part displaces in multiple directions. To achieve comprehensive image stabilization, at least three sets of magnets and Hall sensors are typically used to detect displacement in three different directions. However, 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. Utility Model Content

[0004] The purpose of this utility model embodiment is to provide a ball bearing type image stabilization motor and 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.

[0005] To solve the above-mentioned technical problems, embodiments of this utility model 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.

[0006] An embodiment of this utility model also provides an electronic device, including the aforementioned ball-type anti-shake motor.

[0007] Compared to existing technologies, this utility model embodiment of the ball bearing image stabilization motor 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 bearing, and the second mover moves in the shaking direction of the motor via a second ball bearing. The movement of the first mover is detected by a first detection unit mounted on a circuit board 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 with different types of detection units: one is a capacitive detection unit, which determines displacement based on changes in the electric field; the other is a magnetic field detection unit, which determines displacement based on changes in the magnetic field. Since the detection conditions of the first and second detection units are different, their detection results do not affect each other, thus ensuring that the detection of focusing displacement and image stabilization displacement do not interfere with each other. This improves the detection accuracy of the magnetic field detection unit, thereby enhancing the overall focusing and image stabilization performance of the motor.

[0008] In addition, the first detection unit is a capacitive detection unit, and the second detection unit is a magnetic field detection unit.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] In addition, the second magnetic field sensor is a Hall sensor or a tunnel magnetoresistive (TMR) sensor.

[0015] 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

[0016] 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.

[0017] Figure 1 This is an exploded structural diagram of the ball bearing anti-shake motor according to an embodiment of this solution;

[0018] Figure 2 This is a schematic diagram of the structure of the first detection unit in the ball bearing anti-shake motor according to an embodiment of this solution;

[0019] Figure 3 This is a schematic diagram of the independent structure of the first detection unit in the ball bearing anti-shake motor according to the embodiment of this solution;

[0020] Figure 4 This is a schematic diagram of the structure of the second detection unit in the ball bearing anti-shake motor according to the embodiment of this solution;

[0021] Figure 5 This is a schematic diagram of the structure of the second detection unit in the ball bearing anti-shake motor according to another embodiment of this solution. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the various embodiments of this utility model 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 utility model 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.

[0023] The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of this utility model. The various embodiments can be combined with or referenced by each other without contradiction.

[0024] Embodiments of this utility model relate to a ball-type anti-shake motor, such as... Figure 1 As shown, the ball-type 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 utilizes the first ball bearing 41 and the base 2 in the focusing direction ( Figure 1 The second moving part 32 undergoes relative displacement with the base 1 in the Z-axis direction (as shown); the second moving part 32 uses the second ball 42 to vibrate in the direction of shaking ( Figure 1 The relative displacement occurs in the X and Y axes (as shown); wherein the shaking direction is perpendicular to the focusing direction; the circuit board 1 is set on the side wall of the base 2; the first detection unit and the second detection unit are both set 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; 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.

[0025] Compared to existing technologies, this utility model embodiment of the ball bearing image stabilization motor 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 bearing, and the second mover moves in the shaking direction of the motor via a second ball bearing. The movement of the first mover is detected by a first detection unit mounted on a circuit board 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 with different types of detection units: one is a capacitive detection unit, which determines displacement based on changes in the electric field; the other is a magnetic field detection unit, which determines displacement based on changes in the magnetic field. Since the detection conditions of the first and second detection units are different, their detection results do not affect each other, thus ensuring that the detection of focusing displacement and image stabilization displacement do not interfere with each other. This improves the detection accuracy of the magnetic field detection unit, thereby enhancing the overall focusing and image stabilization performance of the motor.

[0026] 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.

[0027] 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:

[0028] like Figure 2 As shown, the first detection unit 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.

[0029] 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. The capacitance of each capacitor is calculated using 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. 9 N, i.e., k = 8.987551 × 10 9 N·m² / C; S represents the area (projected area) of the two plates facing each other; d represents the vertical distance between the two plates. 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.

[0030] 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.

[0031] The capacitor structure composed of the floating electrode 51, the transmitting electrode 52, and the two receiving electrodes 53 is as follows: Figure 3 As shown, the size of the floating electrode plate 51 is smaller than the size of the area covered by the transmitting electrode plate 52 and the two receiving electrode plates 53. This ensures that during the process of the first mover driving the floating electrode plate 51 to move in the focusing direction, the floating electrode plate 51 is always within the area covered by the transmitting electrode plate 52 and the two receiving electrode plates 53. That is, during the movement of the floating electrode plate 51, the edge of the floating electrode plate 51 will never exceed the edge of the transmitting electrode plate 52, and the edge of the floating electrode plate 51 will also never exceed the edge of the receiving electrode plate 53.

[0032] In addition, the structure of the second detection unit is as follows: Figure 4 As shown, the second detection unit includes a detection magnet 61 mounted on the second mover 32 and a first magnetic field sensor 62 mounted on a circuit board. The detection magnet 61 and the first magnetic field sensor 62 are positioned opposite each other 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.

[0033] Since the second mover 32 moves in two directions, respectively Figure 4 To ensure the accuracy of displacement detection in the X and Y axes shown, 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, such as... Figure 4 As shown, the detection magnets 61 in the two sets of second detection units are respectively arranged on adjacent sides of the second mover 32, and the first magnetic field sensors in each set of second detection units are respectively arranged at the relative positions of the detection magnets in the set. The number of first magnetic field sensors in each set of second detection units can be multiple. By performing differential processing on the detection results of multiple first magnetic field sensors, the detection accuracy of the first magnetic field sensors is improved.

[0034] In addition, such as Figure 4 As shown, the ball-type anti-shake motor itself includes a drive unit 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 second mover 32, the carrier of the drive magnet 92, can move relative to the base, thus driving the second mover. By changing the current in the drive coil 92, the magnitude of the Lorentz force can be controlled, thereby changing the force on the second mover and controlling the distance of movement.

[0035] 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 configured detection magnet to detect the movement of the second mover, which improves the detection accuracy of the first magnetic field sensor.

[0036] 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 in the drive unit. That is, Figure 5As shown, the second detection unit includes: a second magnetic field sensor 63 mounted on a circuit board; the second magnetic field sensor 63 is positioned opposite to a driving magnet 92; when the second mover 32 moves in the jitter direction, the distance between the driving magnet 92 and the second magnetic field sensor 63 changes accordingly. At this time, the driving magnet serves both to implement the driving function and to cooperate with the second magnetic field sensor to achieve the displacement detection function. 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.

[0037] The second mover moves in at least two directions (e.g., ... Figure 5 As shown in the X-axis and Y-axis directions, corresponding driving magnets are set in two different 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 sensors or tunnel magnetoresistive (TMR) sensors.

[0038] In addition to driving the second mover, a driving unit corresponding to the first mover also needs to be set up. For example... Figure 2 As shown, a focusing magnet 91 corresponding to the first mover 31 is set on the side of the first mover 31, and a focusing coil is set at the position opposite to the focusing magnet 91. The focusing coil is connected to the circuit board. The displacement control of the first mover is achieved by using the focusing magnet 91 and the focusing coil in the same way as the driving method of the second mover described above, and will not be repeated here.

[0039] Furthermore, to ensure that the second mover is not driven by the first mover, the second mover only moves in the direction of shaking and does not undergo displacement in the direction of focusing, such as... Figure 1 As shown, 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, restricting the movement of the second mover 32 in the focusing direction.

[0040] In addition, such as Figure 1 As shown, the ball bearing anti-shake motor also includes a housing 8 covering the periphery of all component structures, which protects the internal structure of the ball bearing anti-shake motor.

[0041] 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.

[0042] Another feasible embodiment of this utility model relates to an electronic device, 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.

[0043] Compared with related technologies, the electronic device provided in this embodiment of the present invention is equipped with the ball-type anti-shake motor provided in the aforementioned embodiment. Therefore, it also has the same technical effects provided in the aforementioned embodiment, which will not be elaborated here.

[0044] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing the present invention, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A ball-type anti-shake motor, characterized in that, include: 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, characterized in that, The first detection unit is a capacitive detection unit, and the second detection unit is a magnetic field detection unit.

3. The ball bearing anti-shake motor according to claim 2, characterized in that, 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 emitting electrode plate remains constant.

4. The ball bearing anti-shake motor according to claim 3, characterized in that, 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, characterized in that, 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 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-type anti-shake motor according to claim 2, characterized in that, 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-type anti-shake motor according to claim 6, characterized in that, 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-type anti-shake motor according to claim 6, characterized in that, 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, characterized in that, Also includes: A pressure cap that fits the second moving part; The pressure cap abuts against the second mover in the focusing direction, restricting the movement of the second mover in the focusing direction.

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

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