CN110708452A - A driving device for realizing automatic focusing and anti-shake of camera - Google Patents

Abstract

The invention relates to a driving device for realizing automatic focusing and anti-shake of a camera. It has a support module and a moving part suitable for lens installation and assembly. The moving part is assembled on the support module through a suspension system, so that the moving part can move along the optical axis of the lens. ; Also include the first and second pairs of drive modules driven by the principle of thermal shrinkage based on the SMA wire, the first pair of drive modules and the second pair of drive modules are driven in opposite directions along the optical axis of the lens; and the first The single-side independent control of the drive module and the second pair of drive modules realizes the angle control of the lens around the X-axis and the Y-axis, and achieves optical anti-shake with adjustable tilt angle. Using the characteristics of thermal shrinkage of the SMA wire to drive the automatic focusing of the lens, and by driving the movement of different sides of the lens, adjust the inclination of the lens around the X-axis and Y-axis, realize the function of optical anti-shake, and improve the performance of the camera. The product structure is lightweight and miniaturized, and the control is simple and precise.

Description

A driving device for realizing automatic focusing and anti-shake of camera

technical field

The invention relates to the technical field of cameras, in particular to the technical field of camera focusing applied to portable electronic devices such as mobile phones or tablet computers.

Background technique

With the development and popularization of portable electronic devices such as mobile phones or tablet computers, the requirements for the accompanying camera functions are also relatively increased. In order to realize the focusing and zooming of the camera, a driving device needs to be arranged in the narrow space of the camera to drive the lens to move along the optical axis. Due to the limited space, the type of drive structure that can be used is also limited. In the prior art cameras, the structure of magnets and coils is mainly used to realize driving, but the structure is still relatively complex, and the volume is difficult to reduce, which cannot meet the requirements of product miniaturization.

At the same time, as miniature autofocus cameras are widely used in mobile phones, automobiles, unmanned aircraft, security monitoring, smart home and other products. The ordinary miniature autofocus camera module is driven by a miniature voice coil motor to move the lens up and down in the direction of the optical axis. When taking pictures, the voice coil motor is driven by the control chip to move, so as to realize the autofocus function. When taking photos or videos, the lens will not be absolutely stable due to human shaking or other reasons, resulting in a certain offset. At this time, the focus of the camera and the amount of incoming light will be affected, thereby affecting the quality of the image obtained by the camera. Generally, this lens deflection occurs in the direction perpendicular to the optical axis, and the autofocus voice coil motor can only drive the lens to move in the direction of the optical axis, so the problem caused by such lens deflection cannot be solved. On the basis of the autofocus voice coil motor, an optical anti-shake actuator is added to drive the lens to move in two directions perpendicular to the optical axis, which can compensate for the above deflection of the lens and help the camera to obtain better image quality. The camera motor is called a micro optical image stabilization camera motor.

The real miniature optical anti-shake camera motor is a closed-loop control system. The lens jitter parameters detected by the gyroscope are fed back to the camera module control chip. The latter calculates the corrected angle or displacement according to the position information provided by the lens position sensor and sends out The command drives the anti-shake actuator to reach the specified position, so as to correct the displacement and deflection of the lens due to jitter, so that better image quality can be obtained when taking pictures or videos.

In the prior art, as with driving the lens to move in the direction of the optical axis, the same method can also be used in two directions perpendicular to the optical axis, that is, a micro voice coil motor is used to realize it. A common miniature voice coil motor uses an energized coil to generate a Loren magnetic force in a magnetic field to drive the lens to move; to achieve optical image stabilization, the lens needs to be driven in at least two directions, which means that multiple coils need to be arranged, which will give the overall structure miniaturization brings certain challenges. For this reason, micro-actuators that use the voice coil motor principle for optical anti-shake generally integrate multiple coils on a circuit board, called FP coils, to solve the size problem of the optical anti-shake actuator. However, the micro-voice coil motor optical anti-shake actuator and the auto-focusing micro-voice coil motor are separated, and the lens is often installed in the auto-focusing micro-voice coil motor, so that the lens is moved in the direction of the vertical optical axis. , which is to make the lens move with the auto-focusing micro-voice coil motor. Therefore, the assembly process of this type of miniature optical anti-shake camera module is more difficult, which also reduces the structural reliability of the entire miniature motor, and at the same time, it is difficult to meet the requirements of product miniaturization.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a driving device for realizing automatic focusing and anti-shake of a camera, which meets the requirements of product miniaturization, obtains better focusing performance of driving the lens to move along the optical axis, and also realizes anti-shake.

To achieve the above object, the present invention adopts the following technical solutions:

A driving device for realizing automatic focusing and anti-shake of a camera, which has a support module and a moving part suitable for lens installation and assembly, the moving part is assembled on the support module through a suspension system, and the suspension system guides the moving part along the optical axis of the lens. and also includes a first pair of drive modules and a second pair of drive modules, the first pair of drive modules are symmetrically arranged on two opposite sides of the moving parts, and the second pair of drive modules are symmetrically arranged on the remaining parts of the moving parts The two opposite sides of the lens; the first pair of drive modules and the second pair of drive modules are driven based on the principle of thermal shrinkage of SMA wires, and the first pair of drive modules has a first drive arm to push the moving parts to move along the optical axis of the lens , the second pair of driving modules has a second driving arm to push the moving parts to move along the optical axis of the lens, and the driving moving parts of the first pair of driving modules and the second pair of driving modules move in opposite directions along the optical axis of the lens; and When the driving module and the second pair of driving modules are independently controlled and driven on one side, the angle control of the lens around the X-axis and/or the Y-axis can be achieved, so as to achieve optical anti-shake with adjustable tilt angle.

The above solution further is that the monomer in the first pair of driving modules includes two first driving arms, a first SMA wire and two first conductive supports, and the first conductive supports are fixed on the support module It is also electrically connected to the control system of the camera. The first conductive support is provided with a first elastic arm that can be stretched and closed. The two first driving arms and the first SMA wire form a movable triangle relationship. The ends are respectively connected to the first elastic arms on the two first conductive supports, one end of the first driving arm is connected to the first elastic arm corresponding to the first conductive support, and the other end of the first driving arm is hingedly connected to the moving part; The monomer in the second pair of driving modules includes two second driving arms, a second SMA wire and two second conductive supports, the second conductive supports are fixed on the support module and are electrically connected to the camera head. In the control system, the second conductive support is provided with a second elastic arm that can be stretched and closed, the two second driving arms and the second SMA wire form a movable triangle relationship, and the two ends of the second SMA wire are respectively connected to the two second elastic arms. The second elastic arm on the two conductive supports, one end of the second driving arm is connected to the second elastic arm corresponding to the second conductive support, and the other end of the second driving arm is hingedly connected to the moving part.

The above solution further is that the suspension system includes an upper spring and a lower spring, and the upper spring and the lower spring are respectively connected between the upper and lower ends of the moving part and the support module; The first flexible part of the upper inner ring is fixedly connected to the upper end of the moving part, and the end of the first flexible part is fixedly connected to the support module; the lower spring includes a lower inner ring and a second flexible part drawn from the outer circumference of the lower inner ring , the lower inner ring is fixedly connected to the lower end of the moving part, and the end of the second flexible part is fixedly connected to the support module.

The above scheme further is that the support module is formed by stacking a bottom plate and an upper seat, and the upper side of the upper seat away from the bottom plate is provided with an upwardly protruding pedestal column, and the pedestal column is adapted to the suspension system and the first pair of drive modules and the second pair of drive modules. installation; a hinge part is arranged on the peripheral side of the moving part, and the hinge part respectively hinges the first drive arm of the first pair of drive modules and the second drive arm of the second pair of drive modules.

In the above solution, the control system of the camera utilizes the resistance of the first SMA wire and/or the second SMA wire as feedback to realize closed-loop control of the movement of the lens.

The above solution further is that the two first driving arms and the first SMA wire form an isosceles triangle relationship, and the two second driving arms and the second SMA wire also form an isosceles triangle relationship, and the first SMA wire and the second SMA wire also form an isosceles triangle relationship. The SMA wire is the base side of the isosceles triangle, and the first SMA wire and the second SMA wire are arranged in an upward and downward dislocation relative to the axial direction of the moving part.

The above solution further is that the two first driving arms are respectively integrally formed with the two first conductive supports; the two second driving arms are respectively integrally formed with the two second conductive supports, and the first elastic arms are integrally formed with the two second conductive supports. The second elastic arm is relatively inverted.

The present invention utilizes the characteristic of SMA (Shape Memory Alloys) wire which is heated and shrinks, and is used to make the driving device of the camera module of the mobile phone or tablet computer, which can drive the lens to move up and down, realize the automatic focusing function of the lens, and utilize the Movement, you can adjust the inclination of the lens around the X-axis and the Y-axis, so that the OIS (optical image stabilization) function can be realized by adjusting the inclination of the lens, and the performance of the camera can be improved. The SMA wire is small in size and effectively simplifies the drive structure, making it meet the requirements of product miniaturization, the product structure is light and miniaturized, and the manufacturing cost is reduced.

Description of drawings:

1 is a schematic structural diagram of a preferred embodiment of the present invention;

2 is a schematic structural diagram of the first pair of driving modules in the embodiment of FIG. 1;

3 is a schematic structural diagram of the second pair of driving modules in the embodiment of FIG. 1;

4 is a schematic structural diagram of the moving parts of the embodiment of FIG. 1;

5 is a schematic structural diagram of the support module of the embodiment of FIG. 1;

6 is a schematic view of the upper spring structure of the embodiment of FIG. 1;

FIG. 7 is a schematic structural diagram of the lower spring of the embodiment of FIG. 1 .

Detailed ways:

The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings, so as to fully understand the purpose, characteristics and effects of the present invention.

It should be noted that in the description of the present invention, the terms "up", "down", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate directions or The terminology of the positional relationship is based on the direction or positional relationship shown in the drawings, which is only for the convenience of description, and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood to limit the present invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

Referring to FIGS. 1 to 7, it is a schematic diagram of a preferred embodiment of the present invention. The present invention relates to a driving device for realizing automatic focusing and anti-shake of a camera, which has a support module 1 and a moving part 2 suitable for lens installation and assembly. Of course, It also includes the inherent control system of the camera device and the corresponding casing (not shown in the figure). The casing covers the moving part 2 and other corresponding components, and has anti-collision and protection functions. The support module 1 is adapted to be installed on a portable electronic device such as a mobile phone or a tablet computer. The moving part 2 is assembled on the support module 1 through a suspension system 3. The suspension system 3 guides the moving part 2 to move along the optical axis of the lens. The moving part 2 An assembly hole is left in the middle of the lens element to meet the requirements of the lens element assembly, so that the moving part 2 moves together with the lens element. And also includes a first pair of drive modules 4 and a second pair of drive modules 5, the first pair of drive modules 4 are symmetrically arranged on two opposite sides of the moving part 2, and the second pair of drive modules 5 are symmetrically arranged on the side. The remaining two opposite sides of the moving part 2; the first pair of driving modules 4 and the second pair of driving modules 5 are driven based on the principle of thermal shrinkage of SMA wires, and the first pair of driving modules 4 has a first driving arm 41 to push The moving part 2 moves along the optical axis of the lens, the second pair of drive modules 5 has a second drive arm 51 to push the moving part 2 to move along the optical axis of the lens, the first pair of drive modules 4 and the second pair of drive modules 5 The driving moving parts 2 move in opposite directions along the optical axis of the lens. In this way, through the thermal contraction of the SMA wire, the corresponding drive arm pushes the moving part 2 to move along the optical axis of the lens and overcomes the reverse force of the suspension system 3, so that the lens can be driven to move up and down, and the automatic focusing function of the lens can be realized. Movements on different sides, such as when the first pair of drive modules 4 and the second pair of drive modules 5 are independently driven and controlled separately (when the two currents are different), two asynchronous drives appear, which can be adjusted The tilt angle of the lens around the X axis and/or the Y axis, so that the OIS (Optical Image Stabilization) function can be achieved by adjusting the lens tilt angle. The suspension system 3 has a corresponding reset capability in operation to cooperate with the first pair of driving modules 4 and the second pair of driving modules 5 .

Referring to FIGS. 1 , 2 and 3 , in this embodiment, the single unit in the first pair of driving modules 4 includes two first driving arms 41 , a first SMA wire 42 and two first conductive branches The seat 43, the first conductive support 43 is fixed on the support module 1 and is electrically connected to the control system of the camera. The first conductive support 43 is provided with a first elastic arm 431 that can be stretched and closed. The two first driving arms 41 and the first SMA wire 42 form a movable triangular relationship. A first elastic arm 431 on the first conductive support 43, one end of the first driving arm 41 is connected to the first elastic arm 431 corresponding to the first conductive support 43, and the other end of the first driving arm 41 is hingedly connected to the moving part 2. The single unit in the second pair of driving modules 5 includes two second driving arms 51 , a second SMA wire 52 and two second conductive supports 53 , and the second conductive supports 53 are fixed on the support module 1 . The control system of the camera is electrically connected to the upper part, the second conductive support 53 is provided with a second elastic arm 531 that can be stretched and closed, and the two second driving arms 51 and the second SMA wire 52 form a movable triangle relationship. Two ends of the two SMA wires 52 are respectively connected to the second elastic arms 531 on the two second conductive supports 53 , and one end of the second driving arms 51 is connected to the second elastic arms 531 corresponding to the second conductive supports 53 . The other end of the arm 51 is hingedly connected to the moving part 2 . SMA wire (such as nickel-titanium memory alloy wire) has a martensitic structure at room temperature. When the temperature rises, the SMA wire will undergo phase transformation, from martensite to austenite, the length becomes shorter, and the resistance becomes smaller; When the temperature decreases, the SMA wire will undergo a phase transformation from austenite to martensite, the length will become longer, and the resistance will become larger, and these two processes can be repeated. During the phase transition, the linearity between temperature and strain of SMA wire is not very good, but its resistance and strain are linear in a certain temperature range. Therefore, the length of the SMA wire can be precisely controlled by controlling the resistance of the SMA wire, and the position and moving distance of the driving device can be calculated according to the resistance of the SMA wire. As a result, the first SMA wire 42 and/or the second SMA wire 52 are energized and heated through the control system, and the SMA wire will shrink, changing the corresponding triangular relationship, so that the corresponding first driving arm 41 and/or the second driving arm 51 The push-up moving part 2 moves along the optical axis of the lens to realize the focusing and zooming of the camera, and the relative stability of the triangle can be used to drive the moving part 2 to move with the lens focusing stably and accurately. In this embodiment, the first pair of driving modules 4 are symmetrically arranged on two opposite sides of the moving part 2 , the second pair of driving modules 5 are symmetrically arranged on the remaining two opposite sides of the moving part 2 , and the first pair The driving moving parts 2 of the driving module 4 and the second pair of driving modules 5 move in opposite directions along the optical axis of the lens. When focusing is achieved, the moving parts 2 can also appear when different driving modules are energized through the control system of the camera. Different side movements can be used to adjust the inclination of the lens around the X-axis and Y-axis, so that the OIS (optical image stabilization) function can be realized by adjusting the inclination of the lens, and the performance of the camera can be improved.

Referring to FIGS. 1 , 2 and 3 , in this embodiment, the two first driving arms 41 and the first SMA wires 42 form an isosceles triangle relationship, and the two second driving arms 51 and the second SMA wires 52 are also in an isosceles triangle relationship. An isosceles triangle relationship is formed, the first SMA wire 42 and the second SMA wire 52 are the bases of the isosceles triangle, and the first SMA wire 42 and the second SMA wire 52 are arranged in an up and down dislocation relative to the axial direction of the moving part 2 and are horizontal, The structure moves more smoothly and the control is more accurate. Further, the two first driving arms 41 are respectively integrally formed with the two first conductive supports 43 , and the first driving arms 41 are connected together by the first elastic arms 431 of the first conductive supports 43 ; The second driving arm 51 is integrally formed with the two second conductive supports 53 respectively. The second driving arm 51 is extended from the second elastic arm 531 of the second conductive support 53. The first elastic arm 431 is connected to the second elastic arm 53. The arm 531 is designed relatively upside down, the structure is optimized, and it is easy to manufacture and assemble. The first conductive support 43 and the second conductive support 53 are connected to the control system circuit of the camera by welding, and the control system also uses the first SMA wire 42 and the second SMA wire. The resistance of the line 52 is used as feedback to realize closed-loop control of the movement of the lens. By comparing the deviation between the real-time resistance value and the target value, the movement deviation of the moving part 2 can be corrected, thereby forming a closed-loop control system with the resistance of the SMA wire as the feedback variable. Get precise control.

As shown in FIGS. 1 to 7 , in this embodiment, the support module 1 is formed by stacking a bottom plate 11 and an upper seat 12 . The upper side of the upper seat 12 away from the bottom plate 11 is provided with an upwardly protruding pillar 121 , and the pillar 121 is adapted to the suspension system 3 and the first pair of drive modules 4 and the second pair of drive modules 5 are installed; the peripheral side of the moving part 2 is provided with a hinge part 21, and the hinge part 21 is respectively hinged to the first pair of the first pair of drive modules 4. The driving arm 41 and the second driving arm 51 of the second pair of driving modules 5 form a driving motion pair. The suspension system 3 includes an upper spring 31 and a lower spring 32 . The upper spring 31 and the lower spring 32 are respectively connected between the upper and lower ends of the moving part 2 and the support module 1 . The upper spring 31 includes an upper inner ring 311 and a first flexible part 312 drawn from the outer circumference of the upper inner ring 311 , the upper inner ring 311 is fixedly connected to the upper end of the moving part 2 , and the end of the first flexible part 312 is fixedly connected to the support module 1; the lower spring 32 includes a lower inner ring 321 and a second flexible portion 322 drawn from the outer circumference of the lower inner ring 321, the lower inner ring 321 is fixedly connected to the lower end of the moving part 2, and the end of the second flexible portion 322 is fixedly connected Support module 1. The suspension system 3 is simple in structure, easy to manufacture and assemble, small in size, and can effectively support the moving part 2 to be suspended on the support module 1 and satisfy the movement of the moving part 2 along the optical axis of the lens; Two pairs of driving modules 5 realize the automatic focusing of the lens.

The present invention utilizes the characteristic of SMA (Shape Memory Alloys) wire which is heated and shrinks, and is used to make the driving device of the camera module of the mobile phone or tablet computer, which can drive the lens to move up and down, realize the automatic focusing function of the lens, and utilize the Movement, you can adjust the inclination of the lens around the X-axis and/or the Y-axis, so that the OIS (optical image stabilization) function can be realized by adjusting the inclination of the lens, and the performance of the camera can be improved. The SMA wire is small in size and effectively simplifies the drive structure, making it meet the requirements of product miniaturization, the product structure is light and miniaturized, and the manufacturing cost is reduced.

Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention should not be limited to the exact same structure and operation as the above description and accompanying drawings. Under the circumstance of the concept and scope of the present invention, many equivalent improvements and changes can be made to the above embodiments through logical analysis, reasoning or limited experiments, but these improvements and changes should all belong to the scope of protection of the present invention.

Claims (7)

1. The utility model provides a realize camera auto focus and anti-shake's drive arrangement which characterized in that: the lens driving device comprises a support module (1) and a moving part (2) suitable for lens installation group, wherein the moving part (2) is assembled on the support module (1) through a suspension system (3), and the suspension system (3) guides the moving part (2) to move along the optical axis of a lens; the device also comprises a first pair of driving modules (4) and a second pair of driving modules (5), wherein the first pair of driving modules (4) are symmetrically arranged on two opposite sides of the moving component (2), and the second pair of driving modules (5) are symmetrically arranged on the remaining two opposite sides of the moving component (2); the first pair of driving modules (4) and the second pair of driving modules (5) are driven based on the principle that the SMA wire is heated to contract, the first pair of driving modules (4) are provided with first driving arms (41) to push the moving part (2) to move along the optical axis of the lens, the second pair of driving modules (5) are provided with second driving arms (51) to push the moving part (2) to move along the optical axis of the lens, and the driving moving parts (2) of the first pair of driving modules (4) and the second pair of driving modules (5) move in opposite directions along the optical axis of the lens; and the single-side independent control driving of the first pair of driving modules (4) and the second pair of driving modules (5) realizes the angle control of the lens around the X axis and/or the Y axis, thereby achieving the inclination angle adjustment type optical anti-shake effect.

2. The driving device for realizing automatic focusing and anti-shaking of the camera according to claim 1, wherein: the single body of the first pair of driving modules (4) comprises two first driving arms (41), a first SMA wire (42) and two first conductive supports (43), the first conductive supports (43) are fixed on the support module (1) and electrically connected with a control system of the camera, the first conductive supports (43) are provided with first elastic arms (431) capable of opening and closing, the two first driving arms (41) and the first SMA wire (42) form a movable triangular relation, two ends of the first SMA wire (42) are respectively connected with the first elastic arms (431) on the two first conductive supports (43), one end of each first driving arm (41) is connected with the corresponding first elastic arm (431) of the first conductive support (43), and the other end of each first driving arm (41) is hinged with the moving part (2); the single body of the second pair of driving modules (5) comprises two second driving arms (51), a second SMA wire (52) and two second conductive supports (53), the second conductive supports (53) are fixed on the support module (1) and electrically connected with a control system of the camera, second elastic arms (531) capable of opening and closing are arranged on the second conductive supports (53), the two second driving arms (51) and the second SMA wire (52) form a movable triangular relation, two ends of the second SMA wire (52) are respectively connected with the second elastic arms (531) on the two second conductive supports (53), one end of each second driving arm (51) is connected with the second elastic arm (531) corresponding to the second conductive support (53), and the other end of each second driving arm (51) is hinged with the moving part (2).

3. The driving device for realizing automatic focusing and anti-shaking of the camera according to claim 1, wherein: the suspension system (3) comprises an upper spring (31) and a lower spring (32), and the upper spring (31) and the lower spring (32) are respectively connected between the upper end and the lower end of the moving part (2) and the support module (1); the upper spring (31) comprises an upper inner ring (311) and a first flexible part (312) led out from the periphery of the upper inner ring (311), the upper inner ring (311) is fixedly connected with the upper end of the moving component (2), and the tail end of the first flexible part (312) is fixedly connected with the support module (1); the lower spring (32) comprises a lower inner ring (321) and a second flexible part (322) led out from the periphery of the lower inner ring (321), the lower inner ring (321) is fixedly connected with the lower end of the moving component (2), and the tail end of the second flexible part (322) is fixedly connected with the support module (1).

4. The driving device for realizing automatic focusing and anti-shaking of the camera according to claim 1, 2 or 3, wherein: the supporting module (1) is formed by overlapping a bottom plate (11) and an upper seat (12), an upward convex table column (121) is arranged on the upper side, deviating from the bottom plate (11), of the upper seat (12), and the table column (121) is matched with the suspension system (3) and is installed with the first pair of driving modules (4) and the second pair of driving modules (5); the side of the moving component (2) is provided with a hinge part (21), and the hinge part (21) is respectively hinged with a first driving arm (41) of the first pair of driving modules (4) and a second driving arm (51) of the second pair of driving modules (5).

5. The driving device for realizing automatic focusing and anti-shaking of the camera according to claim 2, wherein: the control system of the camera realizes closed-loop control on the movement of the lens by using the resistance of the first SMA wire (42) and/or the second SMA wire (52) as feedback.

6. The driving device for realizing automatic focusing and anti-shaking of the camera according to claim 2, wherein: the two first driving arms (41) and the first SMA wire (42) form an isosceles triangle relationship, the two second driving arms (51) and the second SMA wire (52) also form the isosceles triangle relationship, the first SMA wire (42) and the second SMA wire (52) are the bottom sides of the isosceles triangle, and the first SMA wire (42) and the second SMA wire (52) are arranged in a vertically staggered mode relative to the axial direction of the moving part (2).

7. The driving device for realizing automatic focusing and anti-shaking of the camera according to claim 2 or 6, wherein: the two first driving arms (41) are respectively integrally formed with the two first conductive supports (43); the two second driving arms (51) are respectively and integrally formed with the two second conductive supports (53), and the first elastic arm (431) and the second elastic arm (531) are designed to be inverted relatively.

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