CN211603672U - Focusing driving device, camera module and electronic equipment comprising same - Google Patents

Abstract

The present disclosure relates to the field of electronic devices, and more particularly, to a focus driving device and an electronic device including the same. The device comprises: a mover member for carrying the optical lens; a stator component; at least one focusing elastic part, one end of which is connected with the stator part and the other end of which is connected with the rotor part, so that the rotor part is suspended relative to the stator part; the optical lens can move along the optical axis direction of the optical lens under the driving of the rotor component; the at least one focusing elastic component is made of shape memory alloy.

Description

Focusing driving device, camera module and electronic equipment comprising same

Technical Field

The present disclosure relates to the field of electronic devices, and more particularly, to a focus driving device and an electronic device including the same.

Background

With the development of miniaturization and function diversification of various electronic products, many electronic products have a camera function, such as mobile phones and tablet computers with the camera function. In application scenes such as photographing and video, it is often necessary to change the focal position of a camera or a lens to achieve Auto Focus (AF) and Optical Image Stabilization (OIS) for improving the imaging quality.

The automatic focusing is realized by utilizing the light reflection principle of a shot object, imaging and receiving light reflected by the shot object on an image sensor after passing through a lens, obtaining the object distance of the shot object through computer processing, and then automatically moving the lens according to the object distance to finish focusing.

Optical anti-shake refers to the fact that in an imaging instrument such as a camera, the shake phenomenon of the instrument occurring in the process of capturing an optical signal is avoided or reduced through the arrangement of optical components such as a lens, so that the imaging quality is improved. It is common practice to perform shake detection by a gyroscope and then translate or rotate the entire lens in the opposite direction by an OIS motor to compensate for image blur during exposure due to shake of the imaging equipment.

There are several methods for achieving auto-focus and optical anti-shake, among which voice coil motors are most widely used. A Voice Coil Motor (VCM), also known as a voice coil motor, is one of the voice coil motors in electronics. Because the principle is similar to that of a loudspeaker, the voice coil motor has the characteristics of high frequency response and high precision. The main principle of the voice coil motor is that in a permanent magnetic field, the extension position of a spring piece is controlled by changing the direct current of a coil in the motor, so that the spring piece is driven to move up and down. The mobile phone camera widely uses the voice coil motor to realize the automatic focusing function, and the position of the lens can be adjusted through the voice coil motor to present clear images.

For the optical anti-shake function, the micro movement can be detected through a gyroscope in the lens, then a signal is transmitted to a microprocessor, the microprocessor immediately calculates the displacement required to be compensated, and then compensation is carried out through a compensation lens group according to the shake direction and the displacement of the lens; thereby effectively overcoming the image blur caused by the vibration of the camera. The anti-shake technology has high requirements on lens design and manufacture, and the cost is relatively high. The most common of these is the suspended wire configuration.

The spring plate and the suspension in the suspension structure are among the most vulnerable parts of the voice coil motor. Therefore, how to prolong the durability of the spring plate and the suspension wire is the key for improving the reliability of the electronic product.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a focusing driving device, which has good impact resistance and can improve the reliability of the shooting function of electronic equipment.

In a first aspect, there is provided a focus driving apparatus for an optical lens, the apparatus comprising: a mover member for carrying the optical lens; a stator component; at least one focusing elastic part, one end of which is connected with the stator part and the other end of which is connected with the rotor part, so that the rotor part is suspended relative to the stator part; the optical lens can move along the optical axis direction of the optical lens under the driving of the rotor component; the at least one focusing elastic component is made of shape memory alloy.

The focusing elastic part in the focusing driving device provided by the embodiment of the application is prepared from the shape memory alloy, and can bear larger impact, so that the device has good impact resistance.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the apparatus further includes an elastic support component, and the elastic support component is made of a shape memory alloy.

In this implementation, the elastic support member is also made of a shape memory alloy, and can bear large impact, thereby further improving the impact resistance of the focusing drive device.

With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the elastic supporting component includes a vertical elastic sheet; the upper end of the vertical elastic sheet is connected with the lens support, and the lower end of the vertical elastic sheet is fixed on the rotor component; the optical lens is fixed on the lens bracket; the at least one focusing elastic member comprises an upper elastic member and a lower elastic member; the upper end of the rotor part is connected with the upper elastic part, and the lower end of the rotor part is connected with the lower elastic part; the upper elastic part is mounted on the stator part to suspend the mover part relative to the stator part.

In this implementation, the mover part is suspended on the stator part, so that the lens can be driven by the mover part to move along the optical axis direction.

With reference to the second possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, the mover member is located inside the stator member.

With reference to the second possible implementation manner of the first aspect, in a fourth possible implementation manner of the first aspect, the device includes a plurality of mover members, where the mover members are uniformly distributed on a first plane along an angular direction with respect to the optical axis, and the first plane is perpendicular to the optical axis; the elastic supporting part comprises a plurality of vertical elastic sheets; the plurality of rotor parts correspond to the plurality of vertical elastic sheets one by one; the optical lens can realize lens deflection under the driving of at least one of the plurality of rotor parts so as to realize optical anti-shake.

In this implementation, optical anti-shake may be achieved through lens deflection.

With reference to the first possible implementation manner of the first aspect, in a fifth possible implementation manner of the first aspect, the at least one focusing elastic member includes an upper elastic member and a lower elastic member; one end of the stator component is connected with the upper elastic component, and the other end of the stator component is connected with the lower elastic component; one end of the rotor part is connected with an upper elastic part, and the other end of the rotor part is connected with a lower elastic part, so that the rotor part is suspended relative to the stator part; the elastic supporting part is a suspension wire, the upper end of the suspension wire is connected with the upper elastic part, and the lower end of the suspension wire is fixed on the base, so that the optical lens is suspended relative to the base, and the optical lens can move in parallel on a first plane under the drive of the stator part, wherein the first plane is vertical to the direction of the optical axis.

In this implementation, the optical lens can be driven by the stator component to move in parallel on the first plane perpendicular to the optical axis direction, so that optical anti-shake can be realized.

With reference to the fifth possible implementation manner of the first aspect, in a sixth possible implementation manner of the first aspect, the mover member is located inside the stator member.

With reference to the first aspect, in a seventh possible implementation manner of the first aspect, the shape memory alloy is any one of the following:

Ni-Ti-based alloy, Cu-based alloy, Fe-based alloy, Ag-based alloy.

In this implementation, the spring plate is made of a specific shape memory alloy so that the spring plate can withstand a large impact.

With reference to the seventh possible implementation manner of the first aspect, in an eighth possible implementation manner of the first aspect, the Ni — Ti based alloy is any one of:

NiTi alloy, NiTiCu alloy, NiTiPd alloy, NiTiFe alloy, NiTiNb alloy, NiTiGa alloy and NiTiCo alloy.

In this implementation, the spring plate is made of a specific Ni-Ti based alloy so that the spring plate can withstand a large impact.

With reference to the eighth possible implementation manner of the first aspect, in a ninth possible implementation manner of the first aspect, the atomic percentage of the Ni element in the NiTi alloy is 50.6% to 51.3%.

In the implementation mode, the NiTi alloy with the Ni element atomic percent of 50.6% -51.3% is used for preparing the elastic sheet, so that the elastic sheet can be in an austenite phase at the use environment temperature of the electronic equipment, can be converted into a martensite phase under the condition of bearing large impact, and can be automatically recovered into the austenite phase from the martensite phase under the condition of no external impact.

With reference to the seventh possible implementation manner of the first aspect, in a tenth possible implementation manner of the first aspect, the Cu-based alloy includes any one of:

CuZn alloy, CuSn alloy, CuZnAl alloy, CuZnSi alloy, CuAlNi alloy, CuAlBe alloy, CuAlMn alloy.

In this implementation, the spring plate is made of a specific Cu-based alloy so that the spring plate can withstand a large impact.

With reference to the seventh possible implementation manner of the first aspect, in an eleventh possible implementation manner of the first aspect, the Fe-based alloy includes any one of:

FePt alloy, FeNiNb alloy, FeMnSi alloy, FeNiC alloy, and FeNiCoTi alloy.

In this implementation, the spring plate is made of a specific Fe-based alloy so that the spring plate can withstand a large impact.

With reference to the seventh possible implementation manner of the first aspect, in a twelfth possible implementation manner of the first aspect, the Ag-based alloy includes an AgCd alloy.

In this implementation, the spring plate is prepared from a specific AgCd alloy, so that the spring plate can bear large impact.

With reference to the first aspect, in a thirteenth possible implementation manner of the first aspect, in a state where the at least one focusing elastic member is not impacted, the shape memory alloy is in an austenite phase.

In this implementation, the spring plate is in an austenite phase in a non-impacted state, and can be transformed into a martensite phase when being subjected to a large impact, so that the spring plate can bear the large impact; and after the impact is finished, the martensite phase can be recovered to the austenite phase so as to be prepared for the impact again.

With reference to the first aspect, in a fourteenth possible implementation manner of the first aspect, the apparatus is a voice coil motor.

In a second aspect, a camera module is provided, which includes the device of the first aspect and an optical lens.

In a third aspect, an electronic device is provided, which includes the apparatus of the first aspect and an optical lens.

The focusing driving device provided by the embodiment of the application has good impact resistance, and the reliability of the shooting function of the electronic equipment can be improved.

Drawings

Fig. 1 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure;

fig. 2 is a schematic plan view of a focusing driving apparatus according to an embodiment of the present disclosure;

FIG. 3 is a schematic plan view of another focusing driving apparatus according to an embodiment of the present disclosure;

fig. 4a is a schematic overall structure diagram of another focusing driving device provided in the embodiment of the present application;

FIG. 4b is an exploded view of the focus drive apparatus shown in FIG. 4 a;

FIG. 4c is a schematic view of the focusing and anti-shake operation of the focusing driving device shown in FIG. 4 a;

fig. 5a is a schematic overall structure diagram of another focusing driving device provided in the embodiment of the present application;

FIG. 5b is an exploded view of the focus drive apparatus shown in FIG. 5 a;

FIG. 5c is a schematic view of the focusing and anti-shake operation of the focusing driving device shown in FIG. 5 a;

FIG. 6 is a schematic diagram showing the relationship between the Ni content and the martensite start temperature in the NiTi alloy;

FIG. 7 is a graph showing the stress-strain curves of the memory metal and the high strength metal;

FIG. 8 is a graph showing the comparison of the impact resistance of the memory metal, the common metal and the high strength metal;

fig. 9 is a schematic view of a vertical elastic sheet for a focusing driving device according to an embodiment of the present disclosure;

fig. 10 is a schematic view illustrating impact simulation performed on the spring plate shown in fig. 9;

fig. 11 is a comparison diagram of the impact simulation results of the elastic sheet made of the high-strength metal and the elastic sheet made of the memory metal.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments.

In the description of the present specification, "a plurality" means two or more unless otherwise specified.

Reference throughout this specification to "one embodiment" or "some embodiments," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise.

Wherein in the description of the present specification, "/" indicates a meaning, for example, a/B may indicate a or B; "and/or" herein is merely an association describing an associated object, and means that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality" means two or more than two.

In the description of the present specification, the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless expressly specified otherwise.

In this document, "up" refers to an object side direction of the optical lens, and "down" refers to an image side direction of the optical lens.

The focusing driving device provided by the embodiment of the application can be applied to the electronic device 100. The electronic device 100 may be a portable electronic device such as a mobile phone, a tablet computer, a digital camera, a Personal Digital Assistant (PDA), a wearable device, and a laptop computer (laptop). The portable electronic device may also be other portable electronic devices such as laptop computers (laptop) with touch sensitive surfaces (e.g., touch panels), etc. It should also be understood that in some other embodiments of the present application, the electronic device 100 may not be a portable electronic device, but rather a desktop computer having a touch-sensitive surface (e.g., a touch panel). The embodiment of the present application does not specifically limit the type of the electronic device 100.

Fig. 1 shows a schematic structural diagram of an electronic device 100.

The electronic device 100 may include a processor 110, an external memory interface 120, an internal memory 121, a Universal Serial Bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a key 190, a motor 191, an indicator 192, a camera 193, a display screen 194, a Subscriber Identification Module (SIM) card interface 195, and the like. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity light sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, and the like.

It is to be understood that the illustrated structure of the embodiment of the present invention does not limit the electronic device 100. In other embodiments of the present application, electronic device 100 may include more or fewer components than shown, or some components may be combined, some components may be split, or a different arrangement of components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

Processor 110 may include one or more processing units, such as: the processor 110 may include an Application Processor (AP), a modem processor, a Graphics Processor (GPU), an Image Signal Processor (ISP), a controller, a video codec, a Digital Signal Processor (DSP), a baseband processor, and/or a neural-Network Processing Unit (NPU), etc. The different processing units may be separate devices or may be integrated into one or more processors.

The electronic device 100 may implement a shooting function through the ISP, the camera 193, the video codec, the GPU, the display 194, the application processor, and the like.

The ISP is used to process the data fed back by the camera 193. For example, when a photo is taken, the shutter is opened, light is transmitted to the camera photosensitive element through the lens, the optical signal is converted into an electrical signal, and the camera photosensitive element transmits the electrical signal to the ISP for processing and converting into an image visible to naked eyes. The ISP can also carry out algorithm optimization on the noise, brightness and skin color of the image. The ISP can also optimize parameters such as exposure, color temperature and the like of a shooting scene. In some embodiments, the ISP may be provided in camera 193.

The camera 193 is used to capture still images or video. The object generates an optical image through the lens and projects the optical image to the photosensitive element. The photosensitive element may be a Charge Coupled Device (CCD) or a complementary metal-oxide-semiconductor (CMOS) phototransistor. The light sensing element converts the optical signal into an electrical signal, which is then passed to the ISP where it is converted into a digital image signal. And the ISP outputs the digital image signal to the DSP for processing. The DSP converts the digital image signal into image signal in standard RGB, YUV and other formats. In some embodiments, the electronic device 100 may include 1 or N cameras 193, N being a positive integer greater than 1.

The camera 193 may include a focus driving device, and the movable lens performs focusing. In some embodiments, the focus driving device may be a voice coil motor.

In some embodiments, referring to fig. 2, the focus driving device in the camera 193 may include an upper spring, a lower spring, a stator component, and a mover component (not shown). One end of the upper elastic sheet is connected with the stator part, the other end of the upper elastic sheet is connected with the rotor part, one end of the lower elastic sheet is connected with the stator part, and the other end of the lower elastic sheet is connected with the rotor part; so that the rotor part can be suspended on the stator part through the upper spring plate and the lower spring plate. The suspension of the mover element on the stator element may also be referred to as the suspension of the mover element relative to the stator element. The mover component is used for bearing the lens. The lens can move up and down along the optical axis direction of the optical lens under the driving of the rotor component so as to realize focusing. In one example, the mover member may be suspended on the stator member by 4 upper spring plates and 4 spring plates. The upper spring plate and the lower spring plate can be collectively called as a focusing elastic component, and can also be collectively called as a spring plate.

In some examples of these embodiments, referring to fig. 3, the focus drive may further include an Optical Image Stabilization (OIS) mover component and a suspension wire. The OIS mover member is for carrying the stator member. The OIS rotor component can be supported and fixed on the base through the suspension wires, so that the lens can move in parallel on the first plane under the driving of the OIS rotor component. In one example, the OIS mover member may be supported and secured to the base by 4 suspension wires.

In some embodiments, referring to fig. 4a and 4b, the focus driving apparatus in the camera 193 may include a lens holder 410, an upper spring 420, a vertical spring 430, a mover member 440, a lower spring 450, a stator member 460, a base 470, and a housing 480. The lens holder 410 is used to carry a lens. The lens holder 410 may be mounted on the upper end of the vertical elastic piece 430. The lower end of the vertical elastic piece 430 may be fixed (e.g., fixed by bonding) on the mover member 440, so that the lens holder 410 may be carried on the mover member 440 by the vertical elastic piece 430, so that the lens may move in the optical axis direction of the optical lens under the driving of the mover member 440. In one example, the lens holder 410 may be mounted on the 4 mover members 440 through the 4 vertical spring pieces 430. The vertical spring plate 430, the upper spring plate 420, and the lower spring plate 450 may be collectively referred to as spring plates. The upper spring plate 420 and the lower spring plate 450 may be collectively referred to as a focusing elastic member.

The upper end of the mover member 440 may be mounted on the stator member 460 through the upper spring 420 (such that the mover member 440 may be suspended with respect to the stator member 460, i.e., such that the mover member is suspended on the stator member 460 through the upper spring 420), and the lower end of the mover member 440 may be mounted on the base 470 through the lower spring 450, such that the lens may be movable in the up-down direction (i.e., the optical axis direction of the lens).

In some examples of these embodiments, as shown in fig. 4a, the focus driving apparatus may include a plurality of (e.g., 4) mover members 440, and the plurality of mover members 440 may be evenly distributed on the first plane in an angular direction with respect to the optical axis of the optical lens. The first plane is a plane perpendicular to an optical axis of the optical lens. The upper ends of the plurality of mover members 440 may be mounted on the stator member 460 through the plurality of upper spring pieces 420, and the lower ends of the mover members 440 may be mounted on the base 470 through the lower spring pieces 420. In one example, the upper end of the mover member 440 and the upper spring 420 may be coupled by adhesion. In one example, the lower end lower spring 450 of the mover member 440 may be coupled by bonding.

In another example of these examples, each mover member 440 may be internally provided with a coil, and an axis of the coil of any mover member 440 is perpendicular to the optical axis. The stator component 460 may include a plurality of magnets.

In one specific implementation, as shown in FIG. 4b, the number of the mover members 440 may be four, and the stator member 460 may include eight magnets, where there are two magnets for each mover member 440. Referring to fig. 4c, taking the two magnets corresponding to any one of the mover members 440 as an example, the two magnets are a magnet a and a magnet B, which have opposite polarities and are arranged vertically (in the optical axis direction of the lens). As shown in FIG. 4c, the upper and lower sides of the same coil correspond to one of the two magnets, respectively. When the coils are electrified, the current directions of the upper side and the lower side in the same coil are opposite, and combined with the magnet A and the magnet B, ampere force with the same force direction can be generated, so that the lens can be driven to move along the optical axis direction of the lens, or the lens is driven to deflect.

When focusing is needed, the coils of the mover parts 440 are all energized to generate an ampere force with the stator part 460, so that the mover parts 440 move along the optical axis direction of the lens, thereby realizing focusing.

When optical anti-shake is required, the coils of different mover members 440 may be differently controlled, such as whether to be energized or not, and the direction of the current to be energized, so that one or both of the mover members 440 adjacent to each other move up or down in the optical axis direction, and the opposite one or both of the mover members do not move or move in the opposite direction, thereby deflecting the angle of the lens, thereby achieving optical anti-shake. For example, the coils of one mover member 440 may be energized, while the coils of the other mover member 440 are not energized. The energized coil and the stator part 460 act to generate an ampere force, and the mover part 440 where the coil is located is pushed to move along the optical axis direction. The mover member 440 where the coil is not energized does not move in the optical axis direction. Therefore, the angle of the lens can be deflected, and optical anti-shake is realized.

In one example of these examples, mover member 440 may be a magnet. A plurality of independent coils may be disposed inside the stator part 460. The axis of any coil of the plurality of independent coils is perpendicular to the optical axis. The plurality of independent coils correspond to the plurality of mover members 440, respectively.

In one specific implementation, as shown in fig. 4b, the number of the mover members 440 may be four, wherein each mover member 440 includes two magnets with opposite polarities and arranged up and down (in the optical axis direction). The two magnets correspond to the upper and lower (along the optical axis) sides of the coil, respectively. When the coils are electrified, the directions of currents on the upper side and the lower side of the same coil are opposite, and the two magnets with opposite polarities are combined to generate ampere force with the same force direction, so that the lens can be driven to move along the direction of an optical axis or deflect.

When focusing is needed, the plurality of coils in the stator part 460 are all energized to act on the corresponding mover parts 440 to generate ampere force, so as to push the mover parts 440 to move along the optical axis direction, thereby realizing focusing.

When optical anti-shake is required, different energization controls may be performed on different coils in the stator part 460, such as whether to energize or not, the direction of the energized current, and the like, so that the mover part 440 on one side or two adjacent sides moves up or down along the optical axis direction, and the opposite side or two opposite sides do not move or move in the opposite direction, so as to deflect the angle of the lens, thereby achieving optical anti-shake. For example, one side of the coils in the stator component 460 may be energized and the other side of the coils may be de-energized. The energized coil acts on the corresponding mover member 440 to generate an ampere force, and pushes the mover member 440 to move in the optical axis direction. The mover member 440 corresponding to the coil that is not energized does not move in the optical axis direction. Therefore, the angle of the lens can be deflected, and optical anti-shake is realized.

In some embodiments, referring to fig. 5a and 5b, the focus driving device in the camera 193 may include an upper spring 510, a stator part 520, a magnet 530, a mover part 540, a suspension wire 550, and a lower spring 560. The upper spring 510 and the lower spring 560 may be collectively referred to as a focusing elastic member, or may be collectively referred to as a spring.

The mover part 540 may be nested inside the stator part 520. The magnet 530 is located between the mover member 540 and the stator member 520, and is mounted on the stator member 520.

The upper end of the mover part 540 and the upper end of the stator part 520 may be connected to the upper spring 510 by means of bonding, etc., respectively, and the lower end of the mover part 540 and the lower end of the stator part 520 may be connected to the lower spring 560 by means of bonding, etc., respectively, so that the mover part 530 may be suspended on the stator part 520 by means of the upper spring 510 and the lower spring 560. The suspension of the mover member 530 to the stator member 520 may also be referred to as the suspension of the mover member 530 to the stator member 520. The upper elastic sheet 510 has a hollow structure, so that a lens can be accommodated and fixed. The mover member 540 is also a hollow structure to receive and fix the lens. The lower spring 560 is a hollow structure to accommodate and fix the lens to move along the optical axis of the lens. The base 570 is also hollow to allow the lens to move in the direction of the optical axis of the lens.

The mover member 540 may be internally provided with a focusing coil having an axis parallel to the optical axis. When focusing is required, the focusing coil inside the mover member 540 is energized to act on the magnet 530 to generate an ampere force, which drives the mover member 540 to move along the optical axis direction, thereby achieving focusing. Specifically, referring to fig. 5c, when the focusing coil is powered on, the magnet 530 may be combined to generate an ampere force along the optical axis direction, so as to drive the mover component 540 to move along the optical axis direction of the lens.

The upper spring 510 is mounted on the upper end of the suspension wire 550, and the lower end of the suspension wire 550 is fixed to the base 570 to support the lens away from the base 570, so that the lens is movable in any direction of the first plane. The first plane is perpendicular to the optical axis direction.

An OIS coil may be provided inside the base 570 with its axis parallel to the optical axis direction. When the OIS coil is energized, it may act on the magnet 530 to generate an ampere force, which pushes the stator component 520 to move in parallel on the first plane, thereby implementing optical anti-shake.

In one example, referring to FIG. 5c, the settable focus driving device may comprise four magnets 530. Four OIS coils may be provided inside the base station 570. The four OIS coils correspond to the four magnets 530 one to one. As shown in fig. 5c, OIS coil a and OIS coil B of the four OIS coils are taken as an example. The OIS coil a is energized to generate a resultant force in a first direction in combination with its corresponding magnet 530. The OIS coil B is energized to generate a resultant force in a first direction in combination with its corresponding magnet 530. The first direction is a direction on a first plane. So that the lens can be moved in parallel on the first plane.

Each of the four OIS coils is independent of the other and may be energized simultaneously, or any two or three of them may be energized simultaneously, or any one of them may be energized simultaneously.

The electronic device 100 can realize focusing and optical anti-shake during shooting by using the focusing driving device provided by the embodiment of the application, and improve the image definition of the shot picture or video.

It is desired by users to improve the image clarity of the shot pictures or videos, and the reliability of the shooting function of the electronic device is also desired by users. Before the electronic device leaves a factory, a reliability test needs to be performed on a shooting function of the electronic device. The method mainly comprises the test items of dropping, rolling, random vibration and the like.

In the tests, it was found that the spring plate and the suspension wire in the focus drive are one of the more vulnerable components. Particularly, for the voice coil motor, as the requirements for the load and the stroke of the motor are higher and higher, and the structures of the elastic sheet and the suspension wire are more and more diversified, the reliability problem of the elastic sheet and the suspension wire has become an important bottleneck in the development of the voice coil motor.

The idea of improving the reliability of the spring plate and the suspension wire can be structure optimization and process optimization. Both of these approaches consume a lot of manpower, material resources, and time, and have limited effectiveness.

The application designer carries out a large amount of experimental research to look for suitable materials, so as to improve the shock resistance of the elastic sheet (such as an upper elastic sheet, a lower elastic sheet and a vertical elastic sheet) and the suspension wire in the focusing driving device, prolong the service life of the focusing driving device and improve the reliability of the shooting function of the electronic equipment.

Through a large number of experimental researches, and tests on a plurality of focusing driving devices comprising elastic sheets and/or suspension wires made of different materials by adopting the reliability test items in the experiments, it is found that when the elastic sheets and/or suspension wires made of Shape Memory Alloy (SMA) are not easy to lose efficacy, the SMA has stronger shock resistance, the service life of the focusing driving device can be prolonged, and the reliability of the shooting function of the electronic equipment can be improved.

Next, the shape memory alloy will be described.

Shape memory alloys, also known as memory metals, are characterized by an austenite phase at higher temperatures and a martensite phase at lower temperatures. In most shape memory alloy materials, the austenite phase exhibits a superlattice structure with a sublattice of body-centered cubic. Because the crystal lattice of the austenite phase has high crystal symmetry, the austenite phase has many symmetrically related transformed martensite phases. In the case of copper, zinc and aluminum, the austenite phase can be transformed into twelve different martensite phases. Both temperature and mechanical force can trigger a phase transition between the austenite and martensite phases, and the application of thermal or mechanical stimuli shape changes are closely related to Shape Memory Effect (SME) and Super Elasticity (SE), respectively. In the case of a mechanical force-triggered transformation of austenite phase into martensite phase, the martensite phase is stress-induced.

In the embodiments of the present application, the spring plate and/or the suspension wire in the focus driving apparatus are made of a memory metal and are manufactured to be in an austenite phase under normal operating conditions of the electronic device (e.g., -20 ℃ -80 ℃ and the like). The elastic sheet can be made by smelting memory metal raw materials, and then forging and rolling. The suspension wire can be produced by melting a memory metal material, and then forging, rolling, and drawing.

In the normal working temperature range, when the elastic sheet and/or the suspension wire receives the action of external load, large deformation can be generated through the phase transformation of austenite phase to martensite phase, the local deformation can reach 7 percent, and the elastic sheet and/or the suspension wire can return to the original shape through reverse phase transformation without generating any residual deformation after the external force is removed.

Any one or any combination of a plurality of upper spring pieces, lower spring pieces, suspension wires and vertical spring pieces in the focusing driving device provided by the embodiment of the application can be prepared by adopting the memory metal shown in the table 1.

TABLE 1

In the case of NiTi, the memory metal, the atomic percentage of the Ni element therein determines the martensite start (Ms) temperature. Referring to FIG. 6 (see https:// en. wikipedia. org/wiki/Nickel. titanium), the Ms temperature can be as low as-several tens of degrees when the atomic percent of Ni element in the alloy is around 51%. Therefore, in order to provide a focus actuator with good reliability even at a low temperature, NiTi having an atomic percentage of Ni element of about 51% may be used to prepare the spring plate and/or suspension wire of the focus actuator. The atomic percentage of an element in an alloy refers to the number of atoms of that element in every 100 atoms of the alloy, which may be referred to as at%.

In some embodiments, the atomic percent of the Ni element in the NiTi alloy used to make the spring and/or suspension wire is 50.6% -51.3%. In one example, the atomic percent of the Ni element is 50.6%. In one example, the atomic percent of the Ni element is 50.7%. In one example, the atomic percent of the Ni element is 50.8%. In one example, the atomic percent of the Ni element is 50.9%. In one example, the atomic percent of the Ni element is 51.0%. In one example, the atomic percent of the Ni element is 51.1%. In one example, the atomic percent of the Ni element is 51.2%. In one example, the atomic percent of the Ni element is 51.3%.

In some embodiments, the spring and/or the suspension wire in the focusing driving device in the embodiments of the present application may be made of a memory metal, and the memory metal may specifically be any one or a combination of more of the memory metals shown in table 1.

In one illustrative example, the spring plate and the suspension wire of the focus drive apparatus may be made of the same memory metal. For example, the alloy may be made of a NiTi-based alloy, and more specifically, the NiTi-based alloy for making the spring and the suspension may be NiTi, NiTiCu, NiTiPd, NiTiFe, NiTiNb, NiTiGa, or NiTiCo. For another example, both can be made from a Cu-based alloy. And further, for example, can be produced from an Fe-based alloy. And further, for example, can be produced from an Ag-based alloy. Specific materials of the Cu-based alloy, the Fe-based alloy, and the Ag-based alloy can be as shown in table 1.

In one illustrative example, the spring and suspension wires of the focus drive may be made of different memory metals. For example, the spring plate may be made of a NiTi-based alloy, and the suspension wire may be made of a Cu-based alloy. For another example, the spring plate may be made of an Fe-based alloy, and the suspension wire may be made of an Ag-based alloy. And so on. This is not further enumerated here.

In one illustrative example, the upper spring plate and the lower spring plate in the focus driving apparatus may be made of the same memory metal. For example, they can be prepared from NiTi, NiTiCu, CuZn, FePt, AgCd, and the like. This is not further enumerated here.

In one illustrative example, the upper spring plate and the lower spring plate in the focus driving device may be made of different memory metals. For example, the upper spring plate may be made of NiTi and the lower spring plate may be made of NiTiCu. For another example, the upper spring plate may be made of CuZn and the lower spring plate may be made of FePt. For another example, the upper spring plate may be made of NiTiCu and the lower spring plate may be made of AgCd. And so on. This is not further enumerated here.

In an illustrative example, if the focus driving apparatus is the apparatus shown in fig. 4a, the upper spring, the lower spring and the vertical spring may be made of the same memory metal. For example, they can be prepared from NiTi, NiTiCu, CuZn, FePt, AgCd, and the like. This is not further enumerated here.

In an illustrative example, if the focus driving apparatus is the apparatus shown in fig. 4a, the upper spring, the lower spring and the vertical spring may be made of different memory metals. For example, the upper spring plate and the lower spring plate can be made of NiTi, and the vertical spring plate can be made of NiTiCu. For another example, the upper spring plate and the lower spring plate may be made of CuZn, and the vertical spring plate may be made of FePt. For another example, the upper spring plate and the lower spring plate may be made of NiTiCu, and the vertical spring plate may be made of AgCd. For another example, the upper spring plate may be made of NiTi, the lower spring plate may be made of FeNiNb, and the vertical spring plate may be made of NiTiCu. For another example, the upper spring may be made of NiTiPd, the lower spring may be made of CuZnAl, and the vertical spring may be made of FeMnSi. And so on. This is not further enumerated.

The elastic deformation capability of the spring plate and/or the suspension wire made of the memory metal (such as NiTi alloy) is far greater than that of the spring plate and/or the suspension wire made of the high-strength metal (such as Cu-Ni-Sn alloy (BF 158)). The spring and/or suspension wires made of memory metal can absorb more energy when impacted. The memory metal has the advantages of both metal and rubber, and the elastic sheet and/or the suspension wire made of the memory metal shows the linear elasticity of the conventional metal during normal work and shows the hyperelasticity like rubber when being impacted greatly.

Take the memory metal as NiTi alloy and the high-strength metal as Cu-Ni-Sn alloy (BF158) as an example. The stress-strain curves of the NiTi alloy and the Cu-Ni-Sn alloy (BF158) at 24 ℃ are shown in FIG. 7. It is known that NiTi alloys can withstand greater stress than Cu-Ni-Sn alloys (BF158), and that NiTi alloys can recover their original shape after stress relief.

Fig. 8 shows the impact resistance of a general metal (e.g., iron, copper, etc.), a high-strength metal (e.g., Cu — Ni — Sn alloy (BF158), etc.), a memory metal (e.g., NiTi alloy). As shown in fig. 8, the normal metal and the memory metal are largely deformed and the high-strength metal is less deformed when an impact load is applied. When the load is removed, the residual deformation of the common metal is large, the high-strength metal is easy to break, the risk of the memory metal breaking is low, and no residual deformation exists.

In some embodiments, the spring shown in fig. 9 may be used for impact simulation testing. In one example, the spring plate shown in fig. 9 may be used as the vertical spring plate shown in fig. 4a and 4 b. In one example, the spring plate shown in FIG. 9 has a width of 17mm and a thickness of 1 mm. In this embodiment, the spring plate may also be referred to as a spring plate.

In one illustrative example, the impact simulation test mode shown in FIG. 10 may be used for testing, as follows.

In the impact simulation test, the bottom of the elastic sheet is fixed, and a mass block connected with the elastic sheet at the top end of the elastic sheet is endowed with a downward initial speed. Wherein the mass m of the mass block is 3g, and the initial velocity v is 1 m/s. The maximum stress of the spring plate in the impact simulation test was then observed and recorded.

In one example, the impact simulation was performed on the spring plate made of the high-strength metal and the spring plate made of the memory metal, respectively, to compare the impact simulation results of the two. The high-strength metal is Cu-Ni-Sn alloy (BF158), and the stress failure criterion is as follows: 1200 MPa. The memory metal adopts Ni-Ti alloy, and the stress failure criterion is as follows: 1000 MPa. The simulation test method shown in fig. 10 is employed. As shown in fig. 11, in the whole process of the movement of the spring plate caused by the impact simulation test, the maximum stress of the spring plate made of high-strength metal reaches above 1400Mpa, far exceeding the failure criterion. The maximum stress of the shrapnel prepared by the memory metal is only 700-800MPa, which is less than the failure criterion, and the shrapnel can be completely recovered after the movement state is stable. Wherein in fig. 11, different gray scales represent different stress values.

The elastic sheet made of the high-strength metal and the elastic sheet made of the memory metal are installed in the voice coil motor to perform drop simulation, and the conclusion that the memory metal is higher in reliability than the high-strength metal can be obtained.

The focusing driving device provided by the embodiment of the application not only can realize focusing and optical anti-shake during shooting and improve the image definition of shot pictures or videos, but also has good impact resistance and can improve the reliability of the shooting function of electronic equipment.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (17)

1. A focus drive apparatus for an optical lens, the apparatus comprising:

a mover member for carrying the optical lens;

a stator component;

at least one focusing elastic part, one end of which is connected with the stator part and the other end of which is connected with the rotor part, so that the rotor part is suspended relative to the stator part; the optical lens can move along the optical axis direction of the optical lens under the driving of the rotor component;

the at least one focusing elastic component is made of shape memory alloy.

2. The device of claim 1, further comprising a resilient support member, the resilient support member being fabricated from a shape memory alloy.

3. The device of claim 2, wherein the resilient support member comprises a vertical spring; the upper end of the vertical elastic sheet is connected with the lens support, and the lower end of the vertical elastic sheet is fixed on the rotor component; the optical lens is fixed on the lens bracket;

the at least one focusing elastic member comprises an upper elastic member and a lower elastic member; the upper end of the rotor part is connected with the upper elastic part, and the lower end of the rotor part is connected with the lower elastic part; the upper elastic part is mounted on the stator part to suspend the mover part relative to the stator part.

4. The device of claim 3, wherein the mover member is located inside the stator member.

5. The apparatus of claim 3, wherein the apparatus comprises a plurality of mover members angularly evenly distributed in a first plane with respect to the optical axis, the first plane being perpendicular to the optical axis; the elastic supporting part comprises a plurality of vertical elastic sheets; the plurality of rotor parts correspond to the plurality of vertical elastic sheets one by one;

the optical lens can realize lens deflection under the driving of at least one of the plurality of rotor parts so as to realize optical anti-shake.

6. The apparatus of claim 2, wherein the at least one focusing resilient member comprises an upper resilient member and a lower resilient member;

one end of the stator component is connected with the upper elastic component, and the other end of the stator component is connected with the lower elastic component;

one end of the rotor part is connected with an upper elastic part, and the other end of the rotor part is connected with a lower elastic part, so that the rotor part is suspended relative to the stator part;

the elastic supporting part is a suspension wire, the upper end of the suspension wire is connected with the upper elastic part, and the lower end of the suspension wire is fixed on the base, so that the optical lens is suspended relative to the base, and the optical lens can move in parallel on a first plane under the drive of the stator part, wherein the first plane is vertical to the direction of the optical axis.

7. The device of claim 6, wherein the mover member is located inside the stator member.

8. The device of claim 1, wherein the shape memory alloy is any one of:

Ni-Ti-based alloy, Cu-based alloy, Fe-based alloy, Ag-based alloy.

9. The apparatus of claim 8, wherein the Ni-Ti based alloy is any one of:

NiTi alloy, NiTiCu alloy, NiTiPd alloy, NiTiFe alloy, NiTiNb alloy, NiTiGa alloy and NiTiCo alloy.

10. The apparatus of claim 9, wherein the Ni element of the NiTi alloy is present in an atomic percent of 50.6% to 51.3%.

11. The apparatus of claim 8, wherein the Cu-based alloy comprises any one of:

CuZn alloy, CuSn alloy, CuZnAl alloy, CuZnSi alloy, CuAlNi alloy, CuAlBe alloy, CuAlMn alloy.

12. The apparatus of claim 8, wherein the Fe-based alloy comprises any one of:

FePt alloy, FeNiNb alloy, FeMnSi alloy, FeNiC alloy, and FeNiCoTi alloy.

13. The apparatus of claim 8, wherein the Ag-based alloy comprises an AgCd alloy.

14. The device of claim 1, wherein the shape memory alloy is in an austenite phase in an unimpacted state of the at least one focus spring.

15. The device of claim 1, wherein the device is a voice coil motor.

16. A camera module comprising the device of any one of claims 1-15 and an optical lens.

17. An electronic device comprising the apparatus of any one of claims 1-15 and an optical lens.

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